WorldWideScience

Sample records for extracting nucleon magnetic

  1. Instanton effects on extracting the nucleon parton distributions

    Energy Technology Data Exchange (ETDEWEB)

    Mirjalili, A. [Physics Department, Yazd University, P.O.B 89195-741, Yazd (Iran, Islamic Republic of); School of Particles and Accelerators, IPM (Institute for Research in Fundamental Sciences) P.O.B 19395-5531, Tehran (Iran, Islamic Republic of); Dehghani, M. [Physics Department, Yazd University, P.O.B 89195-741, Yazd (Iran, Islamic Republic of); Yazdanpanah, M.M. [Physics Department, Kerman Shahid-Bahonar University, Kerman (Iran, Islamic Republic of); School of Particles and Accelerators, IPM (Institute for Research in Fundamental Sciences) P.O.B 19395-5531, Tehran (Iran, Islamic Republic of)

    2011-10-15

    In considering the nucleon parton distributions at low energy values, the non-perturbative effects will have an important role. It is usual to assume for the related vacuum a structure and attribute it a back ground field. It is very like to the situation which we have for Bohm-Aharnov effect when an electron moved in a region where there is not any magnetic field (vacuum). In this case we can attribute to the related vacuum a back ground field which is in fact the gauge field of electrodynamics force. The fluctuations which exist with respect to the concerned vacuum in QCD can appear as instantons and will effect on then nucleon parton distributions especially at low Bjorken-x values. A comparison between the proton structures when we consider the instanton effect with respect to the usual one, indicates the non-perturbative effect on extracting these functions. Considering this effect will yield a better result for the F{sub 2}{sup p} structure function.

  2. Strange Quark Magnetic Moment of the Nucleon at the Physical Point.

    Science.gov (United States)

    Sufian, Raza Sabbir; Yang, Yi-Bo; Alexandru, Andrei; Draper, Terrence; Liang, Jian; Liu, Keh-Fei

    2017-01-27

    We report a lattice QCD calculation of the strange quark contribution to the nucleon's magnetic moment and charge radius. This analysis presents the first direct determination of strange electromagnetic form factors including at the physical pion mass. We perform a model-independent extraction of the strange magnetic moment and the strange charge radius from the electromagnetic form factors in the momentum transfer range of 0.051  GeV^{2}≲Q^{2}≲1.31  GeV^{2}. The finite lattice spacing and finite volume corrections are included in a global fit with 24 valence quark masses on four lattices with different lattice spacings, different volumes, and four sea quark masses including one at the physical pion mass. We obtain the strange magnetic moment G_{M}^{s}(0)=-0.064(14)(09)μ_{N}. The four-sigma precision in statistics is achieved partly due to low-mode averaging of the quark loop and low-mode substitution to improve the statistics of the nucleon propagator. We also obtain the strange charge radius ⟨r_{s}^{2}⟩_{E}=-0.0043(16)(14)  fm^{2}.

  3. Sea quarks contribution to the nucleon magnetic moment and charge radius at the physical point

    Science.gov (United States)

    Sufian, Raza Sabbir; Yang, Yi-Bo; Liang, Jian; Draper, Terrence; Liu, Keh-Fei; χ QCD Collaboration

    2017-12-01

    We report a comprehensive analysis of the light and strange disconnected-sea quarks contribution to the nucleon magnetic moment, charge radius, and the electric and magnetic form factors. The lattice QCD calculation includes ensembles across several lattice volumes and lattice spacings with one of the ensembles at the physical pion mass. We adopt a model-independent extrapolation of the nucleon magnetic moment and the charge radius. We have performed a simultaneous chiral, infinite volume, and continuum extrapolation in a global fit to calculate results in the continuum limit. We find that the combined light and strange disconnected-sea quarks contribution to the nucleon magnetic moment is μM(DI )=-0.022 (11 )(09 ) μN and to the nucleon mean square charge radius is ⟨r2⟩E(DI ) =-0.019 (05 )(05 ) fm2 which is about 1 /3 of the difference between the ⟨rp2⟩E of electron-proton scattering and that of a muonic atom and so cannot be ignored in obtaining the proton charge radius in the lattice QCD calculation. The most important outcome of this lattice QCD calculation is that while the combined light-sea and strange quarks contribution to the nucleon magnetic moment is small at about 1%, a negative 2.5(9)% contribution to the proton mean square charge radius and a relatively larger positive 16.3(6.1)% contribution to the neutron mean square charge radius come from the sea quarks in the nucleon. For the first time, by performing global fits, we also give predictions of the light and strange disconnected-sea quarks contributions to the nucleon electric and magnetic form factors at the physical point and in the continuum and infinite volume limits in the momentum transfer range of 0 ≤Q2≤0.5 GeV2 .

  4. Extracting the σ-term from low-energy pion-nucleon scattering

    Science.gov (United States)

    Ruiz de Elvira, Jacobo; Hoferichter, Martin; Kubis, Bastian; Meißner, Ulf-G.

    2018-02-01

    We present an extraction of the pion-nucleon (π N) scattering lengths from low-energy π N scattering, by fitting a representation based on Roy–Steiner equations to the low-energy data base. We show that the resulting values confirm the scattering-length determination from pionic atoms, and discuss the stability of the fit results regarding electromagnetic corrections and experimental normalization uncertainties in detail. Our results provide further evidence for a large π N σ-term, {σ }π N=58(5) {{MeV}}, in agreement with, albeit less precise than, the determination from pionic atoms.

  5. Extraction of Electromagnetic Transition Form Factors for Nucleon Resonances within a Dynamical Coupled-Channels Model

    Energy Technology Data Exchange (ETDEWEB)

    N. Suzuki, T. Sato, T.-S. H. Lee

    2010-10-01

    We explain the application of a recently developed analytic continuation method to extract the electromagnetic transition form factors for the nucleon resonances ($N^*$) within a dynamical coupled-channel model of meson-baryon reactions.Illustrative results of the obtained $N^*\\rightarrow \\gamma N$ transition form factors, defined at the resonance pole positions on the complex energy plane, for the well isolated $P_{33}$ and $D_{13}$, and the complicated $P_{11}$ resonances are presented. A formula has been developed to give an unified representation of the effects due to the first two $P_{11}$ poles, which are near the $\\pi\\Delta$ threshold, but are on different Riemann sheets. We also find that a simple formula, with its parameters determined in the Laurent expansions of $\\pi N \\rightarrow \\pi N$ and $\\gamma N \\rightarrow\\pi N$ amplitudes, can reproduce to a very large extent the exact solutions of the considered model at energies near the real parts of the extracted resonance positions. We indicate the differences between our results and those extracted from the approaches using the Breit-Wigner parametrization of resonant amplitudes to fit the data.

  6. Extraction of nucleon axial charge and radius from lattice QCD results using baryon chiral perturbation theory

    Science.gov (United States)

    Yao, De-Liang; Alvarez-Ruso, Luis; Vicente-Vacas, Manuel J.

    2017-12-01

    We calculate the nucleon axial form factor up to the leading one-loop order in a covariant chiral effective field theory with the Δ (1232 ) resonance as an explicit degree of freedom. We fit the axial form factor to the latest lattice QCD data and pin down the relevant low-energy constants. The lattice QCD data, for various pion masses below 400 MeV, can be well described up to a momentum transfer of ˜0.6 GeV . The Δ (1232 ) loops contribute significantly to this agreement. Furthermore, we extract the axial charge and radius based on the fitted values of the low-energy constants. The results are gA=1.237 (74 ) and ⟨rA2⟩=0.263 (38 ) fm2 . The obtained coupling gA is consistent with the experimental value if the uncertainty is taken into account. The axial radius is below but in agreement with the recent extraction from neutrino quasielastic scattering data on deuterium, which has large error bars. Up to our current working accuracy, rA is predicted only at leading order, i.e., the one-loop level. A more precise determination might need terms of O (p5).

  7. Injection and extraction magnets: kicker magnets

    CERN Document Server

    Barnes, M J; Fowler, T; Senaj, V; Sermeus, L

    2010-01-01

    Each stage of an accelerator system has a limited dynamic range and therefore a chain of stages is required to reach high energy. A combination of septa and kicker magnets is frequently used to inject and extract beam from each stage. The kicker magnets typically produce rectangular field pulses with fast rise- and/or fall-times, however, the field strength is relatively low. To compensate for their relatively low field strength, the kicker magnets are generally combined with electromagnetic septa. The septa provide relatively strong field strength but are either DC or slow pulsed. This paper discusses injection and extraction systems with particular emphasis on the hardware required for the kicker magnet.

  8. Injection and extraction magnets: septa

    CERN Document Server

    Barnes, M J; Goddard, B; Hourican, M

    2010-01-01

    An accelerator has limited dynamic range: a chain of accelerators is required to reach high energy. A combination of septa and kicker magnets is frequently used to inject and extract beam from each stage. The kicker magnets typically produce rectangular field pulses with fast rise- and/or fall-times, however the field strength is relatively low. To compensate for their relatively low field strength, the kicker magnets are generally combined with electromagnetic septa. The septa provide relatively strong field strength but are either DC or slow pulsed. This paper discusses injection and extraction systems with particular emphasis on the hardware required for the septa.

  9. Discrete Symmetries on the Light Front and a General Relation connecting Nucleon Electric Dipole and Anomalous Magnetic Moments

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; /SLAC; Gardner, Susan; /Kentucky U.; Hwang, Dae Sung; /Sejong U.

    2006-01-11

    We consider the electric dipole form factor, F{sub 3}(q{sup 2}), as well as the Dirac and Pauli form factors, F{sub 1}(q{sup 2}) and F{sub 2}(q{sup 2}), of the nucleon in the light-front formalism. We derive an exact formula for F{sub 3}(q{sup 2}) to complement those known for F{sub 1}(q{sup 2}) and F{sub 2}(q{sup 2}). We derive the light-front representation of the discrete symmetry transformations and show that time-reversal- and parity-odd effects are captured by phases in the light-front wave functions. We thus determine that the contributions to F{sub 2}(q{sup 2}) and F{sub 3}(q{sup 2}), Fock-state by Fock-state, are related, independent of the fundamental mechanism through which CP violation is generated. Our relation is not specific to the nucleon, but, rather, is true of spin-1/2 systems in general, be they lepton or baryon. The empirical values of the anomalous magnetic moments, in concert with empirical bounds on the associated electric dipole moments, can better constrain theories of CP violation. In particular, we find that the neutron and proton electric dipole moments echo the isospin structure of the anomalous magnetic moments, {kappa}{sup n} {approx} -{kappa}{sup p}.

  10. MTN magnet for the SPS extracted beam.

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    This type of dipole magnet was used in the extracted beam lines of the North Area. It shows an opening for three different proton beam lines: a primary extracted proton beam, split by an upstream magnetic beam splitter (see photo 7612017) into three separated beams passes through different parts of its aperture: right, left up, left down. These magnets were designed to be concrete-insulated for radiation resistance. F. Streun stands on the right.

  11. The final inclusive and semi-inclusive longitudinal double-spin asymmetries at HERMES. Extraction of quark helicity distributions of the nucleon from deep-inelastic scattering

    Energy Technology Data Exchange (ETDEWEB)

    Kravchenko, Polina

    2010-10-15

    The thesis focuses on two aspects of the HERMES data analysis: the measurement of the semi-inclusive double spin asymmetries and the extraction of quark helicity distributions and quark polarizations of the nucleon from deep-inelastic scattering, as a possible interpretation of the HERMES data. The asymmetries are presented using all possible and accessible information about the HERMES data, including the latest systematic studies provided during the last years by HERMES collaboration. (orig.)

  12. SPS extraction kicker magnet thermal analysis

    CERN Document Server

    Timmins, M

    2004-01-01

    As the SPS accelerator will be used for the CNGS project and as LHC injector, the proton beams passing through its extraction kickers will have a much higher intensity than in the past. The image currents generated by this beam may provoke a temperature increase in the magnet's ferrite core to temperatures above the Curie temperature, unless the heat produced is effectively removed. A further complication arises from the fact that a high voltage is applied to the ferrites. The solution adopted consists in transferring the heat via Aluminium Nitride insulators to a water cooling circuit. The heat transfer analysis and the calculated thermal distribution of the magnet are presented.

  13. Nucleon electromagnetic form factors using lattice simulations at the physical point

    Science.gov (United States)

    Alexandrou, C.; Constantinou, M.; Hadjiyiannakou, K.; Jansen, K.; Kallidonis, Ch.; Koutsou, G.; Vaquero Aviles-Casco, A.

    2017-08-01

    We present results for the nucleon electromagnetic form factors using an ensemble of maximally twisted mass clover-improved fermions with pion mass of about 130 MeV. We use multiple sink-source separations and three analysis methods to probe ground-state dominance. We evaluate both the connected and disconnected contributions to the nucleon matrix elements. We find that the disconnected quark loop contributions to the isoscalar matrix elements are small, giving an upper bound of up to 2% of the connected and smaller than its statistical error. We present results for the isovector and isoscalar electric and magnetic Sachs form factors and the corresponding proton and neutron form factors. By fitting the momentum dependence of the form factors to a dipole form or to the z expansion, we extract the nucleon electric and magnetic radii, as well as the magnetic moment. We compare our results to experiment as well as to other recent lattice QCD calculations.

  14. Investigation of Central Pb-Pb Interactions at Energies of 160 GeV/Nucleon with the Help of the Emulsion Magnetic Chamber

    CERN Multimedia

    2002-01-01

    % EMU15 \\\\ \\\\ The aim of this experiment is to investigate high energy heavy ion central collisions by the use of emulsion magnetic chamber with high spatial resolution. The emulsion chamber consists of 50~emulsion layers 50~microns thick each coated on 25~microns mylar base. A thin lead target plate 300~microns thick is installed immediately in front of the first emulsion layer. It is placed in the transverse magnetic field B~$\\sim$~2~Tesla and is to be installed perpendicularly to Pb nucleus beam. This set-up enables to measure full 3-momenta and charge signs of secondary particles. \\\\ \\\\Specific goal is to carry out detailed analysis of individual events with super high multiplicity of secondaries. These data are to be used for investigation of properties of super hot/dense matter, in particular to look for and analyze possible manifestations of quark-gluon plasma in central Pb-Pb collisions at energies of 160~GeV/nucleon.

  15. DESIGN OF BEAM-EXTRACTION SEPTUM MAGNET FOR THE SNS.

    Energy Technology Data Exchange (ETDEWEB)

    TSOUPAS,N.; LEE,Y.Y.; RANK,J.; TUOZZOLO,J.

    2001-06-18

    The beam-extraction process from the SNS accumulator ring [1,2] requires a Lambertson septum magnet. In this paper we discuss the geometrical and magnetic field requirements of the magnet and present results obtained from two and three dimensional magnetic field calculations that shows the field quality in the regions of interest of the septum magnet.

  16. Study of the Few Nucleon Systems at CLAS

    Science.gov (United States)

    Zachariou, Nicholas

    2017-03-01

    The study of few nucleon systems with electromagnetic probes is an essential component of the scientific program carried out at the Thomas Jefferson National Accelerator Facility (JLab). Here we present measurements of exclusive reactions on light nuclei using real photon beams with energies up to 3 GeV and the CEBAF Large Acceptance Spectrometer (CLAS), a nearly 4π magnetic spectrometer, in order to study the properties of strongly interacting matter and the transition from hadronic (i.e in terms of nucleons and mesons) to partonic (in terms of quark and gluons) degrees of freedom in nuclear interactions. We discuss the progress made in understanding the relevant degrees of freedom using polarisation observables and cross sections of deuteron and ^3He photodisintegration in the few-GeV photon-energy region. In addition, recent high-statistics experiments with the CLAS detector have provided us with sufficient counting rates to study the effects of initial- and final-state interactions in reactions off the deuteron. Such data allow us to extract a large set of polarisation observables for final-state interactions in hyperon photoproduction and to study the properties of the hyperon-nucleon interaction. Initial-state effects are studied by mapping the dependence of experimental observables on the spectator-nucleon momentum. We also present recent results for polarisation observables for quasi-free K^+Λ off the bound proton in a deuteron as well as for final-state interactions in the reaction γ d→ K^+Λ n, and will discuss their impact on hyperon-nucleon studies.

  17. Nucleon Polarisabilities and Effective Field Theories

    Science.gov (United States)

    Griesshammer, Harald W.

    2017-09-01

    Low-energy Compton scattering probes the nucleon's two-photon response to electric and magnetic fields at fixed photon frequency and multipolarity. It tests the symmetries and strengths of the interactions between constituents, and with photons. For convenience, this energy-dependent information is often compressed into the two scalar dipole polarisabilities αE 1 and βM 1 at zero photon energy. These are fundamental quantities, and important for the proton charge radius puzzle and the Lamb shift of muonic hydrogen. Combined with emerging lattice QCD computations, they provide stringent tests for our understanding of hadron structure. Extractions of the proton and neutron polarisabilities from all published elastic data below 300 MeV in Chiral Effective Field Theory with explicit Δ (1232) are now available. This talk emphasises χEFT as natural bridge between lattice QCD and ongoing or approved efforts at HI γS, MAMI and MAX-lab. Chiral lattice extrapolations from mπ > 200 MeV to the physical point compare well to lattice computations. Combining χEFT with high-intensity experiments with polarised targets and polarised beams will extract not only scalar polarisabilities, but in particular the four so-far poorly explored spin-polarisabilities. These parametrise the stiffness of the spin in external electro-magnetic fields (nucleonic bi-refringence/Faraday effect). New chiral predictions for proton, deuteron and 3He observables show intriguing sensitivities on spin and neutron polarisabilities. Data consistency and a model-independent quantification of residual theory uncertainties by Bayesian analysis are also discussed. Proton-neutron differences explore the interplay between chiral symmetry breaking and short-distance Physics. Finally, I address their impact on the neutron-proton mass difference, big-bang nucleosynthesis, and their relevance for anthropic arguments. Supported in part by DOE DE-SC0015393 and George Washington University.

  18. Nucleon structure from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Dinter, Simon

    2012-11-13

    In this thesis we compute within lattice QCD observables related to the structure of the nucleon. One part of this thesis is concerned with moments of parton distribution functions (PDFs). Those moments are essential elements for the understanding of nucleon structure and can be extracted from a global analysis of deep inelastic scattering experiments. On the theoretical side they can be computed non-perturbatively by means of lattice QCD. However, since the time lattice calculations of moments of PDFs are available, there is a tension between these lattice calculations and the results from a global analysis of experimental data. We examine whether systematic effects are responsible for this tension, and study particularly intensively the effects of excited states by a dedicated high precision computation. Moreover, we carry out a first computation with four dynamical flavors. Another aspect of this thesis is a feasibility study of a lattice QCD computation of the scalar quark content of the nucleon, which is an important element in the cross-section of a heavy particle with the nucleon mediated by a scalar particle (e.g. Higgs particle) and can therefore have an impact on Dark Matter searches. Existing lattice QCD calculations of this quantity usually have a large error and thus a low significance for phenomenological applications. We use a variance-reduction technique for quark-disconnected diagrams to obtain a precise result. Furthermore, we introduce a new stochastic method for the calculation of connected 3-point correlation functions, which are needed to compute nucleon structure observables, as an alternative to the usual sequential propagator method. In an explorative study we check whether this new method is competitive to the standard one. We use Wilson twisted mass fermions at maximal twist in all our calculations, such that all observables considered here have only O(a{sup 2}) discretization effects.

  19. Few-Nucleon Systems

    Science.gov (United States)

    Viviani, Michele

    The recent theoretical advances in the study of the statical and dynamical properties of few-nucleon systems are here reported, with particular attention to the research activities performed under the Italian MURST-PRIN project FISICA DEL NUCLEO E DEI SISTEMI A PIÙ CORPI. The latter studies also include the development of methods for dealing with pionic degrees of freedom, the determination of static properties of light nuclei, and the computation of few-nucleon reaction observables, including electroweak processes.

  20. Amino-containing magnetic nanoemulsions: elaboration and nucleic acid extraction

    Energy Technology Data Exchange (ETDEWEB)

    Veyret, Raphael [Unite Mixte CNRS-bioMerieux-2714, Ecole Normale Superieure de Lyon, 46 allee d' Italie, 69364 Lyon (France); Delair, Thierry [Unite Mixte CNRS-bioMerieux-2714, Ecole Normale Superieure de Lyon, 46 allee d' Italie, 69364 Lyon (France); Pichot, Christian [Unite Mixte CNRS-bioMerieux-2714, Ecole Normale Superieure de Lyon, 46 allee d' Italie, 69364 Lyon (France); Elaissari, Abdelhamid [Unite Mixte CNRS-bioMerieux-2714, Ecole Normale Superieure de Lyon, 46 allee d' Italie, 69364 Lyon (France)]. E-mail: hamid.elaissari@ens-lyon.fr

    2005-08-15

    Amino-containing magnetic colloids were prepared from highly magnetic oil-in-water (O/W) emulsions. The functionalization was performed by controlling the adsorption of polyethyleneimine onto negatively charged magnetic emulsions. The cationic magnetic nanodroplets were characterized in terms of chemical composition, particle size, size distribution, zeta potential and colloidal stability as a function of storage time. These amino-containing magnetic emulsions were assessed as a new tool for nucleic acid extraction and amplification. The adsorption of nucleic acids was mostly controlled by attractive electrostatic interactions. The adsorption efficiency of a model RNA was found to be encouraging and the captured nucleic acid molecules were directly enzymatically amplified in the presence of the magnetic particles without any elution step.

  1. Location Fingerprint Extraction for Magnetic Field Magnitude Based Indoor Positioning

    Directory of Open Access Journals (Sweden)

    Wenhua Shao

    2016-01-01

    Full Text Available Smartphone based indoor positioning has greatly helped people in finding their positions in complex and unfamiliar buildings. One popular positioning method is by utilizing indoor magnetic field, because this feature is stable and infrastructure-free. In this method, the magnetometer embedded on the smartphone measures indoor magnetic field and queries its position. However, the environments of the magnetometer are rather harsh. This harshness mainly consists of coarse-grained hard/soft-iron calibrations and sensor electronic noise. The two kinds of interferences decrease the position distinguishability of the magnetic field. Therefore, it is important to extract location features from magnetic fields to reduce these interferences. This paper analyzes the main interference sources of the magnetometer embedded on the smartphone. In addition, we present a feature distinguishability measurement technique to evaluate the performance of different feature extraction methods. Experiments revealed that selected fingerprints will improve position distinguishability.

  2. Axial structure of the nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Veronique Bernard; Latifa Elouadrhiri; Ulf-G Meissner

    2002-01-01

    We review the current status of experimental and theoretical understanding of the axial nucleon structure at low and moderate energies. Topics considered include (quasi)elastic (anti)neutrino-nucleon scattering, charged pion electroproduction off nucleons and ordinary as well as radiative muon capture on the proton.

  3. Few-Nucleon Systems

    Science.gov (United States)

    Kievsky, A.

    2005-04-01

    Recent advances in the theoretical description of few-nucleon systems are reported. This research activity has been performed under the Italian project FISICA TEORICA DEL NUCLEO E DEI SISTEMI A MOLTI CORPI. Bound and scattering states as well as specific reactions are analyzed in connection with the current experimental activity.

  4. Application of orbital strong magnet in the extraction of deep orbital magnetic foreign bodies

    Directory of Open Access Journals (Sweden)

    Jin-Chen Jia

    2017-12-01

    Full Text Available AIM: To investigate the surgical method and efficacy of extraction of deep orbital magnetic foreign bodies by mean of an orbital strong magnet. METHODS: A retrospective analysis of clinical data of patients with deep orbital magnetic foreign bodies(OMFBin Hebei Eye Hospital from June 2014 to May 2017 was processed. A total of 23 eyes were enrolled, among them, 14 eyes of extraorbital OMFB, 9 eyes of intraorbital OMFB. The rate of extraction of foreign bodies and the postoperative complications were observed. RESULTS: All eyes of intraorbital foreign bodies were successfully extracted with 100% success rate. Twelve of 14 eyes of extraorbital foreign bodies were extracted with 86% success rate. Mild orbital hemorrhage were found in 2 eyes. There was no other obvious complication such as visual loss, orbital massive hemorrhage or limited ocular movement. CONCLUSION: It's an ideal surgical method to extract the deep orbital magnetic foreign bodies by mean of an orbital strong magnet, with mini-injury, high success rate, short duration and few complications.

  5. Parallel RNA extraction using magnetic beads and a droplet array

    Science.gov (United States)

    Shi, Xu; Chen, Chun-Hong; Gao, Weimin; Meldrum, Deirdre R.

    2015-01-01

    Nucleic acid extraction is a necessary step for most genomic/transcriptomic analyses, but it often requires complicated mechanisms to be integrated into a lab-on-a-chip device. Here, we present a simple, effective configuration for rapidly obtaining purified RNA from low concentration cell medium. This Total RNA Extraction Droplet Array (TREDA) utilizes an array of surface-adhering droplets to facilitate the transportation of magnetic purification beads seamlessly through individual buffer solutions without solid structures. The fabrication of TREDA chips is rapid and does not require a microfabrication facility or expertise. The process takes less than 5 minutes. When purifying mRNA from bulk marine diatom samples, its repeatability and extraction efficiency are comparable to conventional tube-based operations. We demonstrate that TREDA can extract the total mRNA of about 10 marine diatom cells, indicating that the sensitivity of TREDA approaches single-digit cell numbers. PMID:25519439

  6. Magnetic relaxation - coal swelling, extraction, pore size. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Doetschman, D.C.

    1994-10-26

    The aim of the contract was to employ electron and nuclear magnetic relaxation techniques to investigate solvent swelling of coals, solvent extraction of coals and molecular interaction with solvent coal pores. Many of these investigations have appeared in four major publications and a conference proceedings. Another manuscript has been submitted for publication. The set of Argonne Premium Coals was chosen as extensively characterized and representative samples for this project.

  7. Selective Extraction of Rare Earth Elements from Permanent Magnet Scraps with Membrane Solvent Extraction.

    Science.gov (United States)

    Kim, Daejin; Powell, Lawrence E; Delmau, Lætitia H; Peterson, Eric S; Herchenroeder, Jim; Bhave, Ramesh R

    2015-08-18

    The rare earth elements (REEs) such as neodymium, praseodymium, and dysprosium were successfully recovered from commercial NdFeB magnets and industrial scrap magnets via membrane assisted solvent extraction (MSX). A hollow fiber membrane system was evaluated to extract REEs in a single step with the feed and strip solutions circulating continuously through the MSX system. The effects of several experimental variables on REE extraction such as flow rate, concentration of REEs in the feed solution, membrane configuration, and composition of acids were investigated with the MSX system. A multimembrane module configuration with REEs dissolved in aqueous nitric acid solutions showed high selectivity for REE extraction with no coextraction of non-REEs, whereas the use of aqueous hydrochloric acid solution resulted in coextraction of non-REEs due to the formation of chloroanions of non-REEs. The REE oxides were recovered from the strip solution through precipitation, drying, and annealing steps. The resulting REE oxides were characterized with XRD, SEM-EDX, and ICP-OES, demonstrating that the membrane assisted solvent extraction is capable of selectively recovering pure REEs from the industrial scrap magnets.

  8. Platform construction and extraction mechanism study of magnetic mixed hemimicelles solid-phase extraction

    Science.gov (United States)

    Xiao, Deli; Zhang, Chan; He, Jia; Zeng, Rong; Chen, Rong; He, Hua

    2016-01-01

    Simple, accurate and high-throughput pretreatment method would facilitate large-scale studies of trace analysis in complex samples. Magnetic mixed hemimicelles solid-phase extraction has the power to become a key pretreatment method in biological, environmental and clinical research. However, lacking of experimental predictability and unsharpness of extraction mechanism limit the development of this promising method. Herein, this work tries to establish theoretical-based experimental designs for extraction of trace analytes from complex samples using magnetic mixed hemimicelles solid-phase extraction. We selected three categories and six sub-types of compounds for systematic comparative study of extraction mechanism, and comprehensively illustrated the roles of different force (hydrophobic interaction, π-π stacking interactions, hydrogen-bonding interaction, electrostatic interaction) for the first time. What’s more, the application guidelines for supporting materials, surfactants and sample matrix were also summarized. The extraction mechanism and platform established in the study render its future promising for foreseeable and efficient pretreatment under theoretical based experimental design for trace analytes from environmental, biological and clinical samples. PMID:27924944

  9. Nucleon-nucleon final state interactions in NN-->NNπ

    Science.gov (United States)

    Dubach, J.; Kloet, W. M.; Silbar, R. R.

    1986-01-01

    Peaks in cross sections for the NN-->NNπ reaction at low relative momentum for the final nucleon-nucleon pair are successfully explained using 1S0 and 3S1 final state interactions. Both singlet and triplet final state interactions are important and can interfere dramatically in certain spin observables.

  10. Nucleon-nucleon final state interactions in NN NN

    Energy Technology Data Exchange (ETDEWEB)

    Dubach, J.; Kloet, W.M.; Silbar, R.R.

    1986-01-01

    Peaks in cross sections for the NN NN reaction at low relative momentum for the final nucleon-nucleon pair are successfully explained using S0 and TS1 final state interactions. Both singlet and triplet final state interactions are important and can interfere dramatically in certain spin observables.

  11. All the states of the nucleon. Nucleon spectroscopy through the production of mesons; Le nucleon dans tous ses etats. Etude de la spectroscopie du nucleon via la photoproduction de mesons

    Energy Technology Data Exchange (ETDEWEB)

    Rebreyend, D

    2006-10-15

    The photoproduction of mesons on the nucleon gives a direct access to its spectroscopy and is a promising way for the study of the structure of the nucleon. The GRAAL experiment uses a tagged and polarized photon beam produced through the Compton diffusion of laser photons on the electrons circulating in the ESRF storage ring. The combination of this photon beam and an efficient detection system has allowed a series of measurements concerning the photoproduction of light mesons on the proton and on the neutron. The first 4 chapters are dedicated to the nucleon spectroscopy: the nucleon models and their consequences on the excited levels are recalled, the experimental technique used is described and the difficulties due to the extraction of relevant data are presented. Highly accurate measurements of cross-sections, {sigma} asymmetry beams and resonance parameters have been performed. The last part is dedicated to the principle of the measurement of the electric dipole momentum of the neutron. (A.C.)

  12. Nucleon Resonance Physics

    Energy Technology Data Exchange (ETDEWEB)

    Burkert, Volker D.

    2016-07-25

    Recent results of meson photo-production at the existing electron machines with polarized real photon beams and the measurement of polarization observables of the final state baryons have provided high precision data that led to the discovery of new excited nucleon and $\\Delta$ states using multi-channel partial wave analyses procedures. The internal structure of several prominent excited states has been revealed employing meson electroproduction processes. On the theoretical front, lattice QCD is now predicting the baryon spectrum with very similar characteristics as the constituent quark model, and continuum QCD, such as is represented in the Dyson-Schwinger Equations approach and in light front relativistic quark models, describes the non-perturbative behavior of resonance excitations at photon virtuality of $Q^2 > 1.5GeV^2$. In this talk I discuss the need to continue a vigorous program of nucleon spectroscopy and the study of the internal structure of excited states as a way to reveal the effective degrees of freedom underlying the excited states and their dependence on the distance scale probed.

  13. New measurements of high-momentum nucleons and short-range structures in nuclei

    CERN Document Server

    Fomin, N; Asaturyan, R; Benmokhtar, F; Boeglin, W; Bosted, P; Bruell, A; Bukhari, M H S; Chudakov, E; Clasie, B; Connell, S H; Dalton, M M; Daniel, A; Day, D B; Dutta, D; Ent, R; Fassi, L El; Fenker, H; Filippone, B W; Garrow, K; Gaskell, D; Hill, C; Holt, R J; Horn, T; Jones, M K; Jourdan, J; Kalantarians, N; Keppel, C E; Kiselev, D; Kotulla, M; Lindgren, R; Lung, A F; Malace, S; Markowitz, P; McKee, P; Meekins, D G; Mkrtchyan, H; Navasardyan, T; Niculescu, G; Opper, A K; Perdrisat, C; Potterveld, D H; Punjabi, V; Qian, X; Reimer, P E; Roche, J; Rodriguez, V M; Rondon, O; Schulte, E; Seely, J; Segbefia, E; Slifer, K; Smith, G R; Solvignon, P; Tadevosyan, V; Tajima, S; Tang, L; Testa, G; Trojer, R; Tvaskis, V; Vulcan, W F; Wasko, C; Wesselmann, F R; Wood, S A; Wright, J; Zheng, X

    2011-01-01

    We present new, high-Q^2 measurements of inclusive electron scattering from high-momentum nucleons in nuclei. This yields an improved extraction of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data extend to the kinematic regime where three-nucleon correlations are expected to dominate and we observe significantly greater strength in this region than previous measurements.

  14. Higher order terms of the nucleon current in the neutrino mass mechanism of neutrinoless double beta decay

    CERN Document Server

    Pantis, G

    2000-01-01

    The nuclear matrix elements for light and heavy Majorana neutrino in neutrinoless double beta decay have been reconsidered by including additional higher order terms in the nucleon current. The form of the nucleon current now includes except the usual vector and axial-vector terms additional contributions arising from weak magnetism and induced pseudoscalar coupling. The later is derived by the partially conserved axial-vector current hypothesis. We have considered all nuclei that undergo double beta decay in the mass region A=76 up to A=150 using the renormalized quasiparticle random phase approximation. Our results show that these contributions are very important. They bring significant reductions to the nuclear matrix element for both the light and the heavy neutrino. Thus new limits for the neutrino mass are extracted using the best presently available experimental limits on the half-life of neutrinoless double beta-decay.

  15. Nucleon Electromagnetic Form Factors

    Energy Technology Data Exchange (ETDEWEB)

    Marc Vanderhaeghen; Charles Perdrisat; Vina Punjabi

    2007-10-01

    There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has greatly improved by performing double polarization experiments, in comparison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at JLab, MAMI, and MIT-Bates. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed, including the recent progress in the determination of the valence quark generalized parton distributions of the nucleon, as well as the steady rate of improvements made in the lattice QCD calculations.

  16. Magnetic Partitioning Nanofluid for Rare Earth Extraction from Geothermal Fluids

    Energy Technology Data Exchange (ETDEWEB)

    McGrail, Bernard P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thallapally, Praveen K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Liu, Jian [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nune, Satish K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-08-21

    Rare earth metals are critical materials in a wide variety of applications in generating and storing renewable energy and in designing more energy efficient devices. Extracting rare earth metals from geothermal brines is a very challenging problem due to the low concentrations of these elements and engineering challenges with traditional chemical separations methods involving packed sorbent beds or membranes that would impede large volumetric flow rates of geothermal fluids transitioning through the plant. We are demonstrating a simple and highly cost-effective nanofluid-based method for extracting rare earth metals from geothermal brines. Core-shell composite nanoparticles are produced that contain a magnetic iron oxide core surrounded by a shell made of silica or metal-organic framework (MOF) sorbent functionalized with chelating ligands selective for the rare earth elements. By introducing the nanoparticles at low concentration (≈0.05 wt%) into the geothermal brine after it passes through the plant heat exchanger, the brine is exposed to a very high concentration of chelating sites on the nanoparticles without need to pass through a large and costly traditional packed bed or membrane system where pressure drop and parasitic pumping power losses are significant issues. Instead, after a short residence time flowing with the brine, the particles are effectively separated out with an electromagnet and standard extraction methods are then applied to strip the rare earth metals from the nanoparticles, which are then recycled back to the geothermal plant. Recovery efficiency for the rare earths at ppm level has now been measured for both silica and MOF sorbents functionalized with a variety of chelating ligands. A detailed preliminary techno-economic performance analysis of extraction systems using both sorbents showed potential to generate a promising internal rate of return (IRR) up to 20%.

  17. The structure of the nucleon

    CERN Document Server

    Thomas, Anthony William

    2001-01-01

    As the only stable baryon, the nucleon is of crucial importance in particle physics. Since the nucleon is a building block for all atomic nuclei, there is a need to analyse the its structure in order to fully understand the essential properties of all atomic nuclei. After more than forty years of research on the nucleon, both the experimental and theoretical situations have matured to a point where a synthesis of the results becomes indispensable. Here, A.W. Thomas and W. Weise present a unique report on the extensive empirical studies, theoretical foundations and the different models of t

  18. Bound Nucleon Form Factors, Quark-Hadron Duality, and the Nuclear EMC Effect

    Energy Technology Data Exchange (ETDEWEB)

    K. Tsushima; D.H. Lu; W. Melnitchouk; K. Saito; A.W. Thomas

    2002-09-13

    We discuss the electromagnetic form factors, axial form factors, and structure functions of a nucleon bound in the quark-meson coupling (QMC) model. Free space nucleon form factors are calculated using the improved cloudy bag model (ICBM). After describing finite nuclei and nuclear matter in the quark-based (EMC) model, the in-medium modification of the bound nucleon form factors is calculated in the same model. Finally, the bound nucleon structure function, F2, is extracted using the calculated in-medium electromagnetic form factors and Bloom-Gilman (quark-hadron) duality.

  19. Magnetic molecularly imprinted polymer for the selective extraction of quercetagetin from Calendula officinalis extract.

    Science.gov (United States)

    Ma, Run-Tian; Shi, Yan-Ping

    2015-03-01

    A new magnetic molecularly imprinted polymers (MMIPs) for quercetagetin was prepared by surface molecular imprinting method using super paramagnetic core-shell nanoparticle as the supporter. Acrylamide as the functional monomer, ethyleneglycol dimethacrylate as the crosslinker and acetonitrile as the porogen were applied in the preparation process. Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD) and Vibrating sample magnetometer (VSM) were applied to characterize the MMIPs, and High performance liquid chromatography (HPLC) was utilized to analyze the target analytes. The selectivity of quercetagetin MMIPs was evaluated according to their recognition to template and its analogues. Excellent binding for quercetagetin was observed in MMIPs adsorption experiment, and the adsorption isotherm models analysis showed that the homogeneous binding sites were distributed on the surface of the MMIPs. The MMIPs were employed as adsorbents in solid phase extraction for the determination of quercetagetin in Calendula officinalis extracts. Furthermore, this method is fast, simple and could fulfill the determination and extraction of quercetagetin from herbal extract. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Pseudo resonance behavior in nucleon-nucleon scattering

    Science.gov (United States)

    Kloet, W. M.; Tjon, J. A.; Silbar, Richard R.

    1981-02-01

    In a relativistic unitary model for intermediate energy nucleon-nucleon scattering there are strong indications that the resonance-like looping behavior of the 3F 3 and 1D 2 amplitudes is not due to a resonance pole but to the coupling with the inelastic NNπ channel. In its most simple form the looping behavior is caused by a square root branch cut.

  1. Nucleon-nucleon resonance behavior in an exactly soluble model

    Science.gov (United States)

    Kloet, W. M.; Tjon, J. A.

    1983-01-01

    The resonance-like structure in 1D 2 and 3F 3 nucleon-nucleon phase parameters at medium energy can be understood from the simple dynamics of coupling to the inelastic NNπ channel. In an exactly soluble coupled channel model the analytic structure of the scattering amplitude is studied in detail. The role of the NΔ branch cut and the presence and origin of dynamical poles is discussed.

  2. Nucleon-nucleon resonance behavior in an exactly soluble model

    Energy Technology Data Exchange (ETDEWEB)

    Kloet, W.M.; Tjon, J.A. (Rijksuniversiteit Utrecht (Netherlands). Inst. voor Theoretische Fysica)

    1983-01-17

    The resonance-like structure in /sup 1/D/sub 2/ and /sup 3/F/sub 3/ nucleon-nucleon phase parameters at medium energy can be understood from the simple dynamics of coupling to the inelastic NNsub(..pi..) channel. In an exactly soluble coupled channel model the analytic structure of the scattering amplitude is studied in detail. The role of the N..delta.. branch cut and the presence and origin of dynamical poles is discussed.

  3. The cosmological evolution of the nucleon mass and the electroweak coupling constants

    CERN Document Server

    Calmet, X; Calmet, Xavier; Fritzsch, Harald

    2002-01-01

    Starting from astrophysical indications that the fine structure constant might undergo a small time shift, we discuss the implications of such an effect from the point of view of particle physics. Grand unification implies small time shifts for the nucleon mass, the magnetic moment of the nucleon and the Fermi constant as well. The relative change of the nucleon mass is 123 times larger than the relative change of alpha. Astrophysical constraints indicate that the data from astrophysics are inconsistent, or the errors are largely underestimated. Laboratory measurements using very advanced methods in quantum optics might soon reveal small time shifts of the nucleon mass, the magnetic moment of the nucleon and the fine structure constant, thereby providing not only a breakthrough in the understanding of the unified particle interactions, but also an important cross-link between particle physics and cosmology.

  4. Use of Continuous Magnetic Extraction for removal of feedstock contaminants in flow-through mode

    DEFF Research Database (Denmark)

    Paulus, Anja; Fischer, Ingo; Hobley, Timothy John

    2014-01-01

    . However under such unusual conditions, new options for downstream processing are necessary such as Continuous Magnetic Extraction. The application of Continuous Magnetic Extraction in flow-through mode is demonstrated with soy whey as an example feed stream. The target molecule was the Bowman......-Birk protease inhibitor which has an anti-carcinogenic effect. It was found that using anion exchange magnetic particles as the impurity adsorbing agent, Continuous Magnetic Extraction of contaminants led to a BBI preparation with purity approaching 97% and with yield of 55% in a 15L pilot scale system....

  5. Flavor asymmetry of the nucleon sea and the five-quark components of the nucleons.

    Science.gov (United States)

    Chang, Wen-Chen; Peng, Jen-Chieh

    2011-06-24

    The existence of the five-quark Fock states for the intrinsic charm quark in the nucleons was suggested some time ago, but conclusive evidence is still lacking. We generalize the previous theoretical approach to the light-quark sector and study possible experimental signatures for such five-quark states. In particular, we compare the d-ū and ū + d-s-s data with the calculations based on the five-quark Fock states. The qualitative agreement between the data and the calculations is interpreted as evidence for the existence of the intrinsic light-quark sea in the nucleons. The probabilities for the |uuduū and |uuddd Fock states are also extracted.

  6. Relativistic quark-diquark model of baryons with a spin-isospin transition interaction: Non-strange baryon spectrum and nucleon magnetic moments

    Energy Technology Data Exchange (ETDEWEB)

    Sanctis, M. de [Universidad Nacional de Colombia, Bogota (Colombia); Ferretti, J. [Universita La Sapienza, Dipartimento di Fisica, Roma (Italy); INFN, Roma (Italy); Santopinto, E.; Vassallo, A. [INFN, Sezione di Genova, Genova (Italy)

    2016-05-15

    The relativistic interacting quark-diquark model of baryons, recently developed, is here extended introducing in the mass operator a spin-isospin transition interaction. This refined version of the model is used to calculate the non-strange baryon spectrum. The results are compared to the present experimental data. A preliminary calculation of the magnetic moments of the proton and neutron is also presented. (orig.)

  7. Hadron wave functions and the issue of nucleon deformation

    CERN Document Server

    Alexandrou, C; Tsapalis, A; Forcrand, Ph. de

    2003-01-01

    Using gauge invariant hadronic two- and three- density correlators we extract information on the spatial distributions of quarks in hadrons, and on hadron shape and multipole moments within quenched lattice QCD. Combined with the calculation of N to Delta transition amplitudes the issue of nucleon deformation can be addressed.

  8. NUCLEON POLARIZATION IN 3-BODY MODELS OF POLARIZED LI-6

    NARCIS (Netherlands)

    SCHELLINGERHOUT, NW; KOK, LP; COON, SA; ADAM, RM

    1993-01-01

    Just as He-3 --> can be approximately characterized as a polarized neutron target, polarized Li-6D has been advocated as a good isoscalar nuclear target for the extraction of the polarized gluon content of the nucleon. The original argument rests upon a presumed ''alpha + deuteron'' picture of Li-6,

  9. Electroexcitation of nucleon resonances

    Energy Technology Data Exchange (ETDEWEB)

    Inna Aznauryan, Volker D. Burkert

    2012-01-01

    We review recent progress in the investigation of the electroexcitation of nucleon resonances, both in experiment and in theory. The most accurate results have been obtained for the electroexcitation amplitudes of the four lowest excited states, which have been measured in a range of Q2 up to 8 and 4.5 GeV2 for the Delta(1232)P33, N(1535)S11 and N(1440)P11, N(1520)D13, respectively. These results have been confronted with calculations based on lattice QCD, large-Nc relations, perturbative QCD (pQCD), and QCD-inspired models. The amplitudes for the Delta(1232) indicate large pion-cloud contributions at low Q2 and don't show any sign of approaching the pQCD regime for Q2<7 GeV2. Measured for the first time, the electroexcitation amplitudes of the Roper resonance, N(1440)P11, provide strong evidence for this state as a predominantly radial excitation of a three-quark (3q) ground state, with additional non-3-quark contributions needed to describe the low Q2 behavior of the amplitudes. The longitudinal transition amplitude for the N(1535)S11 was determined and has become a challenge for quark models. Explanations may require large meson-cloud contributions or alternative representations of this state. The N(1520)D13 clearly shows the rapid changeover from helicity-3/2 dominance at the real photon point to helicity-1/2 dominance at Q2 > 0.5 GeV2, confirming a long-standing prediction of the constituent quark model. The interpretation of the moments of resonance transition form factors in terms of transition transverse charge distributions in infinite momentum frame is presented.

  10. Symmetry energy of cold nucleonic matter within a relativistic mean field model encapsulating effects of high-momentum nucleons induced by short-range correlations

    Science.gov (United States)

    Cai, Bao-Jun; Li, Bao-An

    2016-01-01

    It is well known that short-range nucleon-nucleon correlations (SRC) from the tensor components and/or the repulsive core of nuclear forces lead to a high- (low-)momentum tail (depletion) in the single-nucleon momentum distribution above (below) the nucleon Fermi surface in cold nucleonic matter. Significant progress was made recently in constraining the isospin-dependent parameters characterizing the SRC-modified single-nucleon momentum distribution in neutron-rich nucleonic matter using both experimental data and microscopic model calculations. Using the constrained single-nucleon momentum distribution in a nonlinear relativistic mean field (RMF) model, we study the equation of state (EOS) of asymmetric nucleonic matter (ANM), especially the density dependence of nuclear symmetry energy Esym(ρ ) . First, as a test of the model, the average nucleon kinetic energy extracted recently from electron-nucleus scattering experiments using a neutron-proton dominance model is well reproduced by the RMF model incorporating effects of the SRC-induced high-momentum nucleons, while it is significantly under predicted by the RMF model using a step function for the single-nucleon momentum distribution as in free Fermi gas (FFG) models. Second, consistent with earlier findings within nonrelativistic models, the kinetic symmetry energy of quasinucleons is found to be Esymkin(ρ0) =-16.94 ±13.66 MeV which is dramatically different from the prediction of Esymkin(ρ0) ≈12.5 MeV by FFG models at nuclear matter saturation density ρ0=0.16 fm-3 . Third, comparing the RMF calculations with and without the high-momentum nucleons using two sets of model parameters both reproducing identically all empirical constraints on the EOS of symmetric nuclear matter (SNM) and the symmetry energy of ANM at ρ0, the SRC-modified single-nucleon momentum distribution is found to make the Esym(ρ ) more concave around ρ0 by softening it significantly at both subsaturation and suprasaturation

  11. Measurements of e p →e'π+n at 1.6 extraction of nucleon resonance electrocouplings at CLAS

    Science.gov (United States)

    Park, K.; Aznauryan, I. G.; Burkert, V. D.; Adhikari, K. P.; Amaryan, M. J.; Pereira, S. Anefalos; Avakian, H.; Battaglieri, M.; Badui, R.; Bedlinskiy, I.; Biselli, A. S.; Bono, J.; Briscoe, W. J.; Brooks, W. K.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Doughty, D.; Dupre, R.; Egiyan, H.; Alaoui, A. El; Elouadrhiri, L.; Fassi, L. El; Eugenio, P.; Fedotov, G.; Fegan, S.; Fersch, R.; Filippi, A.; Fleming, J. A.; Garillon, B.; Garçon, M.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Joo, H. S.; Goetz, J. T.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guegan, B.; Guidal, M.; Guo, L.; Hakobyan, H.; Hanretty, C.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S. M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jenkins, D.; Jiang, H.; Jo, H. S.; Joo, K.; Joosten, S.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Kuhn, S. E.; Kuleshov, S. V.; Lenisa, P.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; Martinez, D.; McKinnon, B.; Mokeev, V.; Montgomery, R. A.; Moutarde, H.; Camacho, C. Munoz; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Pasyuk, E.; Peng, P.; Phelps, W.; Phillips, J. J.; Pisano, S.; Pogorelko, O.; Price, J. W.; Procureur, S.; Prok, Y.; Protopopescu, D.; Puckett, A. J. R.; Raue, B. A.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Sharabian, Y. G.; Simonyan, A.; Skorodumina, Iu.; Smith, E. S.; Smith, G. D.; Sparveris, N.; Stoler, P.; Strakovsky, I. I.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tang, W.; Taylor, C. E.; Tian, Ye; Trivedi, A.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.; CLAS Collaboration

    2015-04-01

    Differential cross sections of the exclusive process e p →e'π+n were measured with good precision in the range of the photon virtuality Q2=1.8 -4.5 GeV2 and the invariant mass range of the π+n final state W =1.6 -2.0 GeV using the Continuous Electron Beam Accelerator Facility Large Acceptance Spectrometer. Data were collected with nearly complete coverage in the azimuthal and polar angles of the n π+ center-of-mass system. More than 37 000 cross-section points were measured. The contributions of the isospin I =1/2 resonances N (1675 ) 5/2-,N (1680 ) 5/2+ , and N (1710 ) 1/2+ were extracted at different values of Q2 using a single-channel, energy-dependent resonance amplitude analysis. Two different approaches, the unitary isobar model and the fixed-t dispersion relations, were employed in the analysis. We observe significant strength of the N (1675 ) 5/2- in the A1 /2 amplitude, which is in strong disagreement with quark models that predict both transverse amplitudes to be strongly suppressed. For the N (1680 ) 5/2+ we observe a slow changeover from the dominance of the A3 /2 amplitude at the real photon point (Q2=0 ) to a Q2 where A1 /2 begins to dominate. The scalar amplitude S1 /2 drops rapidly with Q2 consistent with quark model prediction. For the N (1710 ) 1/2+ resonance our analysis shows significant strength for the A1 /2 amplitude at Q2<2.5 GeV2.

  12. Nucleon spin decomposition and orbital angular momentum in the nucleon

    Science.gov (United States)

    Wakamatsu, Masashi

    2014-09-01

    To get a complete decomposition of nucleon spin is a fundamentally important homework of QCD. In fact, if our researches end up without accomplishing this task, a tremendous efforts since the 1st discovery of the nucleon spin crisis would end in the air. We now have a general agreement that there are at least two physically inequivalent gauge-invariant decompositions of the nucleon. In these two decompositions, the intrinsic spin parts of quarks and gluons are just common. What discriminate these two decompositions are the orbital angular momentum (OAM) parts. The OAMs of quarks and gluons appearing in the first decomposition are the so-called ``mechanical'' OAMs, while those appearing in the second decomposition are the generalized (gauge-invariant) ``canonical'' ones. By this reason, these decompositions are broadly called the ``mechanical'' and ``canonical'' decompositions of the nucleon spin. Still, there remains several issues, which have not reached a complete consensus among the experts. (See the latest recent). In the present talk, I will mainly concentrate on the practically most important issue, i.e. which decomposition is more favorable from the observational viewpoint. There are two often-claimed advantages of canonical decomposition. First, each piece of this decomposition satisfies the SU(2) commutation relation or angular momentum algebra. Second, the canonical OAM rather than the mechanical OAM is compatible with free partonic picture of constituent orbital motion. In the present talk, I will show that both these claims are not necessarily true, and push forward a viewpoint that the ``mechanical'' decomposition is more physical in that it has more direct connection with observables. I also emphasize that the nucleon spin decomposition accessed by the lattice QCD analyses is the ``mechanical'' decomposition not the ``canonical'' one. The recent lattice QCD studies of the nucleon spin decomposition are also briefly overviewed.

  13. Polarized lepton-nucleon scattering

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, E. [Stanford Univ., CA (United States)

    1994-12-01

    The author provides a summary of the proposed and published statistical (systematic) uncertainties from the world experiments on nucleon spin structure function integrals. By the time these programs are complete, there will be a vast resource of data on nucleon spin structure functions. Each program has quite different experimental approaches regarding the beams, targets, and spectrometers thus ensuring systematically independent tests of the spin structure function measurements. Since the field of spin structure function measurements began, there has been a result appearing approximately every five years. With advances in polarized target technology and high polarization in virtually all of the lepton beams, results are now coming out each year; this is a true signature of the growth in the field. Hopefully, the experiments will provide a consistent picture of nucleon spin structure at their completion. In summary, there are still many open questions regarding the internal spin structure of the nucleon. Tests of QCD via the investigation of the Bjorken sum rule is a prime motivator for the field, and will continue with the next round of precision experiments. The question of the origin of spin is still a fundamental problem. Researchers hope is that high-energy probes using spin will shed light on this intriguing mystery, in addition to characterizing the spin structure of the nucleon.

  14. Generalized polarizabilities of the nucleon in baryon chiral perturbation theory

    Science.gov (United States)

    Lensky, Vadim; Pascalutsa, Vladimir; Vanderhaeghen, Marc

    2017-02-01

    The nucleon generalized polarizabilities (GPs), probed in virtual Compton scattering (VCS), describe the spatial distribution of the polarization density in a nucleon. They are accessed experimentally via the process of electron-proton bremsstrahlung (ep→ epγ ) at electron-beam facilities, such as MIT-Bates, CEBAF (Jefferson Lab), and MAMI (Mainz). We present the calculation of the nucleon GPs and VCS observables at next-to-leading order in baryon chiral perturbation theory (Bχ PT), and confront the results with the empirical information. At this order our results are predictions, in the sense that all the parameters are well known from elsewhere. Within the relatively large uncertainties of our calculation we find good agreement with the experimental observations of VCS and the empirical extractions of the GPs. We find large discrepancies with previous chiral calculations - all done in heavy-baryon χ PT (HBχ PT) - and discuss the differences between Bχ PT and HBχ PT responsible for these discrepancies.

  15. Carbon coated magnetic nanoparticles as a novel magnetic solid phase extraction adsorbent for simultaneous extraction of methamphetamine and ephedrine from urine samples.

    Science.gov (United States)

    Taghvimi, Arezou; Hamishehkar, Hamed

    2017-01-15

    This paper develops a highly selective, specific and efficient method for simultaneous determination of ephedrine and methamphetamine by a new carbon coated magnetic nanoparticles (C/MNPs) as a magnetic solid phase extraction (MSPE) adsorbent in biological urine medium. The characterization of synthesized magnetic nano adsorbent was completely carried out by various characterization techniques like Fourier transform infrared (FT-IR) spectroscopy, powder x-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). Nine important parameters influencing extraction efficiency including amount of adsorbent, amounts of sample volume, pH, type and amount of extraction organic solvent, time of extraction and desorption, agitation rate and ionic strength of extraction medium, were studied and optimized. Under optimized extraction conditions, a good linearity was observed in the concentration range of 100-2000ng/mL for ephedrine and 100-2500ng/mL for methamphetamine. Analysis of positive urine samples was carried out by proposed method with the recovery of 98.71 and 97.87% for ephedrine and methamphetamine, respectively. The results indicated that carbon coated magnetic nanoparticles could be applied in clinical and forensic laboratories for simultaneous determination of abused drugs in urine media. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. One-stop genomic DNA extraction by salicylic acid-coated magnetic nanoparticles.

    Science.gov (United States)

    Zhou, Zhongwu; Kadam, Ulhas S; Irudayaraj, Joseph

    2013-11-15

    Salicylic acid-coated magnetic nanoparticles were prepared via a modified one-step synthesis and used for a one-stop extraction of genomic DNA from mammalian cells. The synthesized magnetic particles were used for magnetic separation of cells from the media by nonspecific binding of the particles as well as extraction of genomic DNA from the lysate. The quantity and quality were confirmed by agarose gel electrophoresis and polymerase chain reaction. The entire process of extraction and isolation can be completed within 30 min. Compared with traditional methods based on centrifugation and filtration, the established method is fast, simple, reliable, and environmentally friendly. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Peripheral scattering of nucleons by isoscalar targets

    Energy Technology Data Exchange (ETDEWEB)

    Higa, R. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica. Grupo de Fenomenologia de Particulas Elementares e Teoria Nuclear]. E-mail: higa@if.usp.br

    2001-07-01

    As is well known, the exchange of a single pion does not contribute to scattering of nucleons by isoscalar targets, since the pion is an isovector. This simple idea were employed in a recent work in order to probe the next layer of NN interaction and we showed that a clear dependence of phase shifts on the NN potential is obtained. As N{alpha} scattering data is still not free of ambiguity, few conclusions can be extracted. Motivated by more precise Nd scattering data recently available, we began a new study of Nd system. This give us more information about the intermediate region of NN potential, but first we need to study the techniques involved in extracting phase shifts and mixing parameters. (author)

  18. Nucleon structure observables with PANDA

    Science.gov (United States)

    Mora EspÍ, MarÍa Carmen

    2017-12-01

    The PANDA detector will be built as a part of the future FAIR facility in Darmstadt. The availability of an antiproton beam with beam momenta up to 15 GeV/c will make possible a broad nuclear physics program. Topics like hadron spectroscopy in the charmonium mass region, the property of hadrons inside nuclear matter, hypernuclear physics, or nucleon properties using electromagnetic processes are part of the physics program of PANDA. The main part of this contribution concentrates on the feasibility of measurement of nucleon structure observables, such as electromagnetic form factors or transition distribution amplitudes, via experiments using electromagnetic processes in PANDA.

  19. Stopped nucleons in configuration space

    Energy Technology Data Exchange (ETDEWEB)

    Bialas, Andrzej [Jagellonian Univ., Krakow (Poland); Bzdak, Adam [AGH - Univ. of Science and Technology, Krakow (Poland); Koch, Volker [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-05-09

    In this note, using the colour string model, we study the configuration space distribution of stopped nucleons in heavy-ion collisions. We find that the stopped nucleons from the target and the projectile end up separated from each other by the distance increasing with the collision energy. In consequence, for the center of mass energies larger than 6 or 10 GeV (depending on the details of the model) it appears that the system created is not in thermal and chemical equilibrium, and the net baryon density reached is likely not much higher than that already present in the colliding nuclei.

  20. Hammer events, neutrino energies, and nucleon-nucleon correlations

    CERN Document Server

    Weinstein, L B; Piasetzky, E

    2016-01-01

    Neutrino oscillation measurements depend on a difference between the rate of neutrino-nucleus interactions at different neutrino energies or different distances from the source. Knowledge of the neutrino energy spectrum and neutrino-detector interactions are crucial for these experiments. Short range nucleon-nucleon correlations in nuclei (SRC) affect properties of nuclei. The ArgoNeut liquid Argon Time Projection Chamber (lArTPC) observed neutrino-argon scattering events with two protons back-to-back in the final state ("hammer" events) which they associated with SRC pairs. The MicroBoone lArTPC will measure far more of these events. We simulate hammer events using two simple models. We use the well-known electron-nucleon cross section to calculate e-argon interactions where the e- scatters from a proton, ejecting a pi+, and the pi+ is then absorbed on a moving deuteron-like $np$ pair. We also use a model where the electron excites a nucleon to a Delta, which then deexcites by interacting with a second nucle...

  1. Nucleonic coal detector with independent, hydropneumatic suspension

    Science.gov (United States)

    Jones, E. W.; Handy, K.

    1977-01-01

    The design of a nucleonic, coal interface detector which measures the depth of coal on the roof and floor of a coal mine is presented. The nucleonic source and the nucleonic detector are on independent hydropneumatic suspensions to reduce the measurement errors due to air gap.

  2. Transversity of quarks in a nucleon

    Indian Academy of Sciences (India)

    The transversity distribution of quarks in a nucleon is one of the three fundamental distributions, that characterize nucleon's properties in hard scattering processes at leading twist (twist 2). It measures the distribution of quark transverse spin in a nucleon polarized transverse to its (infinite) momentum. It is a chiral-odd ...

  3. Flavor asymmetry of the nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Bijker, R. [Instituto de Ciencias Nucleares, UNAM, Apartado Postal 70-543, 04510 Mexico D. F. (Mexico); Santopinto, E. [INFN and Dipartimento di Fisica, Via Dodecaneso 33, I-16146 Genova (Italy)]. e-mail: bijker@nucleares.unam.mx

    2008-12-15

    The flavor asymmetry of the nucleon sea is discussed in an unquenched quark model for baryons in which the effects of quark-antiquark pairs (uu, dd and ss) are taken into account in an explicit form. The inclusion of qq pairs leads automatically to an excess of d over u quarks in the proton, in agreement with experimental data. (Author)

  4. Flavor content of nucleon form factors

    Energy Technology Data Exchange (ETDEWEB)

    Bijker, R. [Departamento de Estructura de la Materia, lnstituto de Ciencias Nucleares, UNAM, AP 70-543, 04510 Mexico D.F. (Mexico); Santopinto, E [l.N.F.N. and Dipartimento di Fisica, via Dodecaneso 33, Genova, I-16146 (Italy)]. e-mail: bijkernucleares. unam. mx

    2007-12-15

    The flavor content of nucleon form factors is analyzed using two different theoretical approaches. The first is based on a phenomenological two-component model in which the external photon couples to both an intrinsic three-quark structure and a meson cloud via vector-meson dominance. The flavor content of the nucleon form factors is extracted without introducing any additional parameter. A comparison with recent data from parity-violating electron scattering experiments shows a good overall agreement for the strange form factors. A more microscopic approach is that of an unquenched quark model proposed by Geiger and Isgur which is based on valence quark plus glue dominance to which quark-antiquark pairs are added in perturbation. In the original version the importance of ss loops in the proton was studied. Here we present the formalism for a new generation of unquenched quark models which, among other extensions, includes the contributions of uu and dd loops. Finally, we discuss some preliminary results in the closure limit. (Author)

  5. Pyrolytic in situ magnetization of metal-organic framework MIL-100 for magnetic solid-phase extraction.

    Science.gov (United States)

    Huo, Shu-Hui; An, Hai-Yan; Yu, Jing; Mao, Xue-Feng; Zhang, Zhe; Bai, Lei; Huang, Yan-Feng; Zhou, Peng-Xin

    2017-09-29

    In this study, we report a facile, environmental friendly fabrication of a type of magnetic metal-organic framework (MOF) MIL-100 that can be used for magnetic solid-phase extraction (MSPE). The magnetic MOF composites were fabricated using in situ calcination method. The as-synthesized materials exhibited both high porosity and magnetic characteristics. They used for the MSPE of polycyclic aromatic hydrocarbons (PAHs) from water samples. Such MOF-based magnetic solid-phase extraction in combination with gas chromatography equipped with a flame ionization detector (GC-FID), exhibited wide linearity (0.02-250μgL-1), low detection limits (4.6-8.9ngL-1), and high enrichment factors (452-907) for PAHs. The relative standard deviations (RSDs) for intra- and inter-day extractions of PAHs were ranging from 1.7% to 9.8% and 3.8% to 9.2%, respectively. The recoveries for spiked PAHs (1μgL-1) in water samples were in the range of 88.5% to 106.6%. The results showed that the special anion-π orbital (electron donor-acceptor) interaction and π-π stacking between magnetic MIL-100 and PAHs play an important role in the adsorption of PAHs. Copyright © 2017. Published by Elsevier B.V.

  6. Leading order relativistic chiral nucleon-nucleon interaction

    Science.gov (United States)

    Ren, Xiu-Lei; Li, Kai-Wen; Geng, Li-Sheng; Long, Bingwei; Ring, Peter; Meng, Jie

    2018-01-01

    Motivated by the successes of relativistic theories in studies of atomic/molecular and nuclear systems and the need for a relativistic chiral force in relativistic nuclear structure studies, we explore a new relativistic scheme to construct the nucleon-nucleon interaction in the framework of covariant chiral effective field theory. The chiral interaction is formulated up to leading order with covariant power counting and a Lorentz invariant chiral Lagrangian. We find that the relativistic scheme induces all six spin operators needed to describe the nuclear force. A detailed investigation of the partial wave potentials shows a better description of the {}1S0 and {}3P0 phase shifts than the leading order Weinberg approach, and similar to that of the next-to-leading order Weinberg approach. For the other partial waves with angular momenta J≥slant 1, the relativistic results are almost the same as their leading order non-relativistic counterparts. )

  7. Parity violation in the nucleon-nucleon interaction

    Energy Technology Data Exchange (ETDEWEB)

    Haeberli, W.

    1981-01-01

    A short review is presented of experiments designed to detect parity nonconservation (PNC) in the interaction between nucleons. A recent measurement of PNC in proton-proton scattering is described, and some of the methods which were developed to reduce systematic errors to less than or equal to 2 x 10/sup -8/ are discussed. The results of this experiment and of other measurements on PNC are compared to theoretical predictions.

  8. Nucleon-antinucleon annihilation dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Dover, C.B.

    1988-01-01

    Recent progress towards a microscopic understanding of nucleon- antinucleon N/ovr N/ annihilation is reviewed. We consider statistical models, the constraints imposed by SU(2) or SU(3) flavor symmetry and the spin-flavor-color dependence of effective operators for the creation/destruction of quark-antiquark (Q/ovr Q/) pairs in N/ovr N/ annihilation processes. The importance of dynamical selection rules is emphasized as a means of revealing the underlying reaction mechanism. 15 refs., 1 fig.

  9. PEGylation of magnetic multi-walled carbon nanotubes for enhanced selectivity of dispersive solid phase extraction.

    Science.gov (United States)

    Zeng, Qiong; Liu, Yi-Ming; Jia, Yan-Wei; Wan, Li-Hong; Liao, Xun

    2017-02-01

    Carbon nanotubes (CNTs) possess large potential as extraction absorbents in solid phase extraction. They have been widely applied in biomedicine research, while very rare application in natural product chemistry has been reported. In this work, methoxypolyethylene glycol amine (mPEG-NH2) is covalently coupled to CNTs-magnetic nanoparticles (CNTs-MNP) to prepare a novel magnetic nanocomposite (PEG-CNTs-MNP) for use as dispersive solid-phase extraction (DSPE) absorbent. The average particle size was 86nm, and the saturation magnetization was 52.30emu/g. This nanocomposite exhibits excellent dispersibility in aqueous systems, high selectivity and fast binding kinetics when used for extraction of Z-ligustilide, the characteristic bioactive compound from two popular Asian herbal plants, R. chuanxiong and R. ligusticum. HPLC quantification of Z-ligustilide extracted from the standard sample solution showed a high recovery of 98.9%, and the extraction rate from the extracts of the above two herbs are both around 70.0%. To our knowledge, this is the first report on using PEG-CNTs-MNP as DSPE nanosorbents for selective extraction of natural products. This nano-material has promising application in isolation and enrichment of targeted components from complex matrices. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Extraction and determination of trace amounts of chlorpromazine in biological fluids using magnetic solid phase extraction followed by HPLC

    Directory of Open Access Journals (Sweden)

    Yadollah Yamini

    2014-08-01

    Full Text Available A simple, rapid and sensitive method termed as magnetic solid phase extraction (MSPE combined with high-performance liquid chromatography-ultraviolet detector (HPLC-UV has been proposed for the determination of trace amounts of chlorpromazine (CPZ in water, urine and plasma samples. The separation and determination was performed on a C18 column under the optimal chromatographic conditions. Several factors influencing the extraction efficiency of CPZ, such as pH, surfactant and adsorbent amounts, ionic strength, extraction time, sample volume and desorption conditions, were studied and optimized. Under the optimal MSPE conditions, the extraction percentage of CPZ was 74%, 27% and 16% in water, urine and plasma samples, respectively. The limits of detection (LODs of the proposed approach were 0.1, 5.0 and 10 ng/mL in water, urine and plasma samples, respectively. The relative standard deviations (RSDs based on five replicate determinations at 10 ng/mL level of CPZ was 1.2%. Good linear behaviors over the investigated concentration ranges (0.25–300 ng/mL with good coefficient of determination, R2>0.9998, were obtained. Good spike recoveries with relative errors less than 9.0% were obtained when applying the proposed method to water, urine and plasma samples. Keywords: Chlorpromazine, Magnetic solid phase extraction, Mixed-hemimicelles

  11. Energy extraction system using dual-capacitor switching for quench protection of HTS magnet

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Yo Jong; Song, Seung Hyun; Jeon, Hae Ryong; Ko, Tae Kuk [Yonsei University, Seoul (Korea, Republic of); Lee, Woo Seung [JH ENGINEERING CO., LTD., Anyang (Korea, Republic of); Kang, Hyoung Ku [Korea National University of Transportation, Chungju (Korea, Republic of)

    2017-09-15

    The superconducting magnets have a large inductance as well as high operating current. Therefore, mega-joule scale energy can be stored in the magnet. The energy stored in the magnet is sufficient to damage the magnet when a quench occurs. Quench heater and dump resistor can be used to protect the magnet. However, using quench heater to create quench resistors through heat transfer can be slower than instantly switching resistors. Also, electrical short, overheating and breakdown can occur due to quench heater. Moreover, the number of dump resistor should be limited to avoid large terminal voltage. Therefore, in this paper, we propose a quench protection method for extracting the energy stored in a magnet by charging and discharging energy through a capacitor switching without increasing resistance. The simulation results show that the proposed system has a faster current decay within the allowable voltage level.

  12. Effects of Magnet Errors in the ILC 14 mrad Extraction Line

    Energy Technology Data Exchange (ETDEWEB)

    Toprek, Dragan; /VINCA Inst. Nucl. Sci., Belgrade; Nosochkov, Yuri; /SLAC

    2009-05-08

    The ILC baseline extraction line is designed for 14 mrad horizontal crossing angle between e{sup +} and e{sup -} colliding beams at Interaction Point (IP). The extraction optics in the Interaction Region (IR) includes a detector integrated dipole field (anti-DID) to reduce orbit perturbation caused by the detector solenoid and minimize detector background. This paper presents a study of random field and alignment errors in the extraction magnets, compensation of the induced orbit perturbation, and effects of errors on extraction beam power loss. The results are obtained for the baseline ILC energy of 500 GeV center-of-mass and three options of beam parameters.

  13. Population of 13Be with a Nucleon-Exchange Reaction

    Science.gov (United States)

    Marks, Bradon; Deyoung, Paul; Smith, Jenna; Thoennessen, Michael; MoNA Collaboration

    2015-10-01

    Neutron-unbound nuclei are traditionally formed by the removal of one or more nucleons from a fast beam of ions. This method often results in a background, which is difficult to separate from the particle of interest. Nucleon-removal entrance-channels also require the ion beam to be more massive than the particle of interest, which presents the additional challenges of the beam being difficult to make. The present work was done with a nucleon-exchange entrance channel. At the National Superconducting Cyclotron Laboratory, a 71 MeV/u 13B beam impinged on a 47 mg/cm2 thick target of 9Be. As a result numerous reactions occurred, including the population of 13Be through the nucleon-exchange entrance-channel. The 13Be nuclei decayed to 12Be and one neutron in approximately 10-21 seconds. The resulting neutrons were detected by either the Modular Neutron Array (MoNA) or the Large multi-Institution Scintillator Array (LISA), while the 12Be nuclei were directed through an array of charged particle detectors by a 4T superconducting sweeper magnet. The four-momentum vectors of the fragment nucleus and the neutron were calculated to determine the decay energy of 13Be. Monte-Carlo simulations consistent with results from previous analyses of 13Be were satisfactorily fit to the decay-energy spectrum. Additionally, the cross-section for the nucleon-exchange entrance-channel is consistent with a theoretical prediction. This material is based upon work supported by the National Science Foundation under Grant No. PHY-1306074.

  14. Temperature responsive hydrogel magnetic nanocomposites for hyperthermia and metal extraction applications

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, N. Narayana, E-mail: nagireddynarayana@gmail.com [Center for Advanced Biomaterials for Healthcare, Istituto Italiano di Tecnologia@CRIB, Largo Barsanti e Matteucci 53, 80125 Napoli (Italy); Ravindra, S. [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Johannesburg 1709 (South Africa); Reddy, N. Madhava [Department of Environmental Science, Gates Institute of Technology, NH-7, Gooty, Anantapuram, Andhra Pradesh (India); Rajinikanth, V. [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Johannesburg 1709 (South Africa); Raju, K. Mohana [Synthetic Polymer Laboratory, Department of Polymer Science & Technology, S.K. University, Anantapuram, Andhra Pradesh (India); Vallabhapurapu, Vijaya Srinivasu [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Johannesburg 1709 (South Africa)

    2015-11-15

    The present work deals with the development of temperature and magnetic responsive hydrogel networks based on poly (N-isopropylacrylamide)/acrylamido propane sulfonic acid. The hydrogel matrices are synthesized by polymerizing N-isopropylacrylamide (NIPAM) monomer in the presence of acrylamido propane sulphonicacid (AMPS) using a cross-linker (N,N-methylenebisacrylamide, MBA) and redox initiating system [ammonium persulphate (APS)/tetramethylethylenediamine (TMEDA)]. The magnetic nanoparticles are generated throughout the hydrogel networks using in situ method by incorporating iron ions and subsequent treatment with ammonia. A series of hydrogel-magnetic nanocomposites (HGMNC) are developed by varying AMPS composition. The synthesized hydrogel magnetic nanocomposites (HGMNC) are characterized by using Fourier Transform Infrared (FTIR) Spectroscopy, X-ray diffraction (XRD), Thermal Analyses and Electron Microscopy analysis (Scanning and Transmission Electron Microscope). The metal extraction capacities of the prepared hydrogel (HG) and hydrogel magnetic nanocomposites (HGMNC) were studied at different temperatures. The results suggest that HGMNCs have higher extraction capacity compared to HG and HG loaded iron ions. This data also reveals that the extraction of metals by hydrogel magnetic nanocomposites (HGMNCs) is higher at higher temperatures than room temperature. The prepared HGMNCs are also subjected to hyperthermia (cancer therapy) studies. - Highlights: • We have developed temperature responsive hydrogel magnetic nanocomposites. • Addition of AMPS monomer to this magnetic hydrogel enhances the temperature sensitivity to 40–43 °C. • Similarly the sulfonic groups present in the AMPS units enhances the swelling ratio of magnetic hydrogels. • AMPS acts as good stabilizing agent for nanoparticles in the magnetic nanogel.

  15. Database of Nucleon-Nucleon Scattering Cross Sections by Stochastic Simulation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A database of nucleon-nucleon elastic differential and total cross sections will be generated by stochastic simulation of the quantum Liouville equation in the...

  16. Chiral nucleon-nucleon forces in nuclear structure calculations

    Directory of Open Access Journals (Sweden)

    Coraggio L.

    2016-01-01

    Full Text Available Realistic nuclear potentials, derived within chiral perturbation theory, are a major breakthrough in modern nuclear structure theory, since they provide a direct link between nuclear physics and its underlying theory, namely the QCD. As a matter of fact, chiral potentials are tailored on the low-energy regime of nuclear structure physics, and chiral perturbation theory provides on the same footing two-nucleon forces as well as many-body ones. This feature fits well with modern advances in ab-initio methods and realistic shell-model. Here, we will review recent nuclear structure calculations, based on realistic chiral potentials, for both finite nuclei and infinite nuclear matter.

  17. On the resonance structure in nucleon-nucleon scattering

    Science.gov (United States)

    Kloet, W. M.; Tjon, J. A.

    1981-10-01

    A possible explanation of resonance-like structure in 1D 2 and 3F 3 proton-proton phase parameters at medium energy is suggested by the analysis of an exactly soluble coupled channel model. Looping in the Argand plot is mainly due to the nucleon-delta branch cut. This effect is already present in the NΔ box diagram, but is modified by higher order multiple scattering. Poles occur close to the NΔ branch point and originate from left-hand singularities in the unphysical sheet.

  18. Separation of Uranium by an Extractant Encapsulated Magnetic Alginate Gels

    Science.gov (United States)

    Portakal, Z.; Gok, C.; Aytas, S.

    The aim of this work is to prepare environmentally friendly and practically applicable alginate magnetic biopolymers encapsulated tri-n-butyl phosphate (TBP) for the removal uranium ions. Some important process parameters such as initial pH, initial U(VI) concentration, adsorbent dosage, time, temperature and sorption isotherms for uranium uptake were studied and the thermodynamic parameters for U(VI) were determined.

  19. Geometric Model Extraction from Magnetic Resonance Volume Data

    OpenAIRE

    Laidlaw, David H.

    1995-01-01

    This thesis presents a computational framework and new algorithms for creating geometric models and images of physical objects. Our framework combines magnetic resonance imaging (MRI) research with image processing and volume visualization. One focus is feedback of requirements from later stages of the framework to earlier ones. Within the framework we measure physical objects yielding vector-valued MRI volume datasets. We process these datasets to identify different materials, and from the c...

  20. Greener synthesis of magnetite nanoparticles using green tea extract and their magnetic properties

    Science.gov (United States)

    Karade, V. C.; Waifalkar, P. P.; Dongle, T. D.; Sahoo, Subasa C.; Kollu, P.; Patil, P. S.; Patil, P. B.

    2017-09-01

    The facile green synthesis method has been employed for the synthesis of biocompatible Fe3O4 magnetic nanoparticles (MNPs) using green tea extract. The effective reduction of ferric ions (Fe3+) were done using an aqueous green tea extract where it acts as reducing as well as capping agent. The effect of iron precursor to green tea extract ratio and reaction temperature was studied. The MNPs were characterized by x-ray diffraction, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, dynamic light scattering and vibrating sample magnetometer. It was observed that the reaction temperature strongly affects the magnetic and structural properties of MNPs. The magnetic measurements study showed that Fe3O4 MNPs are superparamagnetic at 300 K, while at 60 K have ferromagnetic as well as superparamagnetic contributions.

  1. Magnetism of elementary particles

    CERN Document Server

    Vonsovsky, S V

    1975-01-01

    Spin magnetic moment of the electron ; magnetism of the atomic electron shell ; magnetism of nucleons (protons and neutrons) and atomic nuclei ; anomalous magnetic moments of elementary particles ; the magnetic monopole ; non-linear quantum-electrodynamic effects in a magnetic field.

  2. Hard probes of short-range nucleon-nucleon correlations

    Energy Technology Data Exchange (ETDEWEB)

    J. Arrington, D. W. Higinbotham, G. Rosner, M. Sargsian

    2012-10-01

    The strong interaction of nucleons at short distances leads to a high-momentum component to the nuclear wave function, associated with short-range correlations between nucleons. These short-range, high-momentum structures in nuclei are one of the least well understood aspects of nuclear matter, relating to strength outside of the typical mean-field approaches to calculating the structure of nuclei. While it is difficult to study these short-range components, significant progress has been made over the last decade in determining how to cleanly isolate short-range correlations in nuclei. We have moved from asking if such structures exist, to mapping out their strength in nuclei and studying their microscopic structure. A combination of several different measurements, made possible by high-luminosity and high-energy accelerators, coupled with an improved understanding of the reaction mechanism issues involved in studying these structures, has led to significant progress, and provided significant new information on the nature of these small, highly-excited structures in nuclei. We review the general issues related to short-range correlations, survey recent experiments aimed at probing these short-range structures, and lay out future possibilities to further these studies.

  3. The nucleon as a test case to calculate vector-isovector form factors at low energies

    Science.gov (United States)

    Leupold, Stefan

    2018-01-01

    Extending a recent suggestion for hyperon form factors to the nucleon case, dispersion theory is used to relate the low-energy vector-isovector form factors of the nucleon to the pion vector form factor. The additionally required input, i.e. the pion-nucleon scattering amplitudes are determined from relativistic next-to-leading-order (NLO) baryon chiral perturbation theory including the nucleons and optionally the Delta baryons. Two methods to include pion rescattering are compared: a) solving the Muskhelishvili-Omnès (MO) equation and b) using an N/D approach. It turns out that the results differ strongly from each other. Furthermore the results are compared to a fully dispersive calculation of the (subthreshold) pion-nucleon amplitudes based on Roy-Steiner (RS) equations. In full agreement with the findings from the hyperon sector it turns out that the inclusion of Delta baryons is not an option but a necessity to obtain reasonable results. The magnetic isovector form factor depends strongly on a low-energy constant of the NLO Lagrangian. If it is adjusted such that the corresponding magnetic radius is reproduced, then the results for the corresponding pion-nucleon scattering amplitude (based on the MO equation) agree very well with the RS results. Also in the electric sector the Delta degrees of freedom are needed to obtain the correct order of magnitude for the isovector charge and the corresponding electric radius. Yet quantitative agreement is not achieved. If the subtraction constant that appears in the solution of the MO equation is not taken from nucleon+Delta chiral perturbation theory but adjusted such that the electric radius is reproduced, then one obtains also in this sector a pion-nucleon scattering amplitude that agrees well with the RS results.

  4. Selective extraction of berberine from Cortex Phellodendri using polydopamine-coated magnetic nanoparticles.

    Science.gov (United States)

    Shi, Hai-Li; Peng, Shu-Lin; Sun, Jun; Liu, Yi-Ming; Zhu, Yuan-Ting; Qing, Lin-Sen; Liao, Xun

    2014-03-01

    A new extraction agent featuring dopamine self-polymerized on magnetic Fe3 O4 nanoparticles has been successfully synthesized and evaluated for the SPE of berberine from the extract of the traditional Chinese medicinal plant, Cortex Phellodendri. The nanoparticles prepared possessed a core-shell structure and showed super-paramagnetism. It was found that these polydopamine-coated nanoparticles exhibited strong and selective adsorption for berberine. Among the chemical components present in C. Phellodendri, only berberine was adsorbed by the nanoparticles and extracted by a following SPE procedure. Various conditions such as the amount of polydopamine-coated nanoparticles, desorption solvent, desorption time and equilibrium time were optimized for the SPE of berberine. The purity of berberine extracted from C. Phellodendri was determined to be as high as 91.3% compared with that of 9.5% in the extract. The established SPE protocol combined advantages of highly selective enrichment with easy magnetic separation, and proved to be a facile efficient procedure for the isolation of berberine. Further, the prepared polydopamine-coated magnetic nanoparticles could be reused for multiple times, reducing operational cost. The applicability and reliability of the developed SPE method were demonstrated by isolating berberine from three different C. Phellodendri extracts. Recoveries of 85.4-111.2% were obtained with relative standard deviations ranging from 0.27-2.05%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. 180th International School of Physics "Enrico Fermi" : Three-dimensional Partonic Stucture of the Nucleon

    CERN Document Server

    Avakian, H; Hasch, D; Schweitzer, P

    2012-01-01

    The three-dimensional nucleon structure is central to many theoretical and experimental activities, and research in this field has seen many advances in the last two decades, addressing fundamental questions such as the orbital motion of quarks and gluons inside the nucleons, their spatial distribution, and the correlation between spin and intrinsic motion. A real three-dimensional imaging of the nucleon as a composite object, both in momentum and coordinate space, is slowly emerging. This book presents lectures and seminars from the Enrico Fermi School: Three-Dimensional Partonic Structure of the Nucleon, held in Varenna, Italy, in June and July 2011. The topics covered include: partonic distributions, fragmentation functions and factorization in QCD; theory of transverse momentum dependent partonic distributions (TMDs) and generalized partonic distributions (GPDs); experimental methods in studies of hard scattering processes; extraction of TMDs and GPDs from data; analysis tools for azimuthal asymmetries; ...

  6. Radial Dependence of the Nucleon Effective Mass in B sup 1 sup 0

    CERN Document Server

    Bever, L J D; Hicks, R; Jager, K D; Kelly, J; Lapikas, L; Miskimen, R; Neck, D V; Peterson, G; Steenhoven, G; Vries, H D

    1998-01-01

    The dynamic properties of the atomic nucleus depend strongly on correlations between the nucleons. We present a combined analysis of inelastic electron-scattering data and electron-induced proton knockout measurements in an effort to obtain phenomenological information on nucleon-nucleon correlations. Our results indicate that the ration of radial wave functions extracted from precise B sup 1 sup 0 (e,e') and B sup 1 sup 0 (e, e'p) measurements evolve from an interior depression for small Em, characteristic of short-range correlations, to a surface-peaked enhancement for larger Em, characteristic of long-range correlations. This observation can be interpreted in terms of the nucleon effective mass.

  7. Magnetic graphene oxide modified by imidazole-based ionic liquids for the magnetic-based solid-phase extraction of polysaccharides from brown alga.

    Science.gov (United States)

    Wang, Xiaoqin; Li, Guizhen; Row, Kyung Ho

    2017-08-01

    Magnetic graphene oxide was modified by four imidazole-based ionic liquids to synthesize materials for the extraction of polysaccharides by magnetic solid-phase extraction. Fucoidan and laminarin were chosen as the representative polysaccharides owing to their excellent pharmaceutical value and availability. Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, and thermogravimetric analysis were applied to characterize the synthesized materials. Single-factor experiments showed that the extraction efficiency of polysaccharides was affected by the amount of ionic liquids for modification, solid-liquid ratio of brown alga and ethanol, the stirring time of brown alga and ionic liquid-modified magnetic graphene oxide materials, and amount of 1-(3-aminopropyl)imidazole chloride modified magnetic graphene oxide materials added to the brown alga sample solution. The results indicated that 1-(3-aminopropyl)imidazole chloride modified magnetic graphene oxide possessed better extraction ability than graphene oxide, magnetic graphene oxide, and other three ionic-liquid-modified magnetic graphene oxide materials. The highest extraction recoveries of fucoidan and laminarin extracted by 1-(3-aminopropyl)imidazole chloride modified magnetic graphene oxide were 93.3 and 87.2%, respectively. In addition, solid materials could be separated and reused easily owing to their magnetic properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Dataset of plasmid DNA extraction using different magnetic nanoparticles (MNPs

    Directory of Open Access Journals (Sweden)

    H. Rahnama

    2016-12-01

    MNPs were characterized by energy dispersive spectroscopy (EDS and transmission electron microscopy (TEM. Finally, the overall efficiency of different MNPs (Fe3O4, Fe3O4/SiO2, Fe3O4/SiO2/TiO2 in plasmid DNA isolation was compared using gel electrophoresis analysis. The data supplied in this article supports the accompanying publication “Comparative study of three magnetic nano-particles (FeSO4, FeSO4/SiO2, FeSO4/SiO2/TiO2 in plasmid DNA extraction” (H. Rahnama, A. Sattarzadeh, F. Kazemi, N. Ahmadi, F. Sanjarian, Z. Zand, 2016 [1].

  9. Nucleon form factors, generalized parton distributions and quark angular momentum

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, Markus [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kroll, Peter [Bergische Univ., Wuppertal (Germany). Fachbereich Physik; Regensburg Univ. (Germany). Institut fuer Theoretische Physik

    2013-02-15

    We extract the individual contributions from u and d quarks to the Dirac and Pauli form factors of the proton, after a critical examination of the available measurements of electromagnetic nucleon form factors. From this data we determine generalized parton distributions for valence quarks, assuming a particular form for their functional dependence. The result allows us to study various aspects of nucleon structure in the valence region. In particular, we evaluate Ji's sum rule and estimate the total angular momentum carried by valence quarks at the scale {mu}=2 GeV to be J{sup u}{sub v}=0.230{sup +0.009}{sub -0.024} and J{sup d}{sub v}=-0.004{sup +0.010}{sub -0.016}.

  10. The cosmic-ray He-3/He-4 ratio from 200 MeV per nucleon(-1) to 3.7 GeV per nucleon(-1)

    DEFF Research Database (Denmark)

    Reimer, O.; Menn, W.; Hof, M.

    1998-01-01

    The abundances of cosmic-ray helium isotopes between 0.2 and 3.7 GeV nucleon(-1) were measured by the Isotope Matter Antimatter Experiment (IMAX) during a flight from Lynn Lake, Manitoba, Canada on 1992 July 16-17. The IMAX balloon-borne magnetic spectrometer realized a direct measurement...

  11. Quark model for kaon nucleon scattering

    Indian Academy of Sciences (India)

    Abstract. Kaon nucleon elastic scattering is studied using chiral SU(3) quark model including antiquarks. Parameters of the present model are essentially based on nucleon–nucleon and nucleon– hyperon interactions. The mass of the scalar meson σ is taken as 635 MeV. Using this model, the phase shifts of the S and P ...

  12. Cosmic Ray Deuterium from 0.2 to 3.0 GeV/nucleon

    DEFF Research Database (Denmark)

    Davis, A.J.; Labrador, A.W.; Mewaldt, R.A.

    1996-01-01

    The abundances of cosmic ray protons and deuterium between 0.2 and 3.0 GeV/nucleon were measured by the IMAX balloon--borne magnet spectrometer during a flight in July, 1992. These isotope measurements extend to significantly higher energies than have previously been achieved. A high--resolution ......The abundances of cosmic ray protons and deuterium between 0.2 and 3.0 GeV/nucleon were measured by the IMAX balloon--borne magnet spectrometer during a flight in July, 1992. These isotope measurements extend to significantly higher energies than have previously been achieved. A high...

  13. Liquid metal extraction of Nd from NdFeB magnet scrap

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yanchen [Iowa State Univ., Ames, IA (United States)

    1999-12-10

    This research involves using molten magnesium (Mg) to remove neodymium (Nd) from NdFeB magnet scrap by diffusion. The results show that liquid metal extraction of Nd may be a viable and inexpensive method for recovering the expensive rare earth element Nd for use in Mg castings.

  14. The Septum Magnet System of the New Fast Extraction Channel of the SPS at CERN

    CERN Document Server

    Balhan, B; Rizzo, A; Weterings, W

    2004-01-01

    In the Long Straight Section LSS4 of the Super Proton Synchrotron (SPS) at CERN, a new fast extraction system has been installed in order to extract the beam to ring 2 of the Large Hadron Collider (LHC) and the CERN Neutrino to Gran Sasso facility (CNGS). The system consists of horizontal closed orbit bumper magnets, extraction kicker magnets, enlarged aperture quadrupoles and six conventional DC electromagnetic septum magnets (MSE). A protection element (TPSG) has been placed immediately upstream of the first septum coil. The septum magnets and TPSG are mounted on a single mobile retractable support girder. The MSE septa are connected by a so-called plug-in system to a rigid water-cooled bus-bar, powered by water-cooled cables. The whole system is kept at the required vacuum pressure by ion pumps attached to separate pumping modules. In this note we present the design features and parameters of the MSE septum magnets, describe the function of the related main equipment elements, briefly report on the control...

  15. Nanosized Difunctional Photo Responsive Magnetic Imprinting Polymer for Electrochemically Monitored Light-Driven Paracetamol Extraction.

    Science.gov (United States)

    Wei, Yubo; Zeng, Qiang; Bai, Silan; Wang, Min; Wang, Lishi

    2017-12-20

    Herein, a novel photoresponsive magnetic electrochemical imprinting sensor for the selective extraction of paracetamol from biological samples was designed. In particular, nanosized photoresponsive molecular imprinted polymers were prepared on the surface of magnetic Fe3O4 nanoparticles through living radical polymerization of azobenzene. The introduction of a magnetic-controlled glassy carbon electrode makes the immobilization and removal of nanosized photoresponsive molecular imprinted polymers on the magnetic-controlled glassy carbon electrode surface facilely operational. With the photoresponsive property, the sensor undergoes reversible release and uptake of paracetamol upon alternative irradiation at 365 and 440 nm basing on a configurational change of azobenzene monomer in the photoresponsive molecular imprinted polymers receptor sites. Simultaneously, these processes are monitored by the photoresponsive changes of electrochemical signal from paracetamol. Two linear ranges from 0.001 to 0.7 mmol L-1 (R2 = 0.96) and 0.7 to 7 mmol L-1 (R2 = 0.95) for paracetamol determination were obtained with a quantification limit of 0.000 86 mmol L-1 and a detection limit of 0.000 43 mmol L-1. The recoveries of paracetamol in the urine as determined by photoresponsive molecular imprinted polymers extraction were varied between 87.5% and 93.3%. As a consequence, combining photocontrolled selective extraction, interfacial stability from magnetic adsorption, and specifically electrochemical response, the photoresponsive molecular imprinted polymers sensor shows significant advantages for simultaneous separation, enrichment, and detection of trace paracetamol in biological samples.

  16. Measurement of the strange quark content of nucleon: G{sup 0} experiment; Mesure du contenu etrange du nucleon: experience G{sup 0}

    Energy Technology Data Exchange (ETDEWEB)

    Batigne, G

    2003-12-01

    The G{sup 0} project is a parity violation experiment dedicated to the measurement of the proton weak and axial form factors by means of electron-proton scattering. Combining these weak form factors with the electromagnetic ones makes possible the extraction of the contribution of strange quarks to the charge and magnetization distribution in the nucleon. This thesis presents the strategy used for the G{sup 0} experiment, the different subsystems and the first results from its engineering run. The counting rate asymmetries, at the order of 10-5, are measured over a large range in transferred momentum (Q{sup 2} = 0.1 to 1 (GeV/c){sup 2}) with expected precision at the level of 10{sup -7}. A deadtime correction program has been developed which allows to correct 90% of the counting losses and to reduce associated false asymmetries at the level of 10-8. A method has been defined to extract the measured values of Q{sup 2} with a precision of 1%. The first preliminary results of G{sup 0} on parity violation asymmetries are also shown. (author)

  17. Two-Pion Production in Nucleon-Nucleon Collisions

    Science.gov (United States)

    Clement, Heinz; Brodowski, W.; Bilger, R.; Calén, H.; Clement, H.; Ekström, C.; Fransson, K.; Greiff, J.; Häggström, S.; Höistad, B.; Johanson, J.; Johansson, A.; Johansson, T.; Kilian, K.; Kullander, S.; Kupść, A.; Marciniewski, P.; Morosov, B.; Oelert, W.; Pätzold, J.; Ruber, R. J. M. Y.; Schepkin, M.; Scobel, W.; Seluzhenkov, I.; Stepaniak, J.; Sukhanov, A.; Turowiecki, A.; Wagner, G. J.; Wilhelmi, Z.; Zabierowski, J.; Zlomanczuk, J.

    2003-01-01

    Measurements of the two-pion production near threshold have been carried out at CELSIUS with the PROMICE-WASA detector for the channels pp → pnπ+π0, pp → ppπ0π0 and pp → ppπ+π-. For the latter channel the first exclusive data of solid statistics have been obtained. Within a conventional interpretation of the reaction mechanism they reveal pp → pp*(1440) → ppσ → pp(π+π-)I=ℓ=0 as the dominant process as well as significant contributions from p*(1440) → Δπ → p(π+π-)I=ℓ=0. The observed anisotropy in the proton angular distribution is consistent with heavy-meson exchange between the colliding nucleons.

  18. Perfusion information extracted from resting state functional magnetic resonance imaging.

    Science.gov (United States)

    Tong, Yunjie; Lindsey, Kimberly P; Hocke, Lia M; Vitaliano, Gordana; Mintzopoulos, Dionyssios; Frederick, Blaise deB

    2017-02-01

    It is widely known that blood oxygenation level dependent (BOLD) contrast in functional magnetic resonance imaging (fMRI) is an indirect measure for neuronal activations through neurovascular coupling. The BOLD signal is also influenced by many non-neuronal physiological fluctuations. In previous resting state (RS) fMRI studies, we have identified a moving systemic low frequency oscillation (sLFO) in BOLD signal and were able to track its passage through the brain. We hypothesized that this seemingly intrinsic signal moves with the blood, and therefore, its dynamic patterns represent cerebral blood flow. In this study, we tested this hypothesis by performing Dynamic Susceptibility Contrast (DSC) MRI scans (i.e. bolus tracking) following the RS scans on eight healthy subjects. The dynamic patterns of sLFO derived from RS data were compared with the bolus flow visually and quantitatively. We found that the flow of sLFO derived from RS fMRI does to a large extent represent the blood flow measured with DSC. The small differences, we hypothesize, are largely due to the difference between the methods in their sensitivity to different vessel types. We conclude that the flow of sLFO in RS visualized by our time delay method represents the blood flow in the capillaries and veins in the brain.

  19. Magnetic solid-phase extraction using carbon nanotubes as sorbents: a review.

    Science.gov (United States)

    Herrero-Latorre, C; Barciela-García, J; García-Martín, S; Peña-Crecente, R M; Otárola-Jiménez, J

    2015-09-10

    Magnetic solid-phase extraction (M-SPE) is a procedure based on the use of magnetic sorbents for the separation and preconcentration of different organic and inorganic analytes from large sample volumes. The magnetic sorbent is added to the sample solution and the target analyte is adsorbed onto the surface of the magnetic sorbent particles (M-SPs). Analyte-M-SPs are separated from the sample solution by applying an external magnetic field and, after elution with the appropriate solvent, the recovered analyte is analyzed. This approach has several advantages over traditional solid phase extraction as it avoids time-consuming and tedious on-column SPE procedures and it provides a rapid and simple analyte separation that avoids the need for centrifugation or filtration steps. As a consequence, in the past few years a great deal of research has been focused on M-SPE, including the development of new sorbents and novel automation strategies. In recent years, the use of magnetic carbon nanotubes (M-CNTs) as a sorption substrate in M-SPE has become an active area of research. These materials have exceptional mechanical, electrical, optical and magnetic properties and they also have an extremely large surface area and varied possibilities for functionalization. This review covers the synthesis of M-CNTs and the different approaches for the use of these compounds in M-SPE. The performance, general characteristics and applications of M-SPE based on magnetic carbon nanotubes for organic and inorganic analysis have been evaluated on the basis of more than 110 references. Finally, some important challenges with respect the use of magnetic carbon nanotubes in M-SPE are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Magnetic headspace adsorptive extraction of chlorobenzenes prior to thermal desorption gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Vidal, Lorena, E-mail: lorena.vidal@ua.es [Department of Analytical Chemistry, Nutrition and Food Sciences and University Institute of Materials, University of Alicante, P.O. Box 99, E-03080, Alicante (Spain); Ahmadi, Mazaher [Faculty of Chemistry, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Fernández, Elena [Department of Analytical Chemistry, Nutrition and Food Sciences and University Institute of Materials, University of Alicante, P.O. Box 99, E-03080, Alicante (Spain); Madrakian, Tayyebeh [Faculty of Chemistry, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Canals, Antonio, E-mail: a.canals@ua.es [Department of Analytical Chemistry, Nutrition and Food Sciences and University Institute of Materials, University of Alicante, P.O. Box 99, E-03080, Alicante (Spain)

    2017-06-08

    This study presents a new, user-friendly, cost-effective and portable headspace solid-phase extraction technique based on graphene oxide decorated with iron oxide magnetic nanoparticles as sorbent, located on one end of a small neodymium magnet. Hence, the new headspace solid-phase extraction technique has been called Magnetic Headspace Adsorptive Extraction (Mag-HSAE). In order to assess Mag-HSAE technique applicability to model analytes, some chlorobenzenes were extracted from water samples prior to gas chromatography-mass spectrometry determination. A multivariate approach was employed to optimize the experimental parameters affecting Mag-HSAE. The method was evaluated under optimized extraction conditions (i.e., sample volume, 20 mL; extraction time, 30 min; sorbent amount, 10 mg; stirring speed, 1500 rpm, and ionic strength, non-significant), obtaining a linear response from 0.5 to 100 ng L{sup −1} for 1,3-DCB, 1,4-DCB, 1,2-DCB, 1,3,5-TCB, 1,2,4-TCB and 1,2,3-TCB; from 0.5 to 75 ng L{sup −1} for 1,2,4,5-TeCB, and PeCB; and from 1 to 75 ng L{sup −1} for 1,2,3,4-TeCB. The repeatability of the proposed method was evaluated at 10 ng L{sup −1} and 50 ng L{sup −1} spiking levels, and coefficients of variation ranged between 1.5 and 9.5% (n = 5). Limits of detection values were found between 93 and 301 pg L{sup −1}. Finally, tap, mineral and effluent water were selected as real water samples to assess method applicability. Relative recoveries varied between 86 and 110% showing negligible matrix effects. - Highlights: • A new extraction technique named Magnetic Headspace Adsorptive Extraction is presented. • Graphene oxide/iron oxide composite deposited on a neodymiun magnet as sorbent. • Sorbent of low cost, rapid and simple synthesis, easy manipulation and portability options. • Fast and efficient extraction and sensitive determination of chlorobenzenes in water samples.

  1. Headspace single drop microextraction versus dispersive liquid-liquid microextraction using magnetic ionic liquid extraction solvents.

    Science.gov (United States)

    An, Jiwoo; Rahn, Kira L; Anderson, Jared L

    2017-05-15

    A headspace single drop microextraction (HS-SDME) method and a dispersive liquid-liquid microextraction (DLLME) method were developed using two tetrachloromanganate ([MnCl42-])-based magnetic ionic liquids (MIL) as extraction solvents for the determination of twelve aromatic compounds, including four polyaromatic hydrocarbons, by reversed phase high-performance liquid chromatography (HPLC). The analytical performance of the developed HS-SDME method was compared to the DLLME approach employing the same MILs. In the HS-SDME approach, the magnetic field generated by the magnet was exploited to suspend the MIL solvent from the tip of a rod magnet. The utilization of MILs in HS-SDME resulted in a highly stable microdroplet under elevated temperatures and long extraction times, overcoming a common challenge encountered in traditional SDME approaches of droplet instability. The low UV absorbance of the [MnCl42-]-based MILs permitted direct analysis of the analyte enriched extraction solvent by HPLC. In HS-SDME, the effects of ionic strength of the sample solution, temperature of the extraction system, extraction time, stir rate, and headspace volume on extraction efficiencies were examined. Coefficients of determination (R2) ranged from 0.994 to 0.999 and limits of detection (LODs) varied from 0.04 to 1.0μgL-1 with relative recoveries from lake water ranging from 70.2% to 109.6%. For the DLLME method, parameters including disperser solvent type and volume, ionic strength of the sample solution, mass of extraction solvent, and extraction time were studied and optimized. Coefficients of determination for the DLLME method varied from 0.997 to 0.999 with LODs ranging from 0.05 to 1.0μgL-1. Relative recoveries from lake water samples ranged from 68.7% to 104.5%. Overall, the DLLME approach permitted faster extraction times and higher enrichment factors for analytes with low vapor pressure whereas the HS-SDME approach exhibited better extraction efficiencies for analytes with

  2. Pairing gaps in nucleonic superfluids

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J.M.C. (McDonnell Center for the Space Sciences and Dept. of Physics, Washington Univ., St. Louis, MO (United States)); Clark, J.W. (McDonnell Center for the Space Sciences and Dept. of Physics, Washington Univ., St. Louis, MO (United States)); Dave, R.D. (McDonnell Center for the Space Sciences and Dept. of Physics, Washington Univ., St. Louis, MO (United States)); Khodel, V.V. (McDonnell Center for the Space Sciences and Dept. of Physics, Washington Univ., St. Louis, MO (United States))

    1993-04-05

    Singlet S-wave nucleonic superfluids are studied within a microscopic many-body theory that incorporates explicit spatial correlations due to strong short-range repulsive forces as well as the momentum-space pairing correlations of BCS theory. The theory is formulated within the method of correlated basis functions (CBF). Within this scheme, there results a nonlinear problem for the superfluid energy gap that is identical in form to the gap problem of conventional BCS theory. However, the input single-particle energies and pairing matrix elements are dressed by the short-range spatial correlations and accordingly incorporate an important class of medium corrections. The effective pairing force of the theory is finite even if the bare two-nucleon potential contains an infinitely hard core; both the pairing matrix elements and single-particle energies are to be constructed from normal-state CBF matrix elements and may be evaluated by cluster-expansion techniques. The theory is explicated and applied at a variational level that is equivalent to the leading order of a CBF superstate perturbation theory. New results are presented for the [sup 1]S[sub 0] pairing gap [Delta][sub kF] in pure neutron matter at densities relevant to the inner crust of a neutron star, based on a simplified version of the Reid soft-core interaction and spin-dependent spatial correlations optimized in the correlated normal state. Careful considering is given to the treatment of the gap equation at large intermediate-state momenta. The variational gap function evaluated at the Fermi surface, [Delta][sub F], is found to be larger than predicted in earlier work. Estimates of the suppression of the gap due to polarization processes (and other particle-particle and hole-irreducible medium effects of higher order within CBF superstate perturbation theory) yield values of [Delta][sub kF].

  3. Extraction of DNA by magnetic ionic liquids: tunable solvents for rapid and selective DNA analysis.

    Science.gov (United States)

    Clark, Kevin D; Nacham, Omprakash; Yu, Honglian; Li, Tianhao; Yamsek, Melissa M; Ronning, Donald R; Anderson, Jared L

    2015-02-03

    DNA extraction represents a significant bottleneck in nucleic acid analysis. In this study, hydrophobic magnetic ionic liquids (MILs) were synthesized and employed as solvents for the rapid and efficient extraction of DNA from aqueous solution. The DNA-enriched microdroplets were manipulated by application of a magnetic field. The three MILs examined in this study exhibited unique DNA extraction capabilities when applied toward a variety of DNA samples and matrices. High extraction efficiencies were obtained for smaller single-stranded and double-stranded DNA using the benzyltrioctylammonium bromotrichloroferrate(III) ([(C8)3BnN(+)][FeCl3Br(-)]) MIL, while the dicationic 1,12-di(3-hexadecylbenzimidazolium)dodecane bis[(trifluoromethyl)sulfonyl]imide bromotrichloroferrate(III) ([(C16BnIM)2C12(2+)][NTf2(-), FeCl3Br(-)]) MIL produced higher extraction efficiencies for larger DNA molecules. The MIL-based method was also employed for the extraction of DNA from a complex matrix containing albumin, revealing a competitive extraction behavior for the trihexyl(tetradecyl)phosphonium tetrachloroferrate(III) ([P6,6,6,14(+)][FeCl4(-)]) MIL in contrast to the [(C8)3BnN(+)][FeCl3Br(-)] MIL, which resulted in significantly less coextraction of albumin. The MIL-DNA method was employed for the extraction of plasmid DNA from bacterial cell lysate. DNA of sufficient quality and quantity for polymerase chain reaction (PCR) amplification was recovered from the MIL extraction phase, demonstrating the feasibility of MIL-based DNA sample preparation prior to downstream analysis.

  4. Quick and selective extraction of Z-ligustilide from Angelica sinensis using magnetic multiwalled carbon nanotubes.

    Science.gov (United States)

    Zeng, Qiong; Jia, Yan-Wei; Xu, Pei-Li; Xiao, Meng-Wei; Liu, Yi-Ming; Peng, Shu-Lin; Liao, Xun

    2015-12-01

    A facile and highly efficient magnetic solid-phase extraction method has been developed for Z-ligustilide, the major therapeutic agent in Angelica sinensis. The solid-phase adsorbent material used was prepared by conjugating carbon nanotubes with magnetic Fe3 O4 nanoparticles via a hydrothermal reaction. The magnetic material showed a high affinity toward Z-ligustilide due to the π-π stacking interaction between the carbon nanotubes and Z-ligustilide, allowing a quick and selective exaction of Z-ligustilide from complex sample matrices. Factors influencing the magnetic solid-phase extraction such as the amount of the added adsorbent, adsorption and desorption time, and desorption solvent, were investigated. Due to its high extraction efficiency, this method was proved highly useful for sample cleanup/enrichment in quantitative high-performance liquid chromatography analysis. The proposed method had a linear calibration curve (R(2) = 0.9983) over the concentration between 4 ng/mL and 200 μg/mL Z-ligustilide. The accuracy of the method was determined by the recovery, which was from 92.07 to 104.02%, with the relative standard deviations >4.51%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Strange Nucleon Form Factors from ep and vp Elastic Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Pate, S.F. [Physics Department, New Mexico State University, Las Cruces NM 88003 (United States)]. e-mail: pate@nmsu.edu

    2007-12-15

    The recent parity-violating ep forward-scattering elastic asymmetry data from Jefferson Lab (HAPPEx and G0), when combined with the vp elastic cross section data from Brookhaven (E734), permit an extraction of the strangeness contribution to the vector and axial nucleon form factors for momentum transfers in the range 0.45 < Q{sup 2} < 1.0 GeV{sup 2}. These results, combined with the recent determination of the strange vector form factors at Q{sup 2} = 0.1 GeV{sup 2} (SAMPLE, HAPPEx, PVA4, G0) have been interpreted in terms of uudss{sup -} configurations very different from the kaon-loop configurations usually associated with strangeness in the nucleon. New experiments are being proposed to improve the state of our knowledge of the vp elastic cross section -- these new experiments will push the range of Q{sup 2} to much lower values, and greatly increase the precision of the vp elastic data. One outcome of this can be a measurement of the strangeness contribution to the nucleon spin, {delta}s. Nuclear targets (e.g. C or Ar) are to be used in these neutrino experiments, and so a deep understanding of the nuclear physics, particularly in regard to final state effects, is needed before the potential of these precision experiments can be fully realized. (Author)

  6. Applications of magnetic surface imprinted materials for solid phase extraction of levofloxacin in serum samples.

    Science.gov (United States)

    Xiao, Deli; Wang, Cuixia; Dai, Hao; Peng, Jun; He, Jia; Zhang, Kai; Kong, Sumei; Qiu, Panzi; He, Hua

    2015-05-01

    In this work, molecularly imprinted magnetic carbon nanotubes (MCNTs@MIPs) was prepared with surface imprinting technique for extraction of levofloxacin in serum samples. The preparation of molecularly imprinted polymers (MIPs) used levofloxacin as template, methacrylic acid as functional monomer, and ethylene glycol dimethacrylate as cross-linker, and the magnetic carbon nanotubes (MCNTs) was synthesized by solvothermal method. The prepared polymers not only can be separated and collected easily by an external magnetic, but also exhibited high specific surface area and high selectivity to template molecules. Kinetic adsorption and static adsorption capacity investigations indicated that the synthesized MCNTs@MIPs had excellent recognition towards levofloxacin. Furthermore, magnetic solid phase extraction (MSPE) using the prepared MCNTs@MIPs as sorbent was then investigated, and an efficient sample cleanup was obtained with recoveries ranged from 78.7 ± 4.8 % to 83.4 ± 4.1%. In addition, several parameters, including the pH of samples, the amount of MCNTs@MIPs, the adsorption and desorption times, and the eluent, were investigated to obtain optimal extraction efficiency. Under the optimal extraction conditions, the stability of the polymer was also evaluated, and the average recovery reduced less than 7.6% after 5 cycles. MCNTs@MIPs successfully applied in the preconcentration and determination of levofloxacin in serum sample suggested that the MSPE method based on the novel polymers could be a promising alternative for selective and efficient extraction of trace amounts of pharmaceutical substances in bio-matrix samples. Copyright © 2015 John Wiley & Sons, Ltd.

  7. Confining quark condensate model of the nucleon.

    Energy Technology Data Exchange (ETDEWEB)

    Frank, Michael; Tandy, Peter

    1992-07-01

    We obtain a mean-field solution for the nucleon as a quark-meson soliton obtained from the action of the global color-symmetry model of QCD. All dynamics is generated from an effective interaction of quark currents. At the quark-meson level there are two novel features: (1) absolute confinement is produced from the space-time structure of the dynamical self-energy in the vacuum quark propagator; and (2) the related scalar meson field is an extended q-barq composite that couples nonlocally to quarks. The influence of these features upon the nucleon mass contributions and other nucleon properties is presented.

  8. Nucleon wave function from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Warkentin, Nikolaus

    2008-04-15

    In this work we develop a systematic approach to calculate moments of leading-twist and next-to-leading twist baryon distribution amplitudes within lattice QCD. Using two flavours of dynamical clover fermions we determine low moments of nucleon distribution amplitudes as well as constants relevant for proton decay calculations in grand unified theories. The deviations of the leading-twist nucleon distribution amplitude from its asymptotic form, which we obtain, are less pronounced than sometimes claimed in the literature. The results are applied within the light cone sum rule approach to calculate nucleon form factors that are compared with recent experimental data. (orig.)

  9. Efficient inclusion body processing using chemical extraction and high gradient magnetic fishing

    DEFF Research Database (Denmark)

    Heebøll-Nielsen, Anders; Choe, W.S.; Middelberg, A.P.J.

    2003-01-01

    In this study we introduce a radical new approach for the recovery of proteins expressed in the form of inclusion bodies, involving W chemical extraction from the host cells, (ii) adsorptive capture of the target protein onto small magnetic adsorbents, and (iii) subsequent rapid collection...... of the product-loaded supports with the aid of high gradient magnetic fields. The manufacture and testing of two types of micron-sized nonporous superparamagnetic metal chelator particles derivatized with iminodiacetic acid is described. In small-scale adsorption studies conducted with a hexahistidine tagged...

  10. Magnetic headspace adsorptive extraction of chlorobenzenes prior to thermal desorption gas chromatography-mass spectrometry.

    Science.gov (United States)

    Vidal, Lorena; Ahmadi, Mazaher; Fernández, Elena; Madrakian, Tayyebeh; Canals, Antonio

    2017-06-08

    This study presents a new, user-friendly, cost-effective and portable headspace solid-phase extraction technique based on graphene oxide decorated with iron oxide magnetic nanoparticles as sorbent, located on one end of a small neodymium magnet. Hence, the new headspace solid-phase extraction technique has been called Magnetic Headspace Adsorptive Extraction (Mag-HSAE). In order to assess Mag-HSAE technique applicability to model analytes, some chlorobenzenes were extracted from water samples prior to gas chromatography-mass spectrometry determination. A multivariate approach was employed to optimize the experimental parameters affecting Mag-HSAE. The method was evaluated under optimized extraction conditions (i.e., sample volume, 20 mL; extraction time, 30 min; sorbent amount, 10 mg; stirring speed, 1500 rpm, and ionic strength, non-significant), obtaining a linear response from 0.5 to 100 ng L-1 for 1,3-DCB, 1,4-DCB, 1,2-DCB, 1,3,5-TCB, 1,2,4-TCB and 1,2,3-TCB; from 0.5 to 75 ng L-1 for 1,2,4,5-TeCB, and PeCB; and from 1 to 75 ng L-1 for 1,2,3,4-TeCB. The repeatability of the proposed method was evaluated at 10 ng L-1 and 50 ng L-1 spiking levels, and coefficients of variation ranged between 1.5 and 9.5% (n = 5). Limits of detection values were found between 93 and 301 pg L-1. Finally, tap, mineral and effluent water were selected as real water samples to assess method applicability. Relative recoveries varied between 86 and 110% showing negligible matrix effects. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Aptamer-functionalized Fe3 O4 magnetic nanoparticles as a solid-phase extraction adsorbent for the selective extraction of berberine from Cortex phellodendri.

    Science.gov (United States)

    Jiang, Ling-Feng; Chen, Bo-Cheng; Chen, Ben; Li, Xue-Jian; Liao, Hai-Lin; Zhang, Wen-Yan; Wu, Lin

    2017-07-01

    The extraction adsorbent was fabricated by immobilizing the highly specific recognition and binding of aptamer onto the surface of Fe3 O4 magnetic nanoparticles, which not only acted as recognition elements to recognize and capture the target molecule berberine from the extract of Cortex phellodendri, but also could favor the rapid separation and purification of the bound berberine by using an external magnet. The developed solid-phase extraction method in this work was useful for the selective extraction and determination of berberine in Cortex phellodendri extracts. Various conditions such as the amount of aptamer-functionalized Fe3 O4 magnetic nanoparticles, extraction time, temperature, pH value, Mg2+ concentration, elution time and solvent were optimized for the solid-phase extraction of berberine. Under optimal conditions, the purity of berberine extracted from Cortex phellodendri was as high as 98.7% compared with that of 4.85% in the extract, indicating that aptamer-functionalized Fe3 O4 magnetic nanoparticles-based solid-phase extraction method was very effective for berberine enrichment and separation from a complex herb extract. The applicability and reliability of the developed solid-phase extraction method were demonstrated by separating berberine from nine different concentrations of one Cortex phellodendri extract. The relative recoveries of the spiked solutions of all the samples were between 95.4 and 111.3%, with relative standard deviations ranging between 0.57 and 1.85%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Probing the repulsive core of the nucleon-nucleon interaction via the (4)He(e,e'pN) triple-coincidence reaction.

    Science.gov (United States)

    Korover, I; Muangma, N; Hen, O; Shneor, R; Sulkosky, V; Kelleher, A; Gilad, S; Higinbotham, D W; Piasetzky, E; Watson, J W; Wood, S A; Aguilera, P; Ahmed, Z; Albataineh, H; Allada, K; Anderson, B; Anez, D; Aniol, K; Annand, J; Armstrong, W; Arrington, J; Averett, T; Badman, T; Baghdasaryan, H; Bai, X; Beck, A; Beck, S; Bellini, V; Benmokhtar, F; Bertozzi, W; Bittner, J; Boeglin, W; Camsonne, A; Chen, C; Chen, J-P; Chirapatpimol, K; Cisbani, E; Dalton, M M; Daniel, A; Day, D; de Jager, C W; De Leo, R; Deconinck, W; Defurne, M; Flay, D; Fomin, N; Friend, M; Frullani, S; Fuchey, E; Garibaldi, F; Gaskell, D; Gilman, R; Glamazdin, O; Gu, C; Gueye, P; Hamilton, D; Hanretty, C; Hansen, J-O; Hashemi Shabestari, M; Holmstrom, T; Huang, M; Iqbal, S; Jin, G; Kalantarians, N; Kang, H; Khandaker, M; LeRose, J; Leckey, J; Lindgren, R; Long, E; Mammei, J; Margaziotis, D J; Markowitz, P; Marti Jimenez-Arguello, A; Meekins, D; Meziani, Z; Michaels, R; Mihovilovic, M; Monaghan, P; Munoz Camacho, C; Norum, B; Nuruzzaman; Pan, K; Phillips, S; Pomerantz, I; Posik, M; Punjabi, V; Qian, X; Qiang, Y; Qiu, X; Rakhman, A; Reimer, P E; Riordan, S; Ron, G; Rondon-Aramayo, O; Saha, A; Schulte, E; Selvy, L; Shahinyan, A; Sirca, S; Sjoegren, J; Slifer, K; Solvignon, P; Sparveris, N; Subedi, R; Tireman, W; Wang, D; Weinstein, L B; Wojtsekhowski, B; Yan, W; Yaron, I; Ye, Z; Zhan, X; Zhang, J; Zhang, Y; Zhao, B; Zhao, Z; Zheng, X; Zhu, P; Zielinski, R

    2014-07-11

    We studied simultaneously the (4)He(e,e'p), (4)He(e,e'pp), and (4)He(e,e'pn) reactions at Q(2)=2(GeV/c)(2) and x(B)>1, for an (e,e'p) missing-momentum range of 400 to 830  MeV/c. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum, leaving the residual A=2 system at low excitation energy. These data were used to identify two-nucleon short-range correlated pairs and to deduce their isospin structure as a function of missing momentum, in a region where the nucleon-nucleon (NN) force is expected to change from predominantly tensor to repulsive. The abundance of neutron-proton pairs is reduced as the nucleon momentum increases beyond ∼500  MeV/c. The extracted fraction of proton-proton pairs is small and almost independent of the missing momentum. Our data are compared with calculations of two-nucleon momentum distributions in (4)He and discussed in the context of probing the elusive repulsive component of the NN force.

  13. Convergence of the hole-line expansion with modern nucleon-nucleon potentials

    Science.gov (United States)

    Lu, Jia-Jing; Li, Zeng-Hua; Chen, Chong-Yang; Baldo, M.; Schulze, H.-J.

    2017-10-01

    We calculate the three-hole-line contributions to the binding energy of symmetric nuclear matter in the Brueckner-Bethe-Goldstone expansion using various modern nucleon-nucleon potentials of high precision. The relation with the correlation parameter κ =ρ Vcore is examined. In all cases the three-hole-line contributions turn out to be sufficiently small, but no satisfactory saturation is obtained. This means that three-nucleon forces are essential for all considered potentials.

  14. Selective extraction and determination of chlorogenic acid in fruit juices using hydrophilic magnetic imprinted nanoparticles.

    Science.gov (United States)

    Hao, Yi; Gao, Ruixia; Liu, Dechun; He, Gaiyan; Tang, Yuhai; Guo, Zengjun

    2016-06-01

    In this paper, the novel hydrophilic magnetic molecularly imprinted nanoparticles were developed for selective separation and determination of chlorogenic acid in aqueous fruit juices. The polymers were prepared by using amino-functionalized magnetic nanoparticles as carriers, branched polyethyleneimine as functional monomer, and chlorogenic acid as template molecule. Branched polyethyleneimine with abundant active amino groups could react with template sufficiently, and its unique dendritic structure may amplify the number of the imprinted cavities. Meanwhile, it would improve the hydrophilicity of imprinted materials for attaining high extraction efficiency. The resulted polymers exhibit fast kinetics, high adsorption capacity, and favorable selectivity. In addition, the obtained nanoparticles were used as solid-phase extraction sorbents for selective isolation and determination of chlorogenic acid in peach, apple, and grape juices (0.92, 4.21, and 0.75 μg mL(-1), respectively). Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Specification for Injection, Thin extraction and Thick Extraction Septa Magnets of the Synchrotron Accelerator CNA Project

    CERN Document Server

    Borburgh, J; Hourican, M; Metzmacher, K; CERN. Geneva. AB Department

    2003-01-01

    A synchrotron machine, capable to accelerate either light ions or protons, will be the basic instrument of the CNA (Centro Nazionale di Adroterapia), the medical center dedicated to the cancer therapy, that will be built in Italy in the near future. The machine complex consists of one proton-carbon-ion linac that will accelerate the particles to an energy of 7 MeV/u. An injection line will transfer them to the synchrotron ring where the injected particles will be accelerated and extracted with an energy ranging from 60 to 250 MeV for protons and from 120 to 400 MeV/u for carbon ions. Figure 1 shows a preliminary schematic picture of the CNA medical center.

  16. Particle production from off-shell nucleons

    OpenAIRE

    Bozek, P

    1998-01-01

    Particle production in equilibrium and nonequilibrium quantum systems is calculated. The effects of the off-shell propagation of nucleons in medium on the particle production are discussed. Comparision to the semiclassical production rate is given.

  17. Nuclear interaction and quark structure of nucleons

    Energy Technology Data Exchange (ETDEWEB)

    Catara, F. (Ist. Nazionale di Fisica Nucleare, Catania (Italy) Dipt. di Fisica, Univ. Catania (Italy)); Sambataro, M. (Ist. Nazionale di Fisica Nucleare, Catania (Italy))

    1991-12-30

    We discuss a procedure to construct the nucleon image of a quark operator in a non-relativistic approach. The procedure is based on the concept of mapping and establishes a correspondence between a space of three-quark clusters and a space of elementary nucleons. As an example, we search for the nucleon image of a quark hamiltonian proposed by Oka and Yazaki. The nucleon hamiltonian is hermitian, non-local and N-body (if N is the number of clusters under consideration). We construct the two-body term of this hamiltonian and search for a local effective-interaction equivalent in a harmonic-oscillator basis to the quark-derived hamiltonian. (orig.).

  18. Nucleon form factors in the nuclear medium

    Science.gov (United States)

    Park, Chanyong; Lee, Jung Hun

    2018-01-01

    By using the AdS/CFT correspondence, we investigate various form factors between nucleons and mesons in a nuclear medium. In order to describe a nuclear medium holographically, we take into account the thermal charged AdS geometry with an appropriate IR cutoff. After introducing an anomalous dimension as a free parameter, we investigate how the nucleon’s mass is affected by the change of the anomalous dimension. Moreover, we study how the form factors of nucleons rely on the properties of the nuclear medium. We show that in a nuclear medium with different numbers of proton and neutron, the degenerated nucleon form factor in the vacuum is split into four different values depending on the isospin charges of nucleon and meson.

  19. Insights into nucleon structure from parton distributions

    Energy Technology Data Exchange (ETDEWEB)

    Melnitchouk, Wally [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2017-05-01

    We review recent progress in understanding the substructure of the nucleon from global QCD analysis of parton distribution functions (PDFs). New high-precision data onW-boson production in p ¯ p collisions have significantly reduced the uncertainty on the d=u PDF ratio at large values of x, indirectly constraining models of the medium modification of bound nucleons. Drell-Yan data from pp and pd scattering reveal new information on the d¯-u¯ asymmetry, clarifying the role of chiral symmetry breaking in the nucleon. In the strange sector, a new chiral SU(3) analysis finds a valence-like component of the strange-quark PDF, giving rise to a nontrivial s- ¯ s asymmetry at moderate x values. We also review recent analyses of charm in the nucleon, which have found conflicting indications of the size of the nonperturbative charm component.

  20. Nucleon measurements at the precision frontier

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Carl E. [Physics Department, College of William and Mary, Williamsburg, VA 23187 (United States)

    2013-11-07

    We comment on nucleon measurements at the precision frontier. As examples of what can be learned, we concentrate on three topics, which are parity violating scattering experiments, the proton radius puzzle, and the symbiosis between nuclear and atomic physics.

  1. Cosmic Ray Helium Isotopes From 0.2 to 3.6 GeV/nucleon

    DEFF Research Database (Denmark)

    Reimer, O.; Hof, M.; Menn, W.

    1996-01-01

    mass by means of the velocity vs. magnetic rigidity technique. A model of the instrument response was developed in order to unfold the species and rigidity-dependent effects. Measurements and astrophysical interpretation of the ^3He/^4He isotope ratio from 0.2 to 3.6 GeV/nucleon will be presented...

  2. Magnetically assisted matrix solid phase dispersion for extraction of parabens from breast milks.

    Science.gov (United States)

    Fotouhi, Mina; Seidi, Shahram; Shanehsaz, Maryam; Naseri, Mohammad Taghi

    2017-06-30

    In the present work, magnetically assisted matrix solid phase dispersion (MA-MSPD) was used as an efficient solid phase extraction method. MA-MSPD followed by a dispersive liquid-liquid microextraction (DLLME) was applied for determination of parabens in breast milks. The analysis were performed using LC-UV and LC-MS/MS. Poly(indole-thiophene) coated magnetic graphene oxide (MGO@PIT) was synthesized, characterized and used as the sorbent. Na2SO4 was used as the drying salt as well as matrix dispersing agent. Exact amounts of MGO@PIT and Na2SO4 were added into 200μL volume of the milk and the mixture was gently blended to obtain a dry powder. The blend was dispersed into ultrapure water and stirred. Because of dissolving of the matrix dispersant in water, only the magnetic sorbent is remained into water which can be easily separated by a magnet. Next, the sorbent was eluted with a suitable solvent to desorb the analyte and the eluent was used as the disperser solvent for the subsequent DLLME. In this approach, the target analytes were directly adsorbed on the surface of the magnetic sorbent without any sample pretreatment. Compared with conventional MSPD, MA-MSPD increases the simplicity of the extraction procedure, decreases the extraction time and eliminates the column packing as well as its related drawbacks. The optimum extraction parameters were obtained as 50mg of MGO@PIT, 550mg of Na2SO4 in 200μL of the milk sample, 1.0mL of methanol as the eluent solvent under fierce vortex for 2.0min and 100μL of 1-octanol as the extraction solvent. Under the optimal conditions, the extraction recoveries greater than 83% were obtained, and LOD and LOQ values were found 25ngmL-1 (about 0.5ngmL-1 by LC-MS/MS) and 50ngmL-1 using LC-UV, respectively. The calibration curves were in the range of 50-4000ngmL-1 with the determination coefficients (R2) higher than 0.998. Relative standard deviations (RSD%) for intra- and inter-day precisions were less than 7.5% and 11

  3. Nucleon distribution amplitudes from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Goeckeler, M. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics; Kaltenbrunner, T. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (DE). John von Neumann-Inst. fuer Computing NIC] (and others)

    2008-04-15

    We calculate low moments of the leading-twist and next-to-leading twist nucleon distribution amplitudes on the lattice using two flavors of clover fermions. The results are presented in the MS scheme at a scale of 2 GeV and can be immediately applied in phenomenological studies. We find that the deviation of the leading-twist nucleon distribution amplitude from its asymptotic form is less pronounced than sometimes claimed in the literature. (orig.)

  4. A Novel Eddy Current Septum Magnet for SPS Extraction towards LHC and CNGS

    CERN Document Server

    Schröder, G H; Carlier, E; Dieperink, J H; Ducimetière, L; Goddard, B; Lázár, C; Mayer, M; Vossenberg, Eugène B; Weterings, W

    2000-01-01

    A new East Fast-Extraction System is under construction in the SPS, to supply particles with a maximum batch length of 7.8 us and 10.5 us to the LHC and to CNGS (CERN Neutrino to Gran Sasso), respectively. The extraction septum magnets actually used at the SPS have been designed for slow extraction over several seconds, have large cooling and electrical power demands and need frequently maintenance in a high radiation environment. A fast system of only 250 us pulse duration has therefore been developed, using a half-sine excitation pulse with a superimposed third harmonic. The short pulse duration requires very thin magnetic yoke laminations, which can not easily be stamped and stacked. Profiting from a development for the LHC beam dump kicker magnets, the yoke is therefore built-up from tape-wound cylindrical cores, employing 50 um thick Si-steel tape. Thirty two cores are stacked longitudinally to produce a yoke of 3.2 meter length. The aperture is cut radial into each cylinder. The cores are radial compres...

  5. A review of the nucleon-nucleon Paris potential

    Energy Technology Data Exchange (ETDEWEB)

    Loiseau, B. [Universite Pierre et Marie Curie, 75 - Paris (France). Inst. de Physique Nucleaire. Div. de Physiqe Theorique

    1997-12-31

    In this talk, after an introduction pointing out recent activity to explain the NN interaction in a more fundamental manner from the chiral symmetry of QCD, we present a preview of the NN Paris potential. We demonstrate the evidence for the one-pion exchange (OPE) in NN by analyzing neutron-proton (np) charge exchange differential cross section. This allows to determine the charged {pi} NN coupling constant. We recall how the next longest range force after that of OPE, i.e. that of the 2{pi} exchange, is calculated. Analiticity and unitarity allow to use dispersion relations. They express the NN amplitudes in terms of {pi}N and {pi}{pi} amplitudes. We then define the 2{pi}-exchange potential to be used in the Schroedinger equation. The unknown short range part where heavier meson exchanges and/or quark degree of freedom becomes important is parametrized and fitted to the data. In few body reactions one often needs initial or final state NN interactions. Those can be described in terms of scattering wave functions. A parametrization of the np scattering wave functions is given. We show how dispersion relations can be used to calculate NN peripheral inelasticities from {pi}N scattering amplitudes up to kinetic energies of 2.5 GeV. The quark degree of freedom is considered. We first test a short range quark cluster model supplemented by the long range Paris potential. We then describe a model for np scattering when we consider pion exchanges between the quarks constituents of the nucleon. Some recent nuclear calculations with the Paris potential are reviewed. In the conclusion we remark that dispersion relations constitute a constraint for any theory, in particular for recent chiral approaches, the long range of which should be compared to that of the Paris potential. An up to date Paris potential with chiral constraints from QCD will be welcome. (author) 70 refs., 6 figs., 2 tabs.

  6. Extraction and derivatization of chemical weapons convention relevant aminoalcohols on magnetic cation-exchange resins.

    Science.gov (United States)

    Singh, Varoon; Garg, Prabhat; Chinthakindi, Sridhar; Tak, Vijay; Dubey, Devendra Kumar

    2014-02-14

    Analysis and identification of nitrogen containing aminoalcohols is an integral part of the verification analysis of chemical weapons convention (CWC). This study was aimed to develop extraction and derivatization of aminoalcohols of CWC relevance by using magnetic dispersive solid-phase extraction (MDSPE) in combination with on-resin derivatization (ORD). For this purpose, sulfonated magnetic cation-exchange resins (SMRs) were prepared using magnetite nanoparticles as core, styrene and divinylbenzene as polymer coat and sulfonic acid as acidic cation exchanger. SMRs were successfully employed as extractant for targeted basic analytes. Adsorbed analytes were derivatized with hexamethyldisilazane (HMDS) on the surface of extractant. Derivatized (silylated) compounds were analyzed by GC-MS in SIM and full scan mode. The linearity of the method ranged from 5 to 200ngmL(-1). The LOD and LOQ ranged from 2 to 6ngmL(-1) and 5 to 19ngmL(-1) respectively. The relative standard deviation for intra-day repeatability and inter-day intermediate precision ranged from 5.1% to 6.6% and 0.2% to 7.6% respectively. Recoveries of analytes from spiked water samples from different sources varied from 28.4% to 89.3%. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Dispersive liquid-liquid microextraction coupled with magnetic nanoparticles for extraction of zearalenone in wheat samples

    Directory of Open Access Journals (Sweden)

    Mitra Amoli-Diva

    2017-01-01

    Full Text Available A new, sensitive and fast dispersive liquid-liquid microextraction (DLLME coupled with micro-solid phase extraction (μ-SPE was developed for determination of zearalenone (ZEN in wheat samples. The DLLME was performed using acetonitrile/water (80:20 v/v as the disperser solvent and 1-octanol as the extracting solvent.  The acetonitrile/water (80:20 v/v solvent was also used to extract ZEN from solid wheat matrix, and was directly applied as the disperser solvent for DLLME process. Additionally, hydrophobic oleic-acid-modified magnetic nanoparticles were used in μ-SPE approach to retrieve the analyte from the DLLME step. So, the method uses high surface area and strong magnetism properties of these nanoparticles to avoid time-consuming column-passing processes in traditional SPE. Main parameters affecting the extraction efficiency and signal enhancement were investigated and optimized. Under the optimum conditions, the calibration curve showed a good linearity in the range of 0.1-500 μg kg−1 (R2=0.9996 with low detection limit of 83 ng g−1. The intra-day and inter-day precisions (as RSD % in the range of 2.6-4.3 % and high recoveries ranging from 91.6 to 99.1 % were obtained. The pre-concentration factor was 3. The method is simple, inexpensive, accurate and remarkably free from interference effects.

  8. Nucleon structure from Lattice QCD using a nearly physical pion mass

    Energy Technology Data Exchange (ETDEWEB)

    Green, J.R. [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz (Germany); Engelhardt, M. [Department of Physics, New Mexico State University, Las Cruces, NM 88003 (United States); Krieg, S. [Bergische Universität Wuppertal, D-42119 Wuppertal (Germany); IAS, Jülich Supercomputing Centre, Forschungszentrum Jülich, D-52425 Jülich (Germany); Negele, J.W.; Pochinsky, A.V. [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Syritsyn, S.N., E-mail: ssyritsyn@quark.phy.bnl.gov [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); RIKEN/BNL Research Center, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2014-06-27

    We report the first Lattice QCD calculation using the almost physical pion mass m{sub π}=149 MeV that agrees with experiment for four fundamental isovector observables characterizing the gross structure of the nucleon: the Dirac and Pauli radii, the magnetic moment, and the quark momentum fraction. The key to this success is the combination of using a nearly physical pion mass and excluding the contributions of excited states. An analogous calculation of the nucleon axial charge governing beta decay has inconsistencies indicating a source of bias at low pion masses not present for the other observables and yields a result that disagrees with experiment.

  9. Lattice QCD Calculation of Nucleon Structure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Keh-Fei [University of Kentucky, Lexington, KY (United States). Dept. of Physics and Astronomy; Draper, Terrence [University of Kentucky, Lexington, KY (United States). Dept. of Physics and Astronomy

    2016-08-30

    It is emphasized in the 2015 NSAC Long Range Plan that "understanding the structure of hadrons in terms of QCD's quarks and gluons is one of the central goals of modern nuclear physics." Over the last three decades, lattice QCD has developed into a powerful tool for ab initio calculations of strong-interaction physics. Up until now, it is the only theoretical approach to solving QCD with controlled statistical and systematic errors. Since 1985, we have proposed and carried out first-principles calculations of nucleon structure and hadron spectroscopy using lattice QCD which entails both algorithmic development and large-scale computer simulation. We started out by calculating the nucleon form factors -- electromagnetic, axial-vector, πNN, and scalar form factors, the quark spin contribution to the proton spin, the strangeness magnetic moment, the quark orbital angular momentum, the quark momentum fraction, and the quark and glue decomposition of the proton momentum and angular momentum. The first round of calculations were done with Wilson fermions in the `quenched' approximation where the dynamical effects of the quarks in the sea are not taken into account in the Monte Carlo simulation to generate the background gauge configurations. Beginning in 2000, we have started implementing the overlap fermion formulation into the spectroscopy and structure calculations. This is mainly because the overlap fermion honors chiral symmetry as in the continuum. It is going to be more and more important to take the symmetry into account as the simulations move closer to the physical point where the u and d quark masses are as light as a few MeV only. We began with lattices which have quark masses in the sea corresponding to a pion mass at ~ 300 MeV and obtained the strange form factors, charm and strange quark masses, the charmonium spectrum and the Ds meson decay constant fDs, the strangeness and charmness, the meson mass

  10. Signatures of three-nucleon interactions in few-nucleon systems

    NARCIS (Netherlands)

    Kalantar-Nayestanaki, N.; Epelbaum, E.; Messchendorp, J. G.; Nogga, A.

    Recent experimental results in three-body systems have unambiguously shown that calculations based only on nucleon-nucleon forces fail to accurately describe many experimental observables and one needs to include effects which are beyond the realm of the two-body potentials. This conclusion owes its

  11. Low-energy theorems for virtual nucleon-nucleon bremsstrahlung; Formalism and results

    NARCIS (Netherlands)

    Korchin, AY; Scholten, O; VanNeck, D

    1996-01-01

    We present results for cross sections and response functions in virtual bremsstrahlung induced by nucleon-nucleon collisions NN --> NN + e(+)e(-), based on two different low-energy theorems, The first low-energy theorem is a generalization of Low's theorem for real-photon bremsstrahlung. The second

  12. Extraction of triazole fungicides in environmental waters utilizing poly (ionic liquid)-functionalized magnetic adsorbent.

    Science.gov (United States)

    Liu, Cheng; Liao, Yingmin; Huang, Xiaojia

    2017-11-17

    This work prepared a new poly (ionic liquid)-functionalized magnetic adsorbent (PFMA) for the extraction of triazole fungicides (TFs) in environmental waters prior to determination by high performance liquid chromatography/diode array detection (HPLC-DAD). A polymerizable ionic liquid, 1-methyl-3-allylimidazolium bis(trifluoromethylsulfonyl)imide was employed to copolymerize with divinylbenzene on the surface of modified magnetite to fabricate the PFMA. The morphology, spectroscopic and magnetic properties of the new adsorbent were investigated by different techniques. A series of key parameters that influence the extraction performance including the amount of PFMA, desorption solvent, adsorption and desorption time, sample pH value and ionic strength were optimized in detail. Under the optimum conditions, the prepared PFMA could extract targeted TFs effectively and quickly under the format of magnetic solid-phase extraction (MSPE). Satisfactory linearities were achieved in the range of 0.1-200.0μg/L for triadimenol and 0.05-200.0μg/L for other TFs with good coefficients of determination above 0.99 for all analytes. The limits of detection (S/N=3) and limits of quantification (S/N=10) for TFs were in the range of 0.0050-0.0078μg/L and 0.017-0.026μg/L, respectively. Environmental waters including lake, river and well waters were used to demonstrate the applicability of developed MSPE-HPLC-DAD method, and satisfactory recoveries and repeatability were obtained. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Highly efficient extraction of phenolic compounds by use of magnetic room temperature ionic liquids for environmental remediation

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Ning [School of Chemical Engineering, Hefei University of Technology, Hefei, Anhui Province 230009 (China); Li, Min; Zhao, Lijie; Lu, Chengfei; Rooy, Sergio L. de [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Warner, Isiah M., E-mail: iwarner@lsu.edu [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States)

    2011-09-15

    Highlights: {yields} Novel separation technique based on the use of magnetic extraction. {yields} Using a magnetic room temperature ionic liquid for removal of hazardous phenols from contaminated soil samples. {yields} Inherently safer and cleaner technique demonstrated highest extraction capacity as compared with previous regular non-magnetic RTILs. {yields} Successfully remove highly hazardous pentachlorophenol from superfund site contaminated soil samples with extremely high extraction capacity. {yields} Contributions of our work focus primarily on remediation of contaminated soil and groundwater. - Abstract: A hydrophobic magnetic room temperature ionic liquid (MRTIL), trihexyltetradecylphosphonium tetrachloroferrate(III) ([3C{sub 6}PC{sub 14}][FeCl{sub 4}]), was synthesized from trihexyltetradecylphosphonium chloride and FeCl{sub 3}.6H{sub 2}O. This MRTIL was investigated as a possible separation agent for solvent extraction of phenolic compounds from aqueous solution. Due to its strong paramagnetism, [3C{sub 6}PC{sub 14}][FeCl{sub 4}] responds to an external neodymium magnet, which was employed in the design of a novel magnetic extraction technique. The conditions for extraction, including extraction time, volume ratio between MRTIL and aqueous phase, pH of aqueous solution, and structures of phenolic compounds were investigated and optimized. The magnetic extraction of phenols achieved equilibrium in 20 min and the phenolic compounds were found to have higher distribution ratios under acidic conditions. In addition, it was observed that phenols containing a greater number of chlorine or nitro substituents exhibited higher distribution ratios. For example, the distribution ratio of phenol (D{sub Ph}) was 107. In contrast, 3,5-dichlorophenol distribution ratio (D{sub 3,5-DCP}) had a much higher value of 6372 under identical extraction conditions. When compared with four selected traditional non-magnetic room temperature ionic liquids, our [3C{sub 6}PC{sub 14

  14. Isospin mixing in the nucleon and He-4 and the nucleon strange electric form-factor

    Energy Technology Data Exchange (ETDEWEB)

    M. Viviani; R. Schiavilla; B. Kubis; R. Lewis; L. Girlanda; A. Kievsky; L.E. Marcucci; S. Rosati

    2007-09-01

    In order to isolate the contribution of the nucleon strange electric form factor to the parity-violating asymmetry measured in 4He(\\vec e,e')4He experiments, it is crucial to have a reliable estimate of the magnitude of isospin-symmetry-breaking (ISB) corrections in both the nucleon and 4He. We examine this issue in the present letter. Isospin admixtures in the nucleon are determined in chiral perturbation theory, while those in 4He are derived from nuclear interactions, including explicit ISB terms. A careful analysis of the model dependence in the resulting predictions for the nucleon and nuclear ISB contributions to the asymmetry is carried out. We conclude that, at the low momentum transfers of interest in recent measurements reported by the HAPPEX collaboration at Jefferson Lab, these contributions are of comparable magnitude to those associated with strangeness components in the nucleon electric form factor.

  15. Magnetic ionic liquids as extraction solvents in vacuum headspace single-drop microextraction.

    Science.gov (United States)

    Trujillo-Rodríguez, María J; Pino, Verónica; Anderson, Jared L

    2017-09-01

    A vacuum headspace single-drop microextraction method based on the use of magnetic ionic liquids (vacuum MIL-HS-SDME) for the determination of short chain free fatty acids is described for the first time. The basis of the method involves the use of a rod magnet to aid in maintaining a small microdroplet of magnetic ionic liquid (MIL) during headspace single-drop microextraction (HS-SDME). The application favors reduced pressure conditions inside the sampling vial while maintaining the MIL droplet in the headspace. After extraction, the MIL microdroplet containing extracted FFAs is transferred to a headspace vial where static headspace desorption is performed, followed by gas chromatographic-mass spectrometry (GC-MS) analysis. A number of MILs were studied and the trihexyl(tetradecyl)phosphonium tris(hexafluoroacetylaceto)manganate(II) MIL was found to be the most suitable for the proposed method. A comparison with atmospheric pressure MIL-HS-SDME revealed that analytes reached equilibrium faster when reduced pressure conditions were applied and that an enhancement in the extraction efficiency of analytes under these vacuum conditions was observed at any extraction time. Under optimum conditions, the method requires only 20µL of MIL placed at the end of a rod magnet and the evacuation of air using a modified extraction vial and a vacuum pump. Afterwards, 10mL of sample containing 30% (w/v) of NaCl is injected in the vial and the vacuum MIL-HS-SDME is performed at 45°C and 600rpm for 60min. The MIL microdroplet can easily be transferred to a 4.2mL modified headspace vial for the headspace desorption and GC-MS analysis. The entire method is characterized by wide linearity ranges, low limits of detection for analytes (down to 14.5µgL-1), good reproducibility (with relative standard deviation lower than 13%), and relative recoveries ranging from 79.5% to 111%. The proposed vacuum MIL-HS-SDME was applied towards the analysis of two different milk samples with the

  16. Unusual seeding mechanism for enhanced performance in solid-phase magnetic extraction of Rare Earth Elements.

    Science.gov (United States)

    Polido Legaria, Elizabeth; Rocha, Joao; Tai, Cheuk-Wai; Kessler, Vadim G; Seisenbaeva, Gulaim A

    2017-03-07

    Due to the increasing demand of Rare Earth Elements (REE or RE), new and more efficient techniques for their extraction are necessary, suitable for both mining and recycling processes. Current techniques such as solvent extraction or solid adsorbents entail drawbacks such as using big volumes of harmful solvents or limited capacity. Hybrid nanoadsorbents based on SiO 2 and highly stable γ-Fe 2 O 3 -SiO 2 nanoparticles, proved recently to be very attractive for adsorption of REE, yet not being the absolute key to solve the problem. In the present work, we introduce a highly appealing new approach in which the nanoparticles, rather than behaving as adsorbent materials, perform as inducers of crystallization for the REE in the form of hydroxides, allowing their facile and practically total removal from solution. This induced crystallization is achieved by tuning the pH, offering an uptake efficiency more than 20 times higher than previously reported (up to 900 mg RE 3+ /g vs. 40 mg RE 3+ /g). The obtained phases were characterized by SEM-EDS, TEM, STEM and EFTEM and 13 C and 29 Si solid state NMR. Magnetic studies showed that the materials possessed enough magnetic properties to be easily removed by a magnet, opening ways for an efficient and industrially applicable separation technique.

  17. Quark sea structure functions of the nucleon in a statistical model

    Science.gov (United States)

    Trevisan, L. A.; Mirez, C.; Frederico, T.; Tomio, L.

    2008-07-01

    Within a statistical model of linear confined quarks we obtain the flavor asymmetry and corresponding structure function of the nucleon. The model parameters are fixed by the experimental available data. The temperature parameter is adjusted by the Gottfried sum rule violation and the chemical potentials by the corresponding up (u) and down (d) quark normalizations in the nucleon. The light antiquark and quark distributions in the proton, given by d¯/ū, d/u and d¯-ū, as well as the neutron to proton ratio of the structure functions, extracted from the experimental data, are well fitted by the model. As the quark-confining strengths should be flavor dependent, a mechanism is introduced in the model to adjust the corresponding distribution, in order to improve the comparison obtained for the sea-quark asymmetries in the nucleon with the available experimental analysis.

  18. Nucleon Structure and Hyperon Form Factors from Lattice QCD.

    Energy Technology Data Exchange (ETDEWEB)

    Lin,H.W.

    2007-06-11

    In this work, I report the latest lattice QCD calculations of nucleon and hyperon structure from chiral fermions in 2+1-flavor dynamical simulations. All calculations are done with a chirally symmetric fermion action, domain-wall fermions, for valence quarks. I begin with the latest lattice results on the nucleon structure, focusing on results from RBC/UKQCD using 2+1-flavor chiral fermion actions. We find the chiral-extrapolated axial coupling constant at physical pion mass point. to be 1.23(5), consistent with experimental value. The renormalization constants for the structure functions are obtained from RI/MOM-scheme non-perturbative renormalization. We find first moments of the polarized and unpolarized nucleon structure functions at zero transfer momentum to be 0.133(13) and 0.203(23) respectively, using continuum chiral extrapolation. These are consistent with the experimental values, unlike previous calculations which have been 50% larger. We also have a prediction for the transversity, which we find to be 0.56(4). The twist-3 matrix element is consistent with zero which agrees with the prediction of the Wandzura-Wilczek relation. In the second half of this work, I report an indirect dynamical estimation of the strangeness proton magnetic moments using mixed actions. With the analysis of hyperon form factors and using charge symmetry, the strangeness of proton is found to be -0.066(2G), consistent with the Adelaide-JLab Collaboration's result. The hyperon {Sigma} and {Xi} axial coupling constants are also performed for the first time in a lattice calculation, g{sub {Sigma}{Sigma}} = 0.441(14) and g{sub {Xi}{Xi}} = -0.277(11).

  19. Nucleon Structure and hyperon form factors from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Huey-Wen

    2007-06-11

    In this work, I report the latest lattice QCD calculations of nucleon and hyperon structure from chiral fermions in 2+1-flavor dynamical simulations. All calculations are done with a chirally symmetric fermion action, domain-wall fermions, for valence quarks. I begin with the latest lattice results on the nucleon structure, focusing on results from RBC/UKQCD using 2+1-flavor chiral fermion actions. We find the chiral-extrapolated axial coupling constant at physical pion mass point to be 1.23(5), consistant with experimental value. The renormalization constants for the structure functions are obtained from RI/MOM-scheme non-perturbative renormalization. We find first moments of the polarized and unpolarized nucleon structure functions at zero transfer momentum to be 0.133(13) and 0.203(23) respectively, using continuum chiral extrapolation. These are consistent with the experimental values, unlike previous calculations which have been 50% larger. We also have a prediction for the transversity, which we find to be 0.56(4). The twist-3 matrix element is consistent with zero which agrees with the prediction of the Wandzura-Wilczek relation. In the second half of this work, I report an indirect dynamical estimation of the strangeness proton magnetic moments using mixed actions. With the analysis of hyperon form factors and using charge symmetry, the strangeness of proton is found to be -0.066(26), consistent with the Adelaide-JLab Collaboration's result. The hyperon Sigma and Xi axial coupling constants are also performed for the first time in a lattice calculation, g_SigmaSigma = 0.441(14) and g_XiXi = -0.277(11).

  20. Magnetic Solid-Phase Extraction Based on β-Cyclodextrins/Acrylic Acid Modified Magnetic Gelatin for Determination of Moxidectin in Milk Samples

    Directory of Open Access Journals (Sweden)

    Yinzhu Shang

    2016-01-01

    Full Text Available β-Cyclodextrins/acrylic acid modified magnetic gelatin was prepared and then employed as the magnetic solid-phase extraction (MSPE sorbent for extraction of moxidectin in milk samples. Due to the rigidity of hydrophobic cavity of β-cyclodextrins and carboxyl groups of acrylic acid, magnetic composites are prepared to form a complex with target molecules through various kinds of chemical reactions and then showed excellent extraction performance. This method exhibits the advantages of simplicity of implementation, short extraction time (5 min, low solvent consumption, and high extraction efficiency. A rapid, simple, and effective method for the analysis of moxidectin in milk samples was established by MSPE coupled with liquid chromatography-fluorescence detection. The limit of detection was 0.1 ng·mL−1 and the recoveries from milk samples were in the range of 93.8%–112.5%. The relative standard deviation was not higher than 6.4%. In conclusion, magnetic solid-phase extraction is a simple and robust preconcentration technique that can be coupled to other analytical methods for the quantitative determination of target molecules in complex samples.

  1. The strange spin of the nucleon

    CERN Document Server

    Ellis, John R.; Ellis, John; Karliner, Marek

    1997-01-01

    The recent series of experiments on polarized lepton-nucleon scattering have provided a strange new twist in the story of the nucleon, some of whose aspects are reviewed in these lectures. In the first lecture, we review some issues arising in the analysis of the data on polarized structure functions, focusing in particular on the importance and treatment of high-order QCD perturbation theory. In the second lecture some possible interpretations of the ``EMC spin effect" are reviewed, principally in the chiral soliton (Skyrmion) approach, but also interpretations related to the axial U(1) anomaly. This lecture also discusses other indications from recent LEAR data for an \\bar{s} s component in the nucleon wave function, and discusses test of a model for this component. Finally, the third lecture reviews the implications of polarized structure functions measurements for experiments to search for cold dark matter particles, such as the lightest supersymmetric particle and the axion, after reviewing briefly the a...

  2. Nucleon-nucleon correlations, short-lived excitations, and the quarks within

    Science.gov (United States)

    Hen, Or; Miller, Gerald A.; Piasetzky, Eli; Weinstein, Lawrence B.

    2017-10-01

    This article reviews our current understanding of how the internal quark structure of a nucleon bound in nuclei differs from that of a free nucleon. The interpretation of measurements of the European Muon Collaboration (EMC) effect for valence quarks, a reduction in the deep inelastic scattering cross-section ratios for nuclei relative to deuterium, and its possible connection to nucleon-nucleon short-range correlations (SRCs) in nuclei are focused on. This review and new analysis (involving the amplitudes of non-nucleonic configurations in the nucleus) of the available experimental and theoretical evidence shows that there is a phenomenological relation between the EMC effect and the effects of SRCs that is not an accident. The influence of strongly correlated neutron-proton pairs involving highly virtual nucleons is responsible for both effects. These correlated pairs are temporary high-density fluctuations in the nucleus in which the internal structure of the nucleons is briefly modified. This conclusion needs to be solidified by the future experiments and improved theoretical analyses that are discussed herein.

  3. Three-nucleon reactions with chiral dynamics*

    Directory of Open Access Journals (Sweden)

    Witała H.

    2014-03-01

    Full Text Available Faddeev calculations using the chiral three-nucleon force at next-to-next-to-next-to-leading-order show that this force is not able to provide an explanation for the low-energy Ay puzzle. Also the large discrepancies between data and theory for the symmetric-space-star and for the neutron-neutron quasi-free-scattering cross sections in low energy neutron-deuteron breakup cannot be explained by that three-nucleon force. The discrepancy for the neutron-neutron quasi-free-scattering cross section seems to require a modification of the 1S0 neutron-neutron force.

  4. Synthesis of a novel polymeric magnetic solid phase extraction adsorbent for selective extraction of amphetamine from urine samples coupled with high performance liquid chromatography.

    Science.gov (United States)

    Taghvimi, Arezou; Ghorbani, Marjan; Hamishehkar, Hamed

    2017-11-18

    A novel pH-responsive block copolymer (Poly ethylene glycol-b-poly (N,N-dimethylaminoethylmethacrylate-co-maleic acid) was designed for the decoration and stabilization of magnetic nanoparticles (MNPs) as an efficient magnetic nano adsorbent for extraction of amphetamine (AM) from biological urine samples to be determined by high performance liquid chromatography-ultra violet detector (HPLC-UV). Full characterization of the synthesized polymeric magnetic nanoparticles (PMNPs) were followed by various techniques like Fourier transform infrared (FT-IR) spectroscopy, powder x-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). Important extraction parameters including pH, amount of sample volume, amount of adsorbent, type and amount of extraction organic solvent, time of extraction and desorption, agitation rate (rpm), and ionic strength of the extraction medium were studied and optimized. Under optimized extraction conditions, good linearity was observed in the concentration range of 30-2000 ng/mL for AM. The amount of the qe was calculated as 0.18 (mg/g). The method was applied in determination of AM from positive urine samples with the recovery of 99.84%. Results indicated that the proposed method could be applied in clinical and forensic laboratories for simple, selective, and fast determination of AM from urine samples. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Preparation of magnetic graphene @polydopamine @Zr-MOF material for the extraction and analysis of bisphenols in water samples.

    Science.gov (United States)

    Wang, Xianying; Deng, Chunhui

    2015-11-01

    In this work, a simple method for the extraction and analysis of bisphenols in environmental samples was presented. And the prepared zirconium-based magnetic MOFs (magG@PDA@Zr-MOF) were used as the sorbents for the magnetic solid-phase extraction. With the simple solvothermal reaction and sol-gel method, the prepared material showed great characteristics of large surface area, homogeneous pore size, good magnetic responsivity and super-hydrophilicity. The large surface area provided abundant sites to extract target compounds; the magnetic property could simplify the whole extraction procedure; and the hydrophilicity improved the dispersibility of the material in matrix. Here, various extraction parameters were optimized, including amounts of sorbents, adsorption time, species of elution solvents and desorption time. The whole extraction procedure could be accomplished in 30 min. And under the optimized conditions, method validations were also studied, such as linearity, the limit of detection and recovery. Finally, the prepared material was used in real water samples. The results showed this material had good potential as the sorbent for the extraction of targets in environmental water samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Magnetic/non-magnetic argan press cake nanocellulose for the selective extraction of sudan dyes in food samples prior to the determination by capillary liquid chromatograpy.

    Science.gov (United States)

    Benmassaoud, Yassine; Villaseñor, María J; Salghi, Rachid; Jodeh, Shehdeh; Algarra, Manuel; Zougagh, Mohammed; Ríos, Ángel

    2017-05-01

    Two methods for the determination of Sudan dyes (Sudan I, Sudan II, Sudan III and Sudan IV) in food samples, by solid phase extraction - capillary liquid chromatography, are proposed. Both methods use nanocellulose (NC) extracted from bleached argan press cake (APC), as a nano-adsorbent recycled from an agricultural waste material. One of the methods involves the dispersion of NC in food sample extracts, along with the waste and eluents being separated by centrifugation. In the other method, NC was modified by magnetic iron nanoparticles before using it in the extraction of Sudan dyes. The use of a magnetic component in the extraction process allows magnetic separation to replace the centrifugation step in a convenient and economical way. The two proposed methods allows the determination of Sudan dye amounts at the 0.25-2.00µgL(-1) concentration range. The limit of detections, limit of quantifications and standard deviations achieved were lower than 0.1µgL(-1), 0.20µgL(-1) and 3.46% respectively, when using NC as a nano-adsorbent, and lower than 0.07µgL(-1), 0.23µgL(-1) and 2.62%, respectively, with the magnetic nanocellulose (MNC) was used. Both methods were applied to the determination of Sudan dyes in barbeque and ketchup sauce samples, obtaining recoveries between 93.4% and 109.6%. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Auto-context Convolutional Neural Network (Auto-Net) for Brain Extraction in Magnetic Resonance Imaging.

    Science.gov (United States)

    Salehi, Seyed Sadegh Mohseni; Erdogmus, Deniz; Gholipour, Ali

    2017-06-28

    Brain extraction or whole brain segmentation is an important first step in many of the neuroimage analysis pipelines. The accuracy and robustness of brain extraction, therefore, is crucial for the accuracy of the entire brain analysis process. State-of-the-art brain extraction techniques rely heavily on the accuracy of alignment or registration between brain atlases and query brain anatomy, and/or make assumptions about the image geometry; therefore have limited success when these assumptions do not hold or image registration fails. With the aim of designing an accurate, learning-based, geometry-independent and registration-free brain extraction tool in this study, we present a technique based on an auto-context convolutional neural network (CNN), in which intrinsic local and global image features are learned through 2D patches of different window sizes. We consider two different architectures: 1) a voxelwise approach based on three parallel 2D convolutional pathways for three different directions (axial, coronal, and sagittal) that implicitly learn 3D image information without the need for computationally expensive 3D convolutions, and 2) a fully convolutional network based on the U-net architecture. Posterior probability maps generated by the networks are used iteratively as context information along with the original image patches to learn the local shape and connectedness of the brain to extract it from non-brain tissue. The brain extraction results we have obtained from our CNNs are superior to the recently reported results in the literature on two publicly available benchmark datasets, namely LPBA40 and OASIS, in which we obtained Dice overlap coefficients of 97.73% and 97.62%, respectively. Significant improvement was achieved via our auto-context algorithm. Furthermore, we evaluated the performance of our algorithm in the challenging problem of extracting arbitrarily-oriented fetal brains in reconstructed fetal brain magnetic resonance imaging (MRI

  8. Three-nucleon scattering by using chiral perturbation theory potential

    Energy Technology Data Exchange (ETDEWEB)

    Kamata, Hiroyuki [Kyushu Inst. of Technology, Faculty of Engineering, Kita-kyushu, Fukuoka (Japan)

    2003-01-01

    Three-nucleon scattering problems are studied by using two-nucleon and three-nucleon potentials derived from chiral perturbation theory. The three-nucleon term is shown to appear in the effective potential of the rank of next-to-next-to-leading order (NNLO). New three-nucleon forces are taken into consideration in addition to the conventional Fujita-Miyazawa (FM) type three-nucleon potential. Two-nucleon potential of the chiral perturbation theory is as precise as the conventional ones in low energy region. The FM type three-nucleon force which explains Sagara discrepancy in high energy region is introduced automatically. Concerning the Ay puzzle, the results seems to behave as if the puzzle has been solved at the level of NLO, but at the NNLO (without three-nucleon force) level the result is similar to the cases of conventional potential indicating the need of three-nucleon force. In contrast to the FM type three-nucleon force, five free parameters exist in the new D and E type three-nucleon forces introduced by the NNLO, but they are reduced to two independent parameters by antisymmetrization, which are found to be sensitive to the coupling energy of tritons and to the nd scattering length (spin doublet state). Parameters determined from them cannot give satisfactory answer to the A{sub y} puzzle. It seems, however, too hasty to conclude that A{sub y} puzzle cannot be solved by the chiral perturbation theory. (S. Funahashi)

  9. Extraction of melamine from milk using a magnetic molecularly imprinted polymer.

    Science.gov (United States)

    Anirudhan, T S; Christa, J; Deepa, J R

    2017-07-15

    A novel magnetic molecularly imprinted polymer (MMIP) for the preconcentration of melamine, a non-protein nitrogen food additive from complex matrices was synthesized and characterized using FT-IR, XRD, SEM and VSM techniques. Surface imprinting was done on vinyltrimethoxysilane coated Fe3O4 (Fe3O4-VTMS) using 2-acrylamido-2-methylpropane sulfonic acid (AMPS), N,N'-methylenebisacrylamide (MBA) and potassium persulfate (KPS) as functional monomer, crosslinker and initiator respectively. Saturation magnetization value obtained for MMIP was 1.72emug-1. Binding studies showed that MMIP exhibits good recognition to melamine compared to magnetic non imprinted polymer (MNIP). The optimum pH for the binding of melamine was found to be 4.5. Binding process was very fast and pseudo-second-order model fitted well with the kinetic data. Binding isotherm followed Langmuir isotherm model of monolayer adsorption with a maximum melamine binding efficiency of 62.25mgg-1. The HPLC-UV analysis results revealed the applicability of MMIP in solid phase extraction and determination of melamine from milk samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Studies in the Use of Magnetic Microspheres for Immunoaffinity Extraction of Paralytic Shellfish Poisoning Toxins from Shellfish

    Directory of Open Access Journals (Sweden)

    Christopher Elliott

    2011-01-01

    Full Text Available Paralytic shellfish poisoning (PSP is a potentially fatal human health condition caused by the consumption of shellfish containing high levels of PSP toxins. Toxin extraction from shellfish and from algal cultures for use as standards and analysis by alternative analytical monitoring methods to the mouse bioassay is extensive and laborious. This study investigated whether a selected MAb antibody could be coupled to a novel form of magnetic microsphere (hollow glass magnetic microspheres, brand name Ferrospheres-N and whether these coated microspheres could be utilized in the extraction of low concentrations of the PSP toxin, STX, from potential extraction buffers and spiked mussel extracts. The feasibility of utilizing a mass of 25 mg of Ferrospheres-N, as a simple extraction procedure for STX from spiked sodium acetate buffer, spiked PBS buffer and spiked mussel extracts was determined. The effects of a range of toxin concentrations (20–300 ng/mL, incubation times and temperature on the capability of the immuno-capture of the STX from the spiked mussel extracts were investigated. Finally, the coated microspheres were tested to determine their efficiency at extracting PSP toxins from naturally contaminated mussel samples. Toxin recovery after each experiment was determined by HPLC analysis. This study on using a highly novel immunoaffinity based extraction procedure, using STX as a model, has indicated that it could be a convenient alternative to conventional extraction procedures used in toxin purification prior to sample analysis.

  11. Polymeric ionic liquid based on magnetic materials fabricated through layer-by-layer assembly as adsorbents for extraction of pesticides.

    Science.gov (United States)

    He, Lijun; Cui, Wenhang; Wang, Yali; Zhao, Wenjie; Xiang, Guoqiang; Jiang, Xiuming; Mao, Pu; He, Juan; Zhang, Shusheng

    2017-11-03

    In this study, layer-by-layer assembly of polyelectrolyte multilayer films on magnetic silica provided a convenient and controllable way to prepare polymeric ionic liquid-based magnetic adsorbents. The resulting particles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and magnetic measurements. The data showed that the magnetic particles had more homogeneous spherical shapes with higher saturation magnetization when compared to those obtained by free radical polymerization method. This facilitated the convenient collection of magnetic particles, with higher extraction repeatability. The extraction performance of the multilayer polymeric ionic liquid-based adsorbents was evaluated by magnetic solid-phase extraction of four pesticides including quinalphos, fenthion, phoxim, and chlorpropham. The data suggested that the extraction efficiency depended on the number of layers in the film. The parameters affecting the extraction efficiency were optimized, and good linearity ranging from 2 to 250μgL-1 was obtained with correlation coefficients of 0.9994-0.9998. Moreover, the proposed method presented low limit of detection (0.5μgL-1, S/N=3) and limit of quantification (1.5μgL-1, S/N=10), and good repeatability expressed by the relative standard deviation (2.0%-4.6%, n=5). The extraction recoveries of four pesticides were found to range from 58.9% to 85.8%. The reliability of the proposed method was demonstrated by analyzing environmental water samples, and the results revealed satisfactory spiked recovery, relative standard deviation, and selectivity. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Three-nucleon forces and their importance in three-nucleon systems and heavier nuclei

    Directory of Open Access Journals (Sweden)

    Kalantar-Nayestanaki N.

    2014-03-01

    Full Text Available In the past two decades, several laboratories have produced a large amount of data for cross sections, analyzing powers, and other spin observables from various reactions in the three-nucleon system. The experimental results are moderately described by only using the two-nucleon potentials in Faddeev-type calculations. The remaining discrepancies should, in principle, and aside from Coulomb and relativistic effects, be removed once the effects of three-nucleon forces are implemented. High precision data on elastic and break-up reactions show, however, that even after the inclusion of these effects, the picture is not complete yet and some ingredients are still missing in the calculations. With the advent of new frameworks within which two and three-nucleon forces can be properly implemented in the calculation of observables in heavy nuclei, it is essential that these forces are better understood.

  13. Chiral perturbation theory and nucleon polarizabilities

    Energy Technology Data Exchange (ETDEWEB)

    Babusci, D.; Giordano, G.; Matone, G. [INFN, Laboratori Nazionali di Frascati, Rome (Italy)

    1996-10-01

    The available experimental data concerning the unpolarized cross section for the Compton scattering on the nucleon at low energy are compared with the predictions of the heavy baryon chiral perturbation theory (HBChPT) at the order q{sup 3}.

  14. Introduction to Nucleonics: A Laboratory Course.

    Science.gov (United States)

    Phelps, William; And Others

    This student text and laboratory manual is designed primarily for the non-college bound high school student. It can be adapted, however, to a wide range of abilities. It begins with an examination of the properties of nuclear radiation, develops an understanding of the fundamentals of nucleonics, and ends with an investigation of careers in areas…

  15. Extraction of ochratoxin A in red wine with dopamine-coated magnetic multi-walled carbon nanotubes.

    Science.gov (United States)

    Wan, Hong; Zhang, Bo; Bai, Xiao-Lin; Zhao, Yan; Xiao, Meng-Wei; Liao, Xun

    2017-10-01

    A new, rapid, green, and cost-effective magnetic solid-phase extraction of ochratoxin A from red wine samples was developed using polydopamine-coated magnetic multi-walled carbon nanotubes as the absorbent. The polydopamine-coated magnetic multi-walled carbon nanotubes were fabricated with magnetic multi-walled carbon nanotubes and dopamine by an in situ oxidative self-polymerization approach. Transmission electron microscopy, dynamic light scattering, X-ray photoelectron spectroscopy and vibrating sample magnetometry were used to characterize the absorbents. Ochratoxin A was quantified with high-performance liquid chromatography coupled with fluorescence detection, with excitation and emission wavelengths of 338 and 455 nm, respectively. The conditions affecting the magnetic solid-phase extraction procedure, such as pH, extraction solution, extraction time, absorbent amount, desorption solution and desorption time were investigated to obtain the optimal extraction conditions. Under the optimized conditions, the extraction recovery was 91.8-104.5% for ochratoxin A. A linear calibration curve was obtained in the range of 0.1-2.0 ng/mL. The limit of detection was 0.07 ng/mL, and the limit of quantitation was 0.21 ng/mL. The recoveries of ochratoxin A for spiked red wine sample ranged from 95.65 to 100.65% with relative standard deviation less than 8%. The polydopamine-coated magnetic multi-walled carbon nanotubes showed a high affinity toward ochratoxin A, allowing selective extraction and quantification of ochratoxin A from complex sample matrixes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Polarization phenomena in nucleon-nucleon scattering at intermediate and high energies including the present status of dibaryons

    Energy Technology Data Exchange (ETDEWEB)

    Yokosawa, A.

    1985-01-01

    We review experimental results concerning polarization phenomena in nucleon-nucleon scattering in which both the elastic scattering and hadron-production reaction are included. We also present summary of S = 0 dibaryon resonances and candidates by reviewing experimental data in the nucleon-nucleon system, ..gamma..d channel, ..pi..d elastic scattering, pp ..-->.. ..pi..d channel, deuteron break-up reactions, and narrow structures in missing-mass spectra. 93 refs., 26 figs.

  17. From nuclei to nucleons. [10 to 200 MeV/nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Scott, D.K.

    1978-03-01

    Some initial experiments in the intermediate energy region between 10 and 200 MeV/nucleon, which is largely unexplored and poorly understood is considered as regards some initial experiments in this energy region. Included are the emission of complex fragments, localization in heavy ion reactions, coincidence experiments between light and heavy fragments, and the emission of light particles in heavy ion collisions. Some initial results in the region between 20 and 100 MeV/nucleon are presented. 41 references. (JFP)

  18. Novel three-nucleon-force terms in the three-nucleon system

    CERN Document Server

    Hüber, D; Nogga, A; Witala, H; Kolck, U V

    2001-01-01

    We include to specific three-nucleon-force terms of pion-range-short-range form in our momentum-space calculations for the three-nucleon continuum. These two terms are expected by chiral perturbation theory to be non-negligible. We study the effects of these terms in elastic neutron-deuteron scattering and pay special attention to the neutron vector-analyzing power A sub y. (author)

  19. A novel poly(deep eutectic solvent)-based magnetic silica composite for solid-phase extraction of trypsin

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Kaijia [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Li, Yixue; Lin, Yunxuan; Zhang, Haibao [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Zhou, Yigang [Department of Microbiology, College of Basic Medicine, Central South University, Changsha, 410083 (China)

    2016-11-23

    Novel poly(deep eutectic solvent) grafted silica-coated magnetic microspheres (Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES) were prepared by polymerization of choline chloride-itaconic acid (ChCl-IA) and γ-MPS-modified magnetic silica composites, and were characterized by vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectra (XPS), thermal gravimetric analysis (TGA) and transmission electron microscope (TEM). Then the synthetic Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES microspheres were applied for the magnetic solid-phase extraction (MSPE) of trypsin for the first time. After extraction, the concentration of trypsin in the supernatant was determined by a UV–vis spectrophotometer. Single factor experiments were carried out to investigate the effects of the extraction process, including the concentration of trypsin, the ionic strength, the pH value, the extraction time and the temperature. Experimental results showed the extraction capacity could reach up to 287.5 mg/g under optimized conditions. In comparison with Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS, Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES displayed higher extraction capacity and selectivity for trypsin. According to the regeneration studies, Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES microspheres can be recycled six times without significant loss of its extraction capacity, and retained a high extraction capacity of 233 mg/g after eight cycles. Besides, the activity studies also demonstrated that the activity of the extracted trypsin was well retained. Furthermore, the analysis of real sample revealed that the prepared magnetic microspheres can be used to purify trypsin in crude bovine pancreas extract. These results highlight the potential of the proposed Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES-MSPE method in separation of biomolecules. - Highlights: • A strategy for solid-phase extraction of trypsin based on poly(deep eutectic solvent) modified magnetic silica

  20. Measuring the magnetic-field-dependent chemical potential of a low-density three-dimensional electron gas in n -GaAs and extracting its magnetic susceptibility

    Science.gov (United States)

    Roy Choudhury, Aditya N.; Venkataraman, V.

    2016-01-01

    We report the magnetic-field-dependent shift of the electron chemical potential in bulk, n -type GaAs at room temperature. A transient voltage of ˜100 μ V was measured across a Au-Al2O3 -GaAs metal-oxide-semiconductor capacitor in a pulsed magnetic field of ˜6 T . Several spurious voltages larger than the signal that had plagued earlier researchers performing similar experiments were carefully eliminated. The itinerant magnetic susceptibility of GaAs is extracted from the experimentally measured data for four different doping densities, including one as low as 5 ×1015cm-3 . Though the susceptibility in GaAs is dominated by Landau-Peierls diamagnetism, the experimental technique demonstrated can be a powerful tool for extracting the total free carrier magnetization of any electron system. The method is also virtually independent of the carrier concentration and is expected to work better in the nondegenerate limit. Such experiments had been successfully performed in two-dimensional electron gases at cryogenic temperatures. However, an unambiguous report on having observed this effect in any three-dimensional electron gas has been lacking. We highlight the 50 year old literature of various trials and discuss the key details of our experiment that were essential for its success. The technique can be used to unambiguously yield only the itinerant part of the magnetic susceptibility of complex materials such as magnetic semiconductors and hexaborides, and thus shed light on the origin of ferromagnetism in such systems.

  1. Coupled-cluster calculations of nucleonic matter

    Science.gov (United States)

    Hagen, G.; Papenbrock, T.; Ekström, A.; Wendt, K. A.; Baardsen, G.; Gandolfi, S.; Hjorth-Jensen, M.; Horowitz, C. J.

    2014-01-01

    Background: The equation of state (EoS) of nucleonic matter is central for the understanding of bulk nuclear properties, the physics of neutron star crusts, and the energy release in supernova explosions. Because nuclear matter exhibits a finely tuned saturation point, its EoS also constrains nuclear interactions. Purpose: This work presents coupled-cluster calculations of infinite nucleonic matter using modern interactions from chiral effective field theory (EFT). It assesses the role of correlations beyond particle-particle and hole-hole ladders, and the role of three-nucleon forces (3NFs) in nuclear matter calculations with chiral interactions. Methods: This work employs the optimized nucleon-nucleon (NN) potential NNLOopt at next-to-next-to leading order, and presents coupled-cluster computations of the EoS for symmetric nuclear matter and neutron matter. The coupled-cluster method employs up to selected triples clusters and the single-particle space consists of a momentum-space lattice. We compare our results with benchmark calculations and control finite-size effects and shell oscillations via twist-averaged boundary conditions. Results: We provide several benchmarks to validate the formalism and show that our results exhibit a good convergence toward the thermodynamic limit. Our calculations agree well with recent coupled-cluster results based on a partial wave expansion and particle-particle and hole-hole ladders. For neutron matter at low densities, and for simple potential models, our calculations agree with results from quantum Monte Carlo computations. While neutron matter with interactions from chiral EFT is perturbative, symmetric nuclear matter requires nonperturbative approaches. Correlations beyond the standard particle-particle ladder approximation yield non-negligible contributions. The saturation point of symmetric nuclear matter is sensitive to the employed 3NFs and the employed regularization scheme. 3NFs with nonlocal cutoffs exhibit a

  2. Dispersive micro solid phase extraction of amantadine, rimantadine and memantine in chicken muscle with magnetic cation exchange polymer.

    Science.gov (United States)

    Chen, Dawei; Miao, Hong; Zhao, Yunfeng; Wu, Yongning

    2017-04-15

    This study demonstrated a novel dispersive micro solid phase extraction (DMSPE) method for extraction of adamantane drugs (amantadine, rimantadine and memantine) in chicken muscle. The adamantane drugs were extracted from chicken muscle using 1% acidic acetonitrile as extraction solvent. The cleanup of fatty matrices from analytes was achieved by the DMSPE technique using magnetic cation exchange polymer as adsorbent. In this procedure, the experimental parameters and conditions were optimized in detail for the improvement of extraction efficiency. The method showed low limit of detection of 0.03μg/kg and recoveries of the analytes ranged from 87.2% to 109.3% for adamantane drugs. The proposed DMSPE method proved to be simple, effective and suitable for the treatment of adamantane drugs in chicken muscle with a relatively shorter extraction time. Copyright © 2017. Published by Elsevier B.V.

  3. Computing the nucleon Dirac radius directly at $Q^2=0$

    CERN Document Server

    Hasan, Nesreen; Green, Jeremy; Krieg, Stefan; Meinel, Stefan; Negele, John; Pochinsky, Andrew; Syritsyn, Sergey

    2016-01-01

    We describe a lattice approach for directly computing momentum derivatives of nucleon matrix elements using the Rome method, which we apply to obtain the isovector magnetic moment and Dirac radius. We present preliminary results calculated at the physical pion mass using a 2HEX-smeared Wilson-clover action. For removing the effects of excited-state contamination, the calculations were done at three source-sink separations and the summation method was used.

  4. Electromagnetic Meson Production in the Nucleon Resonance Region

    Energy Technology Data Exchange (ETDEWEB)

    Volker Burkert; T.-S. H. Lee

    2004-10-01

    Recent experimental and theoretical advances in investigating electromagnetic meson production reactions in the nucleon resonance region are reviewed. The article gives a description of current experimental facilities with electron and photon beams and presents a unified derivation of most of the phenomenological approaches being used to extract the resonance parameters from the data. The analyses of {pi} and {eta} production data and the resulting transition form factors for the {Delta}(1232)P{sub 33}, N(1535)S{sub 11}, N(1440)P{sub 11}, and N(1520)D{sub 13} resonances are discussed in detail. The status of our understanding of the reactions with production of two pions, kaons, and vector mesons is also reviewed.

  5. Magnetic multiwall carbon nanotubes modified with dual hydroxy functional ionic liquid for the solid-phase extraction of protein.

    Science.gov (United States)

    Chen, Jing; Wang, Yuzhi; Huang, Yanhua; Xu, Kaijia; Li, Na; Wen, Qian; Zhou, Yigang

    2015-05-21

    A novel adsorbent based on silica-coated magnetic multiwall carbon nanotubes (MWCNTs) surface modified by dual hydroxy functional ionic liquid (FIL) ([OH]-FIL-m-MWCNTs@SiO2) has been designed and used for the purification of lysozyme (Lys) by magnetic solid-phase extraction (MSPE). Fourier transform infrared spectroscopy (FTIR), a vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were employed to characterize [OH]-FIL-m-MWCNTs@SiO2. After extraction, the concentration of Lys was determined by a UV-Vis spectrophotometer at 278 nm. A series of single-factor experiments were carried out to identify the optimal conditions of the extraction and the extraction amount could reach up to 94.6 mg g(-1). The RSD of the precision, the repeatability and the stability experiments were 0.37% (n = 3), 0.47% (n = 3) and 0.52% (n = 3), respectively. Comparison of [OH]-FIL-m-MWCNTs@SiO2 with silica-coated magnetic Fe3O4 (Fe3O4@SiO2), silica-coated magnetic multiwall carbon nanotubes (m-MWCNTs@SiO2) and alkyl quaternary ammonium ionic liquid-modified on m-MWCNTs@SiO2 was carried out by extracting Lys. The extraction of bovine serum albumin (BSA), trypsin (Try) and ovalbumin (OVA) was also done by the proposed method. Desorption of Lys was carried out by 0.005 mol L(-1) Na2HPO4-1 mol L(-1) NaCl as the eluent solution and the desorption ratio reached 91.6%. Nearly 97.8% of the [OH]-FIL-m-MWCNTs@SiO2 could be recovered from each run, and the extraction amount decreased less after five runs. The circular dichroism spectral experiment analysis indicated that the secondary structure of Lys was unchanged after extraction.

  6. Recycling polymer residues to synthesize magnetic nanocomposites for dispersive micro-solid phase extraction.

    Science.gov (United States)

    Ghambari, Hoda; Reyes-Gallardo, Emilia M; Lucena, Rafael; Saraji, Mohammad; Cárdenas, Soledad

    2017-08-01

    The ubiquitous presence of plastics, an obvious consequence of their usefulness and low price, has turned them into a problem of environmental and safety concern. The new plastic economy, an initiative recently launched by the World Economic Forum and Ellen MacArthur Foundation, with analytical support from McKinsey & Company, promotes a change in the use of plastic worldwide around three main pillars: redesign, reusing and recycling. Recycled plastics, with the aim of extending their life spam, can be used to synthesize materials for analytical purposes. In this article polystyrene (PS) trays, previously used for food packaging, are proposed as polymeric source for the synthesis of magnetic nanocomposites. The synthesis plays with the solubility of PS in different solvents in such a way that PS is gelated in the presence of cobalt ferrite nanoparticles which are finally embedded in the polymeric network. The extraction capability of the magnetic PS nanocomposite was evaluated using the determination of four parabens (methylparaben, ethylparaben, propylparaben and butylparaben) in water using liquid chromatography-tandem mass spectrometry as model analytical problem. Under the optimum conditions, limits of detection and quantification were in the range of 0.05-0.15 and 0.15-0.5ng/mL, respectively. The precisions, expressed as relative standard deviation (RSD), varied between 4.4% and 8.5% and the relative recoveries for analysis of the water samples were in the interval 81.2-104.5%. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Iron sulfide (troilite) inclusion extracted from Sikhote-Alin iron meteorite: Composition, structure and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Oshtrakh, M.I., E-mail: oshtrakh@gmail.com [Department of Physical Techniques and Devices for Quality Control, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Department of Experimental Physics, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Klencsár, Z. [Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, Budapest, 1117 (Hungary); Petrova, E.V.; Grokhovsky, V.I. [Department of Physical Techniques and Devices for Quality Control, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Chukin, A.V. [Department of Theoretical Physics and Applied Mathematics, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Shtoltz, A.K. [Department of Electrophysics, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Maksimova, A.A. [Department of Physical Techniques and Devices for Quality Control, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Felner, I. [Racah Institute of Physics, The Hebrew University, Jerusalem (Israel); Kuzmann, E.; Homonnay, Z. [Institute of Chemistry, Eötvös Loránd University, Budapest (Hungary); Semionkin, V.A. [Department of Physical Techniques and Devices for Quality Control, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Department of Experimental Physics, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation)

    2016-05-01

    Iron sulfide (troilite) inclusion extracted from Sikhote-Alin IIAB iron meteorite was examined for its composition, structure and magnetic properties by means of several complementary analytical techniques such as: powder X-ray diffractometry, scanning electron microscopy combined with energy-dispersive X-ray spectroscopy, magnetization measurements, ferromagnetic resonance spectroscopy and {sup 57}Fe Mössbauer spectroscopy with a high velocity resolution. The applied techniques consistently indicated the presence of daubréelite (FeCr{sub 2}S{sub 4}) as a minority phase beside troilite proper (FeS). As revealed by {sup 57}Fe Mössbauer spectroscopy, the Fe atoms in troilite were in different microenvironments associated with either the ideal FeS structure or that of a slightly iron deficient Fe{sub 1–x}S. Phase transitions of troilite were detected above room temperature by ferromagnetic resonance spectroscopy. A novel analysis of 295 and 90 K {sup 57}Fe Mössbauer spectra was carried out and the hyperfine parameters associated with the ideal structure of troilite were determined by considering the orientation of the hyperfine magnetic field in the eigensystem of the electric field gradient at the {sup 57}Fe nucleus. - Highlights: • The presence of daubréelite in iron sulfide inclusion in Sikhote-Alin iron meteorite. • The presence of the ideal FeS and iron deficient Fe{sub 1–x}S in iron sulfide inclusion. • New way of the iron sulfide Mössbauer spectrum approximation.

  8. Precision Measurements of the Nucleon Strange Form Factors at Q^2 ~0.1 GeV^2

    CERN Document Server

    Acha, A; Armstrong, D S; Arrington, J; Averett, T; Bailey, S L; Barber, J; Beck, A; Benaoum, H; Benesch, J; Bertin, P Y; Bosted, P; Butaru, F; Burtin, E; Cates, G D; Chao Yu Chiu; Chen, J P; Chudakov, E; Cisbani, E; Craver, B; Cusanno, F; De Leo, R; Decowski, P; Deur, A; Feuerbach, R J; Finn, J M; Frullani, S; Fuchs, S A; Fuoti, K; Gilman, R; Glesener, L E; Grimm, K; Grames, J M; Hansen, J O; Hansknecht, J; Higinbotham, D W; Holmes, R; Holmstrom, T; Ibrahim, H; De Jager, C W; Jiang, X; Katich, J; Kaufman, L J; Kelleher, A; King, P M; Kolarkar, A; Kowalski, S; Kuchina, E; Kumar, K S; Lagamba, L; La Violette, P; Le Rose, J; Lindgren, R A; Lhuillier, D; Liyanage, N; Margaziotis, D J; Markowitz, P; Meekins, D G; Meziani, Z E; Michaels, R; Moffit, B; Nanda, S; Nelyubin, V V; Otis, K; Paschke, K D; Phillips, S K; Poelker, M; Pomatsalyuk, R I; Potokar, M; Prok, Y; Puckett, A; Qian, Y; Qiang, Y; Reitz, B; Roche, J; Saha, A; Sawatzky, B; Singh, J; Slifer, K J; Sirca, S; Snyder, R; Solvignon, P; Souder, P A; Stutzman, M L; Subedi, R; Suleiman, R; Sulkosky, V; Tobias, W A; Ulmer, P E; Urciuoli, G M; Wang, K; Whitbeck, A; Wilson, R; Wojtsekhowski, B; Yao, H; Ye, Y; Zhan, X; Zheng, X; Zhou, S; Ziskin, V

    2006-01-01

    We report new measurements of the parity-violating asymmetry A_PV in elastic scattering of 3 GeV electrons off hydrogen and 4He targets with ~0.6 degrees. The 4He result is A_PV = (+6.40 +/- 0.23 (stat) +/- 0.12 (syst)) x10^-6. The hydrogen result is A_PV = (-1.58 +/- 0.12 (stat) +/- 0.04 (syst)) x10^-6. These results significantly improve constraints on the electric and magnetic strange form factors G_E^s and G_M^s. We extract G_E^s = 0.002 +/- 0.014 +/- 0.007 at = 0.077 GeV^2, and G_E^s + 0.09 G_M^s = 0.007 +/- 0.011 +/- 0.006 at = 0.109 GeV^2, providing new limits on the role of strange quarks in the nucleon charge and magnetization distributions.

  9. New model for nucleon generalized parton distributions

    Energy Technology Data Exchange (ETDEWEB)

    Radyushkin, Anatoly V. [JLAB, Newport News, VA (United States)

    2014-01-01

    We describe a new type of models for nucleon generalized parton distributions (GPDs) H and E. They are heavily based on the fact nucleon GPDs require to use two forms of double distribution (DD) representations. The outcome of the new treatment is that the usual DD+D-term construction should be amended by an extra term, {xi} E{sub +}{sup 1} (x,{xi}) which has the DD structure {alpha}/{beta} e({beta},{alpha}, with e({beta},{alpha}) being the DD that generates GPD E(x,{xi}). We found that this function, unlike the D-term, has support in the whole -1 <= x <= 1 region. Furthermore, it does not vanish at the border points |x|={xi}.

  10. Chiral extrapolations for nucleon electric charge radii

    CERN Document Server

    Hall, J M M; Young, R D

    2013-01-01

    Lattice simulations for the electromagnetic form factors of the nucleon yield insights into the internal structure of hadrons. The logarithmic divergence of the charge radius in the chiral limit poses an interesting challenge in achieving reliable predictions from finite-volume lattice simulations. Recent results near the physical pion mass are examined in order to confront the issue of how the chiral regime is approached. The electric charge radius of the nucleon presents a forum for achieving consistent finite-volume corrections. Newly-developed techniques within the framework of chiral effective field theory are used to achieve a robust extrapolation of the electric charge radius to the physical pion mass, and to infinite volume. The chiral extrapolations exhibit considerable finite-volume dependence; lattice box sizes of L > 7 fm are required in order to achieve a direct lattice simulation result within 2% of the infinite-volume value at the physical point. Predictions of the volume-dependence are provide...

  11. The Form Factors of the Nucleons

    Energy Technology Data Exchange (ETDEWEB)

    Perdrisat, Charles F. [William and Mary College, JLAB

    2013-11-01

    There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has been greatly improved by performing double-polarization experiments, in comparison with with pre-vious unpolarized cross section data. Here we will review the experimental data base in view of the new results for the proton and the neutron, obtained at MIT-Bates, JLab and MAMI. The rapid evolution of phenomenological models triggered by these high- precision experiments will be discussed. In particular, the possibility that the proton is non-spherical in its ground state, and that the transverse charge density are model in- dependently defined in the infinite momentum frame. Likewise, flavor decomposition of the nucleon form factors into dressed u and d quark form factors, may give information about the quark-diquark structure of the nucleon. The current proton radius "crisis" will also be discussed.

  12. Establishing a novel automated magnetic bead-based method for the extraction of DNA from a variety of forensic samples.

    Science.gov (United States)

    Witt, Sebastian; Neumann, Jan; Zierdt, Holger; Gébel, Gabriella; Röscheisen, Christiane

    2012-09-01

    Automated systems have been increasingly utilized for DNA extraction by many forensic laboratories to handle growing numbers of forensic casework samples while minimizing the risk of human errors and assuring high reproducibility. The step towards automation however is not easy: The automated extraction method has to be very versatile to reliably prepare high yields of pure genomic DNA from a broad variety of sample types on different carrier materials. To prevent possible cross-contamination of samples or the loss of DNA, the components of the kit have to be designed in a way that allows for the automated handling of the samples with no manual intervention necessary. DNA extraction using paramagnetic particles coated with a DNA-binding surface is predestined for an automated approach. For this study, we tested different DNA extraction kits using DNA-binding paramagnetic particles with regard to DNA yield and handling by a Freedom EVO(®)150 extraction robot (Tecan) equipped with a Te-MagS magnetic separator. Among others, the extraction kits tested were the ChargeSwitch(®)Forensic DNA Purification Kit (Invitrogen), the PrepFiler™Automated Forensic DNA Extraction Kit (Applied Biosystems) and NucleoMag™96 Trace (Macherey-Nagel). After an extensive test phase, we established a novel magnetic bead extraction method based upon the NucleoMag™ extraction kit (Macherey-Nagel). The new method is readily automatable and produces high yields of DNA from different sample types (blood, saliva, sperm, contact stains) on various substrates (filter paper, swabs, cigarette butts) with no evidence of a loss of magnetic beads or sample cross-contamination. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  13. Nucleon and delta masses in QCD

    OpenAIRE

    Rafecas López, María Magdalena; Vento Torres, Vicente

    1992-01-01

    Using the positivity of the path integral measure of $QCD$ and defining a structure for the quark propagator in a background field according to the fluxon scenario for confinement, we calculate and compare the correlators for nucleon and delta. From their shape we elucidate about the origin of their mass difference, which in our simplified scenario is due to the tensor structure in the propagator. This term arises due to a dynamical mechanism which is responsible simultaneously for confinemen...

  14. Threshold segmentation algorithm for automatic extraction of cerebral vessels from brain magnetic resonance angiography images.

    Science.gov (United States)

    Wang, Rui; Li, Chao; Wang, Jie; Wei, Xiaoer; Li, Yuehua; Zhu, Yuemin; Zhang, Su

    2015-02-15

    Cerebrovascular segmentation plays an important role in medical diagnosis. This study was conducted to develop a threshold segmentation algorithm for automatic extraction and volumetric quantification of cerebral vessels on brain magnetic resonance angiography (MRA) images. The MRA images of 10 individuals were acquired using a 3 Tesla MR scanner (Intera-achieva SMI-2.1, Philips Medical Systems). Otsu's method was used to divide the brain MRA images into two parts, namely, foreground and background regions. To extract the cerebral vessels, we performed the threshold segmentation algorithm on the foreground region by comparing two different statistical distributions. Automatically segmented vessels were compared with manually segmented vessels. Different similarity metrics were used to assess the changes in segmentation performance as a function of a weighted parameter w used in segmentation algorithm. Varying w from 2 to 100 resulted in a false positive rate ranging from 117% to 3.21%, and a false negative rate ranging from 8.23% to 28.97%. The Dice similarity coefficient (DSC), which reflected the segmentation accuracy, initially increased and then decreased as w increased. The suggested range of values for w is [10, 20] given that the maximum DSC (e.g., DSC=0.84) was obtained within this range. The performance of our method was validated by comparing with manual segmentation. The proposed threshold segmentation method can be used to accurately and efficiently extract cerebral vessels from brain MRA images. Threshold segmentation may be used for studies focusing on three-dimensional visualization and volumetric quantification of cerebral vessels. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Extra dimensions, SN1987a, and nucleon-nucleon scattering data

    Energy Technology Data Exchange (ETDEWEB)

    Christoph Hanhart; Daniel R. Phillips; Sanjay Reddy; Martin J. Savage

    2001-02-01

    One of the strongest constraints on the existence of large, compact, ''gravity-only'' dimensions comes from SN1987a. If the rate of energy loss into these putative extra dimensions is too high, then the neutrino pulse from the supernova will differ from that actually seen. The dominant mechanism for the production of Kaluza-Klein gravitons and dilatons in the supernova is via gravistrahlung and dilastrahlung from the nucleon-nucleon system. In this paper we compute the rates for these processes in a model-independent way using low-energy theorems which relate the emissivities to the measured nucleon-nucleon cross section. This is possible because for soft gravitons and dilatons the leading contribution to the energy-loss rate is from graphs in which the gravitational radiation is produced from external nucleon legs. Previous calculations neglected these mechanisms. We re-evaluate the bounds on toroidally-compactified ''gravity-only'' dimensions (GODs), and find that consistency with the observed SN1987a neutrino signal requires that if there are two such dimensions then their radius must be less than 1 micron.

  16. Fe(3)O(4)@MOF core-shell magnetic microspheres for magnetic solid-phase extraction of polychlorinated biphenyls from environmental water samples.

    Science.gov (United States)

    Chen, Xiangfeng; Ding, Ning; Zang, Hao; Yeung, Hoisze; Zhao, Ru-Song; Cheng, Chuange; Liu, Jianhua; Chan, T-W Dominic

    2013-08-23

    Fe3O4@MIL-100 core-shell magnetic microspheres were, for the first time, used as the sorbent for the magnetic solid-phase extraction (MSPE) of polychlorinated biphenyls at trace levels in environmental water samples. GC coupled with tandem MS was used for sample quantification and detection. The Box-Behnken design was used to determine the optimum extraction parameters influencing extraction efficiency through response surface methodology. Under the optimized conditions, the developed method showed good linearity within the range of 5-4000ngL(-1), low limits of detection (1.07-1.57ngL(-1); signal-to-noise ratio=3:1), and good extraction repeatability (relative standard deviationsnow water were processed using the developed method. The results demonstrated that the Fe3O4@MOF core-shell magnetic microspheres are promising sorbents in the MSPE of aromatic pollutants from environmental water samples. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Nucleon localization within nuclear density functional theory

    Science.gov (United States)

    Zhang, Chunli; Schuetrumpf, Bastian; Nazarewicz, Witold

    2016-09-01

    Recently, a nucleon localization measure based on Hartree-Fock densities has been introduced to investigate α-cluster structures in light nuclei. Compared to the local nucleonic density, the nucleon localization function (NLF) has been shown to be an excellent indicator of cluster correlations. To investigate the cluster structures in light nuclei and study the development of fission fragments in heavy nuclei, we analyse NLFs in deformed nuclei. We use both the deformed harmonic oscillator model and self-consistent nuclear density functional theory (DFT) with energy density functionals UNEDF1 and UNEDF1-HFB, which were optimized for fission studies. In this contribution, we will discuss particle densities and spatial localization functions for deformed configurations of 8Be and 20Ne and along fission pathways of 232Th and 240Pu. We illustrate the usefulness of the NLF by showing how the third hyperdeformed minimum of 232Th can be understood in terms of the ground states of 132Sn and 100Zr. This material is based upon work supported by the U.S. Department of Energy, Office of Science under Award Numbers DOE-DE-NA0002847, DE-SC0013365 (Michigan State University), and DE-SC0008511 (NUCLEI SciDAC-3 collaboration).

  18. Nuclear matter saturation with chiral three-nucleon interactions fitted to light nuclei properties

    Energy Technology Data Exchange (ETDEWEB)

    Logoteta, Domenico [INFN, Sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy); Bombaci, Ignazio, E-mail: ignazio.bombaci@unipi.it [Dipartimento di Fisica, Universitá di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy); INFN, Sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy); European Gravitational Observatory, Via E. Amaldi, I-56021 S. Stefano a Macerata, Cascina (Italy); Kievsky, Alejandro [INFN, Sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy)

    2016-07-10

    The energy per particle of symmetric nuclear matter and pure neutron matter is calculated using the many-body Brueckner–Hartree–Fock approach and employing the Chiral Next-to-next-to-next-to leading order (N3LO) nucleon–nucleon (NN) potential, supplemented with various parametrizations of the Chiral Next-to-next-to leading order (N2LO) three-nucleon interaction. Such combination is able to reproduce several observables of the physics of light nuclei for suitable choices of the parameters entering in the three-nucleon interaction. We find that some of these parametrizations provide a satisfactory saturation point of symmetric nuclear matter and values of the symmetry energy and its slope parameter L in very good agreement with those extracted from various nuclear experimental data. Thus, our results represent a significant step toward a unified description of few- and many-body nuclear systems starting from two- and three-nucleon interactions based on the symmetries of QCD.

  19. Charmonium-nucleon interaction from lattice QCD with a relativistic heavy quark action

    CERN Document Server

    Kawanai, Taichi

    2010-01-01

    Detailed information of the low-energy interaction between the charmonia ({\\eta}c and J/{\\psi}) and the nucleon is indispensable for exploring the formation of charmonium bound to nuclei. In order to investigate the charmonium-nucleon interactions at low energies, we adopt two essentially different approaches in lattice QCD simulations. The charmonium-nucleon potential can be calculated from the equal-time Bethe-Salpeter amplitude through the effective Schr\\"odinger equation. This novel method is based on the same idea originally applied for the nucleon force by Aoki- Hatsuda-Ishii. Another approach is to utilize extended L\\"uscher’s formula with partially twisted boundary conditions, which allows us to calculate the s-wave phase shift at any small value of the relative momentum even in a finite box. We then extract model independent information of the scattering length and the effective range from the phase shift through the effective-range expansion. Our simulations are carried out at a lattice cutoff ...

  20. Amphiphilic block copolymer modified magnetic nanoparticles for microwave-assisted extraction of polycyclic aromatic hydrocarbons in environmental water.

    Science.gov (United States)

    Li, Nan; Qi, Li; Shen, Ying; Li, Yaping; Chen, Yi

    2013-11-05

    In this work, amphiphilic block copolymer poly(tert-butyl methacrylate)-block-poly(glycidyl methacrylate) (PtBMA-b-PGMA) modified Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) were synthesized, and served as an adsorbent for microwave-assisted extraction of polycyclic aromatic hydrocarbons (PAHs). The PtBMA-b-PGMA block copolymers with different block ratios were prepared by two-step atom transfer radical polymerization (ATRP) and the extraction abilities of their corresponding Fe3O4@PtBMA-b-PGMA were investigated. The key factors affecting the extraction efficiency of the adsorbent, including microwave conditions, amount of adsorbent, type and volume of desorption solvent, were studied in detail. In comparison with vortex, which is a conventional method used for assisting extraction, the proposed microwave-assisted method allowed better extraction efficiency and required a shorter extraction time. The calibration curves of PAHs were obtained in the range of 0.05-120 μg/L (r>0.9985) and the limits of detection (S/N=3) were in the range of 2.4-6.3 ng/L. The recoveries of PAHs spiked in environmental water samples were between 62.5% and 104% with relative standard deviations (RSDs) ranging from 0.84% to 9.02%. The proposed technique combining microwave-assisted extraction and magnetic separation was demonstrated to be a fast, convenient and sensitive pretreating method for PAHs. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Parity violation in neutron capture on the proton: Determining the weak pion–nucleon coupling

    Directory of Open Access Journals (Sweden)

    J. de Vries

    2015-07-01

    Full Text Available We investigate the parity-violating analyzing power in neutron capture on the proton at thermal energies in the framework of chiral effective field theory. By combining this analysis with a previous analysis of parity violation in proton–proton scattering, we are able to extract the size of the weak pion–nucleon coupling constant. The uncertainty is significant and dominated by the experimental error which is expected to be reduced soon.

  2. Dynamical Coupled-Channel Model of Meson Production Reactions in the Nucleon Resonance Region

    Energy Technology Data Exchange (ETDEWEB)

    T.-S. H. Lee; A. Matsuyama; T. Sato

    2006-11-15

    A dynamical coupled-channel model is presented for investigating the nucleon resonances (N*) in the meson production reactions induced by pions and photons. Our objective is to extract the N* parameters and to investigate the meson production reaction mechanisms for mapping out the quark-gluon substructure of N* from the data. The model is based on an energy-independent Hamiltonian which is derived from a set of Lagrangians by using a unitary transformation method.

  3. Reevaluation of the Parton Distribution of Strange Quarks in the Nucleon

    CERN Document Server

    Airapetian, A; Akopov, Z; Aschenauer, E C; Augustyniak, W; Avetissian, A; Avetisyan, E; Belostotski, S; Blok, H P; Borissov, A; Bryzgalov, V; Burns, J; Capiluppi, M; Capitani, G P; Cisbani, E; Ciullo, G; Contalbrigo, M; Dalpiaz, P F; Deconinck, W; De Leo, R; De Sanctis, E; Diefenthaler, M; Di Nezza, P; Düren, M; Ehrenfried, M; Elbakian, G; Ellinghaus, F; Etzelmüller, E; Felawka, L; Frullani, S; Gabbert, D; Gapienko, G; Gapienko, V; García, J Garay; Garibaldi, F; Gavrilov, G; Gharibyan, V; Giordano, F; Gliske, S; Hartig, M; Hasch, D; Hoek, M; Holler, Y; Hristova, I; Jackson, H E; Joosten, S; Kaiser, R; Karyan, G; Keri, T; Kinney, E; Kisselev, A; Korotkov, V; Kozlov, V; Kravchenko, P; Krivokhijine, V G; Lagamba, L; Lapikás, L; Lehmann, I; Lenisa, P; Lorenzon, W; Ma, B -Q; Mahon, D; Manaenkov, S I; Mao, Y; Marianski, B; Marukyan, H; Miyachi, Y; Movsisyan, A; Muccifora, V; Murray, M; Mussgiller, A; Naryshkin, Y; Nass, A; Negodaev, M; Nowak, W -D; Pappalardo, L L; Perez-Benito, R; Petrosyan, A; Reimer, P E; Reolon, A R; Riedl, C; Rith, K; Rosner, G; Rostomyan, A; Rubin, J; Ryckbosch, D; Salomatin, Y; Schäfer, A; Schnell, G; Seitz, B; Shibata, T -A; Stahl, M; Statera, M; Steffens, E; Steijger, J J M; Stinzing, F; Taroian, S; Terkulov, A; Truty, R; Trzcinski, A; Tytgat, M; Van Haarlem, Y; Van Hulse, C; Veretennikov, D; Vikhrov, V; Vilardi, I; Vogel, C; Wang, S; Yaschenko, S; Ye, Z; Yen, S; Zihlmann, B; Zupranski, P

    2013-01-01

    An earlier extraction from the HERMES experiment of the polarization-averaged parton distribution of strange quarks in the nucleon has been reevaluated using final data on the multiplicities of charged kaons in semi-inclusive deep-inelastic scattering obtained with a kinematically more comprehensive method of correcting for experimental effects. General features of the distribution are confirmed, but the rise at low $x$ is less pronounced than previously reported.

  4. Preparation of magnetic molecularly imprinted polymers by atom transfer radical polymerization for the rapid extraction of avermectin from fish samples.

    Science.gov (United States)

    You, Xiaoxiao; Gao, Lei; Qin, Dongli; Chen, Ligang

    2017-01-01

    A novel and highly efficient approach to obtain magnetic molecularly imprinted polymers is described to detect avermectin in fish samples. The magnetic molecularly imprinted polymers were synthesized by surface imprinting polymerization using magnetic multiwalled carbon nanotubes as the support materials, atom transfer radical polymerization as the polymerization method, avermectin as template, acrylamide as functional monomer, and ethylene glycol dimethacrylate as crosslinker. The characteristics of the magnetic molecularly imprinted polymers were assessed by using transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, vibrating sample magnetometry, X-ray diffraction, and thermogravimetric analysis. The binding characteristics of magnetic molecularly imprinted polymers were researched through isothermal adsorption experiment, kinetics adsorption experiment, and the selectivity experiment. Coupled with ultra high performance liquid chromatography and tandem mass spectrometry, the extraction conditions of the magnetic molecularly imprinted polymers as adsorbents for avermectin were investigated in detail. The recovery of avermectin was 84.2-97.0%, and the limit of detection was 0.075 μg/kg. Relative standard deviations of intra- and inter-day precisions were in the range of 1.7-2.9% and 3.4-5.6%, respectively. The results demonstrated that the extraction method not only has high selectivity and accuracy, but also is convenient for the determination of avermectin in fish samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Direct Drive and Eddy Current Septa Magnet Designs for CERN’s PSB Extraction at 2 GeV

    CERN Multimedia

    Szoke, Zsolt; Balhan, Bruno; Baud, Cedric; Borburgh, Jan; Hourican, Michael; Masson, Thierry; Prost, Antoine

    2015-01-01

    In the framework of the LIU project, new septa magnets have been designed between CERN’s PS Booster (PSB) extraction and PS injection. The upgraded devices are to deal with the increased beam energy from 1.4 GeV to 2 GeV at extraction of the PSB. The direct drive recombination septa in the PSB transfer line to the PS, the eddy current PS injection septum together with a bumper at injection have been investigated using finite element software. For the recombination magnets an increase in magnet length is sufficient to obtain the required deflection; however, for the PS injection elements a more novel solution is necessary to also achieve increased robustness to extend the expected lifetime of the pulsed device. The injection septum will share the same vacuum vessel with an injection bumper and both magnets will be located adjacent to each other. The new PS injection magnet will be the first septum operated at CERN based on eddy current technology. The magnetic modelling of the devices, the comparison of the ...

  6. submitter Direct Drive and Eddy Current Septa Magnet Designs for CERN's PSB Extraction at 2 GeV

    CERN Document Server

    Szoke, Z; Balhan, B; Baud, C; Borburgh, J; Hourican, M; Masson, T; Prost, A

    2016-01-01

    In the framework of the LIU project, new septa magnets have been designed between CERN's PS booster (PSB) extraction and PS injection. The upgraded devices are to deal with the increased beam energy from 1.4 to 2 GeV at extraction of the PSB. The direct drive recombination septa in the PSB transfer line to the PS and the eddy current PS injection septum together with a bumper at injection have been investigated using finite-element software. For the recombination magnets, an increase in magnet length is sufficient to obtain the required deflection; however, for the PS injection elements, a more novel solution is necessary to also achieve increased robustness to extend the expected lifetime of the pulsed device. The injection septum will share the same vacuum vessel with an injection bumper, and both magnets will be located adjacent to each other. The new PS injection magnet will be the first septum operated at CERN based on eddy current technology. The magnetic modeling of the devices, the comparison of the p...

  7. Nucleon-nucleon dynamics at medium energies (I). Unitary model for elastic and inelastic scattering

    Science.gov (United States)

    Kloet, W. M.; Silbar, Richard R.

    1980-04-01

    A framework is presented for a unified theory of elastic nucleon-nucleon scattering and single-pion production at medium energies. The model is relativistic, unitary, and takes into account all spin complications. In the simplest version of the theory the driving mechanism is one-pion exchange but the model can be extended to include short-range forces. The resulting set of coupled linear integral equations have the structure of three-body equations and can be solved exactly. The method of solution is discussed.

  8. Nucleon-nucleon dynamics at medium energies (II). Results for NN phase parameters

    Science.gov (United States)

    Silbar, Richard R.; Kloet, W. M.

    1980-04-01

    We present predictions for nucleon-nucleon elastic scattering phase parameters based on a unitary, relativistic, one-pion-exchange model, which takes single-pion-production inelasticity into account. The agreement of the high- L phase shifts with data is considerably improved at intermediate energies by inclusion of the NΔ inelastic channel. Our predicted inelasticities are in generally good agreement with the data, but are smaller than the predictions of Green and Sainio. The Argand plots of the 1D 2, 3F 3, 3P 1, and 1G 4 all show counterclockwise motion resulting from the onset of inelastic channels.

  9. High energy nucleonic component of cosmic rays at mountain altitudes

    CERN Document Server

    Stora, Raymond Félix

    The diffusion equations describing the unidimensional propagation of .the high energy nucleonic component of cosmic rays throughout the atmosphere are sol"V'ed under two assumptions: (l) The nucleon-nucleon collisions are described according to Fermi's therlnOdynamical model involving completely inelastic pion and.nucleon-antinucleon pair production. (2) A somewhat opposite assumption is made assuming partially elastic collisions without nucleon-anti.nucleon pair production. Due to the present inaccuracy of experiments, we are able to derive only tentati v.e conclusions. The values computed under both hypotheses for the absorption mean free path and the charged to neutral particles ratio are found in acceptable ranges when compared to experimental data. The diffeential energy spectrum at a given depth is always found steeper than the primary, and steeper than indicated by experimental values if the primary is taken proportional to the 2.5 inverse power of energy.

  10. Analysis of the quadrupole deformation of {delta}(1232) within an effective Lagrangian model for pion photoproduction from the nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Ramirez, C. [CSIC, Instituto de Estructura de la Materia, Madrid (Spain); Universidad de Sevilla, Departamento de Fisica Atomica, Molecular y Nuclear, Sevilla (Spain); Moya de Guerra, E. [CSIC, Instituto de Estructura de la Materia, Madrid (Spain); Universidad Complutense de Madrid, Departamento de Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Madrid (Spain); Udias, J.M. [Universidad Complutense de Madrid, Departamento de Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Madrid (Spain)

    2007-03-15

    We present an extraction of the E2/M1 ratio of the {delta}(1232) from experimental data applying an effective Lagrangian model. We compare the result obtained with different nucleonic models and we reconcile the experimental results with the lattice QCD calculations. (orig.)

  11. Nucleon electromagnetic structure studies in the spacelike and timelike regions

    Energy Technology Data Exchange (ETDEWEB)

    Guttmann, Julia

    2013-07-23

    The thesis investigates the nucleon structure probed by the electromagnetic interaction. One of the most basic observables, reflecting the electromagnetic structure of the nucleon, are the form factors, which have been studied by means of elastic electron-proton scattering with ever increasing precision for several decades. In the timelike region, corresponding with the proton-antiproton annihilation into a electron-positron pair, the present experimental information is much less accurate. However, in the near future high-precision form factor measurements are planned. About 50 years after the first pioneering measurements of the electromagnetic form factors, polarization experiments stirred up the field since the results were found to be in striking contradiction to the findings of previous form factor investigations from unpolarized measurements. Triggered by the conflicting results, a whole new field studying the influence of two-photon exchange corrections to elastic electron-proton scattering emerged, which appeared as the most likely explanation of the discrepancy. The main part of this thesis deals with theoretical studies of two-photon exchange, which is investigated particularly with regard to form factor measurements in the spacelike as well as in the timelike region. An extraction of the two-photon amplitudes in the spacelike region through a combined analysis using the results of unpolarized cross section measurements and polarization experiments is presented. Furthermore, predictions of the two-photon exchange effects on the e{sup +}p/e{sup -}p cross section ratio are given for several new experiments, which are currently ongoing. The two-photon exchange corrections are also investigated in the timelike region in the process p anti p → e{sup +}e{sup -} by means of two factorization approaches. These corrections are found to be smaller than those obtained for the spacelike scattering process. The influence of the two-photon exchange corrections on

  12. Proceedings of RIKEN BNL Research Center Workshop: Brookhaven Summer Program on Nucleon Spin Physics

    Energy Technology Data Exchange (ETDEWEB)

    Aschenauer, A.; Qiu, Jianwei; Vogelsang, W.; Yuan, F.

    2011-08-02

    Understanding the structure of the nucleon is of fundamental importance in sub-atomic physics. Already the experimental studies on the electro-magnetic form factors in the 1950s showed that the nucleon has a nontrivial internal structure, and the deep inelastic scattering experiments in the 1970s revealed the partonic substructure of the nucleon. Modern research focuses in particular on the spin and the gluonic structure of the nucleon. Experiments using deep inelastic scattering or polarized p-p collisions are carried out in the US at the CEBAF and RHIC facilities, respectively, and there are other experimental facilities around the world. More than twenty years ago, the European Muon Collaboration published their first experimental results on the proton spin structure as revealed in polarized deep inelastic lepton-nucleon scattering, and concluded that quarks contribute very little to the proton's spin. With additional experimental and theoretical investigations and progress in the following years, it is now established that, contrary to naive quark model expectations, quarks and anti-quarks carry only about 30% of the total spin of the proton. Twenty years later, the discovery from the polarized hadron collider at RHIC was equally surprising. For the phase space probed by existing RHIC experiments, gluons do not seem to contribute any to the proton's spin. To find out what carries the remaining part of proton's spin is a key focus in current hadronic physics and also a major driving force for the new generation of spin experiments at RHIC and Jefferson Lab and at a future Electron Ion Collider. It is therefore very important and timely to organize a series of annual spin physics meetings to summarize the status of proton spin physics, to focus the effort, and to layout the future perspectives. This summer program on 'Nucleon Spin Physics' held at Brookhaven National Laboratory (BNL) on July 14-27, 2010 [http://www.bnl.gov/spnsp/] is the

  13. Nucleon polarizabilities: From Compton scattering to hydrogen atom

    OpenAIRE

    Hagelstein, Franziska; Miskimen, Rory; Pascalutsa, Vladimir

    2016-01-01

    We review the current state of knowledge of the nucleon polarizabilities and of their role in nucleon Compton scattering and in hydrogen spectrum. We discuss the basic concepts, the recent lattice QCD calculations and advances in chiral effective-field theory. On the experimental side, we review the ongoing programs aimed to measure the nucleon (scalar and spin) polarizabilities via the Compton scattering processes, with real and virtual photons. A great part of the review is devoted to the g...

  14. Restricted access magnetic materials prepared by dual surface modification for selective extraction of therapeutic drugs from biological fluids

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yu; Wang Yuxia; Chen Lei [School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072 (China); Wan Qianhong, E-mail: qhwan@tju.edu.cn [School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072 (China)

    2012-02-15

    Magnetic porous particles with dual functionality have been prepared by a two-step procedure and evaluated as novel restricted access materials for extraction of therapeutic agents from biological fluids. The magnetic silica particles served as scaffolds were first modified with diol groups, which were then converted to octadecyl esters through reaction with stearoyl chloride. In the second step, the octadecyl esters on the exterior surface were hydrolyzed by the action of lipase to yield magnetic particles with hydrophobic reversed-phase ligands on the inner surface and biocompatible diol groups on the outer surface. The restricted access behavior of the resulting materials was confirmed by differential binding of small molecules such as methotrexate (MTX), leucovorin (LV) and folic acid (FA) relative to bovine serum albumin. While MTX, LV and FA were all bound to the magnetic particles with high affinity, the adsorption of the protein was markedly reduced due to size exclusion effect. The utility of the magnetic particles for sample preparation was tested in solid-phase extraction of MTX, LV and FA from spiked human serum and the effects of the SPE conditions on the recovery of the analytes were systematically studied. Moreover, the magnetic particle-based sample preparation procedure coupled with reversed-phase liquid chromatography analysis was validated in terms of specificity, linearity and reproducibility. The method was shown to be free from interference of endogenous compounds and linear over the concentration range of 0.5-10 {mu}g/mL for the three drugs studied. The limits of detection for the three drugs in serum were in the range of 0.160-0.302 {mu}g/mL. Reproducibility expressed as the RSD of the recovery for ten replicated extractions at three different concentrations was found to be less than 8.93%. With a unique combination of surface functionality with magnetic cores, the restricted access magnetic particles may be adapted in automated and high

  15. One pot synthesis of magnetic graphene/carbon nanotube composites as magnetic dispersive solid-phase extraction adsorbent for rapid determination of oxytetracycline in sewage water.

    Science.gov (United States)

    Sun, Yunyun; Tian, Jing; Wang, Lu; Yan, Hongyuan; Qiao, Fengxia; Qiao, Xiaoqiang

    2015-11-27

    A simple and time-saving one pot synthesis of magnetic graphene/carbon nanotube composites (M-G/CNTs) was developed that could avoid the tedious drying process of graphite oxide, and G/CNTs were modified by Fe3O4 nanoparticles in the reduction procedure. It contributed to a shorten duration of the synthesis process of M-G/CNTs. The obtained M-G/CNTs were characterized and the results indicated that CNTs and Fe3O4 nanoparticles were served as spacer distributing to the layers of graphene, which was beneficial for enlarging surface area and improving extraction efficiency. Moreover, M-G/CNTs showed good magnetic property and outstanding thermal stability. Then M-G/CNTs were applied as adsorbent of magnetic dispersive solid-phase extraction for rapid extraction and determination of oxytetracycline in sewage water. Under the optimum conditions, good linearity was obtained in the range of 20-800ngmL(-1) and the recoveries were ranged from 95.5% to 112.5% with relative standard deviations less than 5.8%. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Magnetic solid-phase extraction of phthalate esters (PAEs) in apparel textile by core-shell structured Fe3O4@silica@triblock-copolymer magnetic microspheres.

    Science.gov (United States)

    Xu, Mei; Liu, Minhua; Sun, Meirong; Chen, Kun; Cao, Xiujun; Hu, Yaoming

    2016-04-01

    In this paper, novel core-shell structured magnetic Fe3O4/silica nanocomposites with triblock-copolymer grafted on their surface (Fe3O4@SiO2@MDN) were successfully fabricated by combining a sol-gel method with a seeded aqueous-phase radical copolymerization approach. Owing to the excellent characteristics of the strong magnetic responsivity, outstanding hydrophilicity and abundant π-electron system, the obtained core-shell structured microspheres showed great potential as a magnetic solid phase extraction (MSPE) adsorbent. Several kinds of phthalate esters (PAEs) were selected as model analytes to systematically evaluate the applicability of adsorbents for extraction followed by gas chromatography-mass spectrometry (GC-MS) analyses. Various parameters, including adsorbents amounts, adsorption time, species of eluent, and desorption time were optimized. Under the optimized conditions, Validation experiments such as recovery, reproducibility, and limit of detection were carried on and showed satisfactory results. The analysis method showed excellent linearity with a wide range of 0.2-10mg/kg (R(2)>0.9974) and low limits of detection (LOD) of 0.02-0.09 mg/kg (S/N=3). Ultimately, the novel magnetic adsorbents were successfully employed to detect the PAEs in apparel textile samples. And the results indicated that this novel approach brought forward in the present work offered an attractive alternative for rapid, efficient and sensitive MSPE for PAEs compounds. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Photoproduction de Mesons sur le Nucleon aux Energies Intermediaire (in French) [Photoproduction of mesons on the nucleon at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Guidal, Michel [Univ. of Paris, Orsay (France)

    1996-12-13

    One object of this thesis is to propose a model taking account of low transfer reaction mechanisms for a series of photoproduction reactions on nucleons for photon energies ≳4 GeV. If our comprehension of processes with low transfers is correct, then extrapolating our model in the domain of large transfers and the comparison with data supplied will give us information on the domains in energy and transfers from which an interpretation of reactions in terms of the "soft" process ceases to be valid. In the domain of large transfers, only one approach in terms of "hard" process can then explain the data. We are interested in electromagnetic photoproduction reactions because the probe, firstly, interacts with the target via an exact and well known mechanism (described by the QED theory) and also eliminates the interaction phenomena in the initial state. No probe is as well known as the photon. The extraction of reaction mechanisms, amplitudes and coupling constants match is made easier than in the case of hadronic probes. The energy domain Eγ >4 GeV studied is particularly interesting because it is from this energy of incident photons that can be expected to achieve large enough pulse transfers to hope for emergence of hard processes and therefore see the cessation of validity of interpretation of hadron models. Also, resonance effects are minor and do not interfere with our interpretations. Experimentally, this area is widely unexplored and the new generation accelerators of a large duty cycle (CEBAF, MAMI, ESRF, ELF, ...) combined with 4π detectors will allow to precisely measure low cross sections reactions of a large transfer. We first study pion photoproduction reactions on nucleon because they are the most experimentally accessible reactions and many data of high energy and low transfers exist. This will require strong constraints on the model parameters of the numerous analyses performed previously. Then we'll move on to kaon photoproduction

  18. Evaluation of Superparamagnetic Silica Nanoparticles for Extraction of Triazines in Magnetic in-Tube Solid Phase Microextraction Coupled to Capillary Liquid Chromatography

    Science.gov (United States)

    González-Fuenzalida, R. A.; Moliner-Martínez, Y.; Prima-Garcia, Helena; Ribera, Antonio; Campins-Falcó, P.; Zaragozá, Ramon J.

    2014-01-01

    The use of magnetic nanomaterials for analytical applications has increased in the recent years. In particular, magnetic nanomaterials have shown great potential as adsorbent phase in several extraction procedures due to the significant advantages over the conventional methods. In the present work, the influence of magnetic forces over the extraction efficiency of triazines using superparamagnetic silica nanoparticles (NPs) in magnetic in tube solid phase microextraction (Magnetic-IT-SPME) coupled to CapLC has been evaluated. Atrazine, terbutylazine and simazine has been selected as target analytes. The superparamagnetic silica nanomaterial (SiO2-Fe3O4) deposited onto the surface of a capillary column gave rise to a magnetic extraction phase for IT-SPME that provided a enhancemment of the extraction efficiency for triazines. This improvement is based on two phenomena, the superparamegnetic behavior of Fe3O4 NPs and the diamagnetic repulsions that take place in a microfluidic device such a capillary column. A systematic study of analytes adsorption and desorption was conducted as function of the magnetic field and the relationship with triazines magnetic susceptibility. The positive influence of magnetism on the extraction procedure was demonstrated. The analytical characteristics of the optimized procedure were established and the method was applied to the determination of the target analytes in water samples with satisfactory results. When coupling Magnetic-IT-SPME with CapLC, improved adsorption efficiencies (60%–63%) were achieved compared with conventional adsorption materials (0.8%–3%). PMID:28344221

  19. Evaluation of Superparamagnetic Silica Nanoparticles for Extraction of Triazines in Magnetic in-Tube Solid Phase Microextraction Coupled to Capillary Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    R. A. González-Fuenzalida

    2014-04-01

    Full Text Available The use of magnetic nanomaterials for analytical applications has increased in the recent years. In particular, magnetic nanomaterials have shown great potential as adsorbent phase in several extraction procedures due to the significant advantages over the conventional methods. In the present work, the influence of magnetic forces over the extraction efficiency of triazines using superparamagnetic silica nanoparticles (NPs in magnetic in tube solid phase microextraction (Magnetic-IT-SPME coupled to CapLC has been evaluated. Atrazine, terbutylazine and simazine has been selected as target analytes. The superparamagnetic silica nanomaterial (SiO2-Fe3O4 deposited onto the surface of a capillary column gave rise to a magnetic extraction phase for IT-SPME that provided a enhancemment of the extraction efficiency for triazines. This improvement is based on two phenomena, the superparamegnetic behavior of Fe3O4 NPs and the diamagnetic repulsions that take place in a microfluidic device such a capillary column. A systematic study of analytes adsorption and desorption was conducted as function of the magnetic field and the relationship with triazines magnetic susceptibility. The positive influence of magnetism on the extraction procedure was demonstrated. The analytical characteristics of the optimized procedure were established and the method was applied to the determination of the target analytes in water samples with satisfactory results. When coupling Magnetic-IT-SPME with CapLC, improved adsorption efficiencies (60%–63% were achieved compared with conventional adsorption materials (0.8%–3%.

  20. Complete Set of Deuteron Analyzing Powers for dp Elastic Scattering at 250 MeV/nucleon and Three Nucleon Forces

    Directory of Open Access Journals (Sweden)

    Shimizu Y.

    2010-04-01

    Full Text Available Measurements of a complete set of deuteron analyzing powers (iT11, T20, T21, T22 for elastic deuteron–proton scattering at 250 MeV/nucleon have been performed with polarized deuteron beams at RIKEN RI Beam Factory. The obtained data are compared with the Faddeev calculations based on the modern nucleon–nucleon forces together with the Tucson-Melbourne’99, and UrbanaIX three nucleon forces.

  1. Magnetically-enabled biomarker extraction and delivery system: towards integrated ASSURED diagnostic tools.

    Science.gov (United States)

    Bauer, Westley S; Kimmel, Danielle W; Adams, Nicholas M; Gibson, Lauren E; Scherr, Thomas F; Richardson, Kelly A; Conrad, Joseph A; Matakala, Hellen K; Haselton, Frederick R; Wright, David W

    2017-05-02

    Diagnosis of asymptomatic malaria poses a great challenge to global disease elimination efforts. Healthcare infrastructure in rural settings cannot support existing state-of-the-art tools necessary to diagnose asymptomatic malaria infections. Instead, lateral flow immunoassays (LFAs) are widely used as a diagnostic tool in malaria endemic areas. While LFAs are simple and easy to use, they are unable to detect low levels of parasite infection. We have developed a field deployable Magnetically-enabled Biomarker Extraction And Delivery System (mBEADS) that significantly improves limits of detection for several commercially available LFAs. Integration of mBEADS with leading commercial Plasmodium falciparum malaria LFAs improves detection limits to encompass an estimated 95% of the disease reservoir. This user-centered mBEADS platform makes significant improvements to a previously cumbersome malaria biomarker enrichment strategy by improving reagent stability, decreasing the processing time 10-fold, and reducing the assay cost 10-fold. The resulting mBEADS process adds just three minutes and less than $0.25 to the total cost of a single LFA, thus balancing sensitivity and practicality to align with the World Health Organization's ASSURED criteria for point-of-care (POC) testing.

  2. Novel technique for injecting and extracting beams in a circular hadron accelerator without using septum magnets

    Directory of Open Access Journals (Sweden)

    Andrea Franchi

    2015-07-01

    Full Text Available With a few exceptions, all on-axis injection and extraction schemes implemented in circular particle accelerators, synchrotrons, and storage rings, make use of magnetic and electrostatic septa with systems of slow-pulsing dipoles acting on tens of thousands of turns and fast-pulsing dipoles on just a few. The dipoles create a closed orbit deformation around the septa, usually referred to as an orbit bump. A new approach is presented which obviates the need for the septum deflectors. Fast-pulsing elements are still required, but their strength can be minimized by choosing appropriate local accelerator optics. This technique should increase the beam clearance and reduce the usually high radiation levels found around the septa and also reduce the machine impedance introduced by the fast-pulsing dipoles. The basis of the technique is the creation of stable islands around stable fixed points in horizontal phase space. The trajectories of these islands may then be adjusted to match the position and angle of the incoming or outgoing beam.

  3. Magnetic graphene oxide modified with choline chloride-based deep eutectic solvent for the solid-phase extraction of protein

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yanhua; Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn; Pan, Qi; Wang, Ying; Ding, Xueqin; Xu, Kaijia; Li, Na; Wen, Qian

    2015-06-02

    Highlights: • A strategy for extraction of protein based on DES-coated magnetic graphene oxide. • The deep eutectic solvents were based on choline chloride. • Bovine serum albumin was used as the analyte. • The material prepared works for the acidic but not the basic or the neutral proteins. - Abstract: Four kinds of green deep eutectic solvents (DESs) based on choline chloride (ChCl) have been synthesized and coated on the surface of magnetic graphene oxide (Fe{sub 3}O{sub 4}@GO) to form Fe{sub 3}O{sub 4}@GO-DES for the magnetic solid-phase extraction of protein. X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) were employed to characterize Fe{sub 3}O{sub 4}@GO-DES, and the results indicated the successful preparation of Fe{sub 3}O{sub 4}@GO-DES. The UV–vis spectrophotometer was used to measure the concentration of protein after extraction. Single factor experiments proved that the extraction amount was influenced by the types of DESs, solution temperature, solution ionic strength, extraction time, protein concentration and the amount of Fe{sub 3}O{sub 4}@GO-DES. Comparison of Fe{sub 3}O{sub 4}@GO and Fe{sub 3}O{sub 4}@GO-DES was carried out by extracting bovine serum albumin, ovalbumin, bovine hemoglobin and lysozyme. The experimental results showed that the proposed Fe{sub 3}O{sub 4}@GO-DES performs better than Fe{sub 3}O{sub 4}@GO in the extraction of acidic protein. Desorption of protein was carried out by eluting the solid extractant with 0.005 mol L{sup −1} Na{sub 2}HPO{sub 4} contained 1 mol L{sup −1} NaCl. The obtained elution efficiency was about 90.9%. Attributed to the convenient magnetic separation, the solid extractant could be easily recycled.

  4. Molecularly imprinted polymer monolith containing magnetic nanoparticles for the stir-bar sorptive extraction of triazines from environmental soil samples.

    Science.gov (United States)

    Díaz-Álvarez, Myriam; Turiel, Esther; Martín-Esteban, Antonio

    2016-10-21

    In this work, novel molecularly imprinted stir-bars based upon the entrapment of modified magnetic nanoparticles within an imprinted polymer monolith is developed for stir-bar sorptive extraction (SBSE). Firstly, magnetic nanoparticles were surface modified with oleic acid followed by encapsulation inside a silica network. Then, vinyl-groups were grafted onto the particles surface for the subsequent copolymerization with the imprinting polymerization mixture using a glass vial insert as a mold. As a result, the obtained imprinted monolith presented magnetic properties allowing its use as magnetic stir-bar. Variables affecting both polymer morphology (i.e., amount of magnetic nanoparticles, polymerization time) and binding-elution conditions of target analytes (i.e., solvents, time) was carefully optimized. Optimum imprinted stir-bars were evaluated for the SBSE of triazines in soil sample extracts. Recoveries, at 16ngg-1 concentration level, ranged from 2.4 to 8.7% with relative standard deviations lower than 15% (n=3). Although low recoveries were obtained, the high selectivity provided by the new molecularly imprinted stir-bars allowed reaching detection limits below 7.5ngg-1 by liquid chromatography coupled to UV detection. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Study and comparison of polydopamine and its derived carbon decorated nanoparticles in the magnetic solid-phase extraction of estrogens.

    Science.gov (United States)

    Huang, Zhenzhen; Lee, Hian Kee

    2015-10-02

    Surface functionalization enabled by bioinspired polydopamine (PDA) is recognized as a convenient route for fabrication of multifunctional nanoparticles. In the present work, magnetic nanoparticles with polymer (Fe3O4@PDA) and carbon shell (Fe3O4@C) were prepared by self-oxidation of dopamine, and carbonization of the PDA coating. The performance of the two magnetic sorbents in the extraction and determination of four estrogens, estrone (E1), estradiol (E2), estriol (E3) and diethylstilbestrol (DES) from water samples in the form of magnetic solid-phase extraction was investigated. Orthogonal array design was utilized to facilitate the optimization of the proposed sample preparation approach. The highest extraction capabilities of the two sorbents were achieved under different experimental conditions. Fe3O4@PDA was shown to be superior to Fe3O4@C in the enrichment of estrogens, suggesting stronger interactions were established between the PDA coating and the target compounds. The extraction and desorption operations were enabled more conveniently by magnetic separation and the extracts were analyzed by high-performance liquid chromatography coupled with ultraviolet and fluorescence detection. The limits of detection achieved in the proposed method were in the range of 0.072-0.15ng/mL for E1 and DES, and 0.0017-0.0062ng/mL for E2 and E3. Good precision (>0.9995) was obtained with the linearity ranging from 0.2 to 100ng/mL, and from 0.01 to 5ng/mL. The method developed was assessed by analysis of the estrogens in tap water, drain water and bottled mineral water samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Electromagnetic studies of nucleon and nuclear structure

    Energy Technology Data Exchange (ETDEWEB)

    Heisenberg, J.H.; Calarco, J.R.; Hersman, F.W.; Dawson, J.F.

    1993-06-01

    Important objectives of the group are the study of subatomic structure through experimental measurements and the interpretation of the data through modeling. The common theme that unifies the studies of strong interactions and hadronic systems is the effort to determine the electromagnetic response as completely as possible. The general approach is coincidence detection of exclusive final states and determination of the dependence on the spin variables using polarized beams and targets and outgoing nucleon polarimetry. Direct reaction and giant resonance studies of electron quasi-elastic scattering on {sup 12}C and {sup 16}O are reported, as well as work on nuclear structure models and instrumentation development.

  7. Experimental study of the nucleon spin structure

    Energy Technology Data Exchange (ETDEWEB)

    Litmaath, M.F.

    1996-05-07

    After introducing the theoretical framework, which includes DIS, the Quark Parton Model (QPM) and QCD, we describe the implementation of the experiment. The SMC uses a beam of 190 GeV naturally polarized muons, scattering off nucleons in a large cryogenic target containing protons or deuterons that are polarized through Dynamic Nuclear Polarization (DNP). The target material is located in two cells in a row, with opposite polarizations. Every 5 hours the polarizations of both cells are reversed. The target polarization is measured by an NMR system. The polarization of the beam is measured in a polarimeter, located downstream of the main experimental setup. (orig.).

  8. Nucleon form factors from 5D skyrmions

    Energy Technology Data Exchange (ETDEWEB)

    Panico, Giuliano [Bethe Center for Theoretical Physics and Physikalisches Institut der Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany); Wulzer, Andrea [Institut de Theorie des Phenomenes Physiques, EPFL, CH-1015 Lausanne (Switzerland)], E-mail: andrea.wulzer@epfl.ch

    2009-06-15

    Several aspects of hadron physics are well described by a simple 5D effective field theory. Baryons arise in this scenario as 'large' (and therefore calculable) 5D skyrmions. We extend and refine the existing analysis of this 5D soliton, which is fairly non-trivial due to the need of numerical methods. We perform the complete quantization of those collective coordinates which are relevant for computing the static observables like the nucleon form factors. We compare the result with simple expectations about large-N{sub c} QCD and with the experimental data. An agreement within 30% is found.

  9. Weak η production off the nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Alam, M. Rafi; Athar, M. Sajjad [Department of Physics, Aligarh Muslim University, Aligarh-202 002 (India); Alvarez-Ruso, L.; Vacas, M. J. Vicente [Departamento de Física Teórica and Instituto de Física Corpuscular, Centro Mixto Universidad de Valencia-CSIC, E-46071 Valencia (Spain)

    2015-05-15

    The weak η-meson production off the nucleon induced by (anti)neutrinos is studied at low and intermediate energies, the range of interest for several ongoing and future neutrino experiments. We consider Born diagrams and the excitation of N{sup *} (1535)S{sub 11} and N{sup *} (1650)S{sub 11} resonances. The vector part of the N-S{sub 11} transition form factors has been obtained from the MAID helicity amplitudes while the poorly known axial part is constrained with the help of the partial conservation of the axial current (PCAC) and assuming the pion-pole dominance of the pseudoscalar form factor.

  10. Effect of sintering temperature and vinca petals extract on structural and magnetic properties of delafossite CuFeO2

    Science.gov (United States)

    Dhruv, Preksha N.; Solanki, Neha; Kulkarni, Shailja; Jotania, R. B.

    2016-05-01

    Delafossite CuFeO2 multiferroic powder was synthesized using Sol-Gel auto combustion method. Influence of vinca flower petals extract on structural and magnetic property of CuFeO2 were investigated. X-ray analysis of normal samples (synthesized without presence of vinca petals extract) shows formation of hematite and ferrite phases while the sample synthesized in presence of vinca petals extract show only mono phase. The absorption bands in FTIR spectra present between 510-460 cm-1 in both the samples are due to stretching of Fe-O vibrations. VSM analysis shows that the squareness ratio (Mr/Ms) of the sample prepared using vinca petals extract obtains value of squareness ratio < 0.5, which attributes multi domain formation of samples.

  11. A higher-dimensional model of the nucleon-nucleon central potential

    Science.gov (United States)

    Hedin, Eric R.

    2014-04-01

    Based on a theory of extra dimensional confinement of quantum particles [E. R. Hedin, Physics Essays, 2012, 25(2): 177], a simple model of a nucleon-nucleon (NN) central potential is derived which quantitatively reproduces the radial profile of other models, without adjusting any free parameters. It is postulated that a higher-dimensional simple harmonic oscillator confining potential localizes particles into three-dimensional (3D) space, but allows for an evanescent penetration of the particles into two higher spatial dimensions. Producing an effect identical with the relativistic quantum phenomenon of zitterbewegung, the higher-dimensional oscillations of amplitude ħ/( mc) can be alternatively viewed as a localized curvature of 3D space back and forth into the higher dimensions. The overall spatial curvature is proportional to the particle's extra-dimensional ground state wave function in the higher-dimensional harmonic confining potential well. Minimizing the overlapping curvature (proportional to the energy) of two particles in proximity to each other, subject to the constraint that for the two particles to occupy the same spatial location one of them must be excited into the 1 st excited state of the harmonic potential well, gives the desired NN potential. Specifying only the nucleon masses, the resulting potential well and repulsive core reproduces the radial profile of several published NN central potential models. In addition, the predicted height of the repulsive core, when used to estimate the maximum neutron star mass, matches well with the best estimates from relativistic theory incorporating standard nuclear matter equations of state. Nucleon spin, Coulomb interactions, and internal nucleon structure are not considered in the theory as presented in this article.

  12. Contribution of boundness and motion of nucleons to the EMC effect

    OpenAIRE

    Birbrair, B. L.; Ryskin, M.G; Ryazanov, V. I.

    2004-01-01

    The kinematical corrections to the structure function of nucleon in nucleus due to the boundness and motion of nucleons arise from the excitation of the doorway states for one-nucleon transfer reactions in the deep inelastic scattering on nuclei.

  13. Polydopamine-coated magnetic molecularly imprinted polymer for the selective solid-phase extraction of cinnamic acid, ferulic acid and caffeic acid from radix scrophulariae sample.

    Science.gov (United States)

    Yin, Yuli; Yan, Liang; Zhang, Zhaohui; Wang, Jing; Luo, Ningjing

    2016-04-01

    We describe novel cinnamic acid polydopamine-coated magnetic imprinted polymers for the simultaneous selective extraction of cinnamic acid, ferulic acid and caffeic acid from radix scrophulariae sample. The novel magnetic imprinted polymers were synthesized by surface imprinting polymerization using magnetic multi-walled carbon nanotubes as the support material, cinnamic acid as the template and dopamine as the functional monomer. The magnetic imprinted polymers were characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy and vibrating sample magnetometry. The results revealed that the magnetic imprinted polymers had outstanding magnetic properties, high adsorption capacity, selectivity and fast kinetic binding toward cinnamic acid, ferulic acid and caffeic acid. Coupled with high-performance liquid chromatography, the extraction conditions of the magnetic imprinted polymers as a magnetic solid-phase extraction sorbent were investigated in detail. The proposed imprinted magnetic solid phase extraction procedure has been used for the purification and enrichment of cinnamic acid, ferulic acid and caffeic acid successfully from radix scrophulariae extraction sample with recoveries of 92.4-115.0% for cinnamic acid, 89.4-103.0% for ferulic acid and 86.6-96.0% for caffeic acid. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Bio-inspired green synthesis of Fe3O4 spherical magnetic nanoparticles using Syzygium cumini seed extract

    Science.gov (United States)

    Venkateswarlu, Sada; Natesh Kumar, B.; Prasad, C. H.; Venkateswarlu, P.; Jyothi, N. V. V.

    2014-09-01

    A novel and bio-inspired Fe3O4 spherical magnetic nanoparticles (SMNPs) were synthesized using Syzygium cumini (S. cumini) seed extract, which is a non-toxic ecofriendly fruit waste material. S. cumini seed extract acts as a green solvent, reducing and capping agent in which sodium acetate acts as electrostatic stabilizing agent. The green synthesized nanoparticles were characterized with the help of various techniques such as X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), Energy-dispersive spectroscopy (EDS), Vibrating sample magnetometer (VSM), FTIR spectroscopy and nitrogen adsorption and desorption analysis techniques. The XRD study divulged that the synthesized SMNPs have inverse spinel cubic structure. The hysteresis loop of Fe3O4 nanoparticles shows an excellent ferromagnetic behavior with saturation magnetization value of 13.6 emu/g.

  15. Nucleon self-energy in the relativistic Brueckner theory

    Energy Technology Data Exchange (ETDEWEB)

    Waindzoch, T.; Fuchs, C.; Faessler, A. [Inst. fuer Theoretische Physik, Univ. Tuebingen (Germany)

    1998-06-01

    The self-energy of the nucleon in nuclear matter is calculated in the relativistic Brueckner theory. We solve the Thompson equation for the two nucleon scattering in the medium using different Bonn potentials. The self-energy has a rather strong momentum dependence while the equation of state compares well with previous calculations. (orig.)

  16. Three-nucleon force studies at intermediate energies

    NARCIS (Netherlands)

    Messchendorp, JG; KalantarNayestanaki, N; Timmermans, RGE; Bakker, BLG

    2005-01-01

    High-precision data in three-nucleon scattering processes and state-of-the-art few-body calculations have contributed significantly to our present understanding of three-nucleon forces at intermediate energies. This paper discusses in more detail the pd -> He-3 gamma reaction as a probe for

  17. Nucleon form factors program with SBS at JLAB

    Energy Technology Data Exchange (ETDEWEB)

    Wojtsekhowski, Bogdan B. [JLAB

    2014-12-01

    The physics of the nucleon form factors is the basic part of the Jefferson Laboratory program. We review the achievements of the 6-GeV era and the program with the 12- GeV beam with the SBS spectrometer in Hall A, with a focus on the nucleon ground state properties.

  18. Nucleon resonance decay by the $ K^{0}\\sum^{+} $ channel ...

    Indian Academy of Sciences (India)

    The strange meson production on a proton target in the K 0 ∑ + channel is sensitive to nucleon resonance contributions. The K 0 production on a deuteron target can provide information on the hyperon-nucleon final-state interaction. The experiments p → K 0 ∑ + and d → K 0 ∑ + n have been carried out at the ELSA ...

  19. Facile synthesis of magnetic carbon nitride nanosheets and its application in magnetic solid phase extraction for polycyclic aromatic hydrocarbons in edible oil samples.

    Science.gov (United States)

    Zheng, Hao-Bo; Ding, Jun; Zheng, Shu-Jian; Zhu, Gang-Tian; Yuan, Bi-Feng; Feng, Yu-Qi

    2016-01-01

    In this study, we proposed a method to fabricate magnetic carbon nitride (CN) nanosheets by simple physical blending. Low-cost CN nanosheets prepared by urea possessed a highly π-conjugated structure; therefore the obtained composites were employed as magnetic solid-phase extraction (MSPE) sorbent for extraction of polycyclic aromatic hydrocarbons (PAHs) in edible oil samples. Moreover, sample pre-treatment time could be carried out within 10 min. Thus, a simple and cheap method for the analysis of PAHs in edible oil samples was established by coupling magnetic CN nanosheets-based MSPE with gas chromatography-mass spectrometry (GC/MS) analysis. Limits of quantitation (LOQs) for eight PAHs ranged from 0.4 to 0.9 ng/g. The intra- and inter-day relative standard deviations (RSDs) were less than 15.0%. The recoveries of PAHs for spiked soybean oil samples ranged from 91.0% to 124.1%, with RSDs of less than 10.2%. Taken together, the proposed method offers a simple and cost-effective option for the convenient analysis of PAHs in oil samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Nucleon electric dipole moments in high-scale supersymmetric models

    Energy Technology Data Exchange (ETDEWEB)

    Hisano, Junji [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI),Nagoya University,Nagoya 464-8602 (Japan); Department of Physics, Nagoya University,Nagoya 464-8602 (Japan); Kavli IPMU (WPI), UTIAS, University of Tokyo,Kashiwa, Chiba 277-8584 (Japan); Kobayashi, Daiki; Kuramoto, Wataru; Kuwahara, Takumi [Department of Physics, Nagoya University,Nagoya 464-8602 (Japan)

    2015-11-12

    The electric dipole moments (EDMs) of electron and nucleons are promising probes of the new physics. In generic high-scale supersymmetric (SUSY) scenarios such as models based on mixture of the anomaly and gauge mediations, gluino has an additional contribution to the nucleon EDMs. In this paper, we studied the effect of the CP-violating gluon Weinberg operator induced by the gluino chromoelectric dipole moment in the high-scale SUSY scenarios, and we evaluated the nucleon and electron EDMs in the scenarios. We found that in the generic high-scale SUSY models, the nucleon EDMs may receive the sizable contribution from the Weinberg operator. Thus, it is important to compare the nucleon EDMs with the electron one in order to discriminate among the high-scale SUSY models.

  1. Magnetic graphene solid-phase extraction for the determination of carbamate pesticides in tomatoes coupled with high performance liquid chromatography.

    Science.gov (United States)

    Li, Na; Chen, Juan; Shi, Yan-Ping

    2015-08-15

    Graphene-based magnetic nanoparticles, comprising zero-valent iron, iron oxide-oxyhydroxide and graphene, were prepared through a simple one-step synthesis method, and subsequently applied to magnetic solid-phase extraction for the determination of trace carbamate pesticides in tomatoes coupled with high performance liquid chromatography. The properties of the nanocomposites were confirmed by using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and vibrating sample magnetometer. The components within the nanocomposites endowed the material with high extraction performance and manipulative convenience. Compared with reduced graphene oxide, the as-prepared G-MNPs showed the better extraction efficiencies for the carbamate pesticides thanks to the contribution of the iron-containing magnetic nanoparticles to the adsorption capacity of the nanocomposites. Various experimental parameters affecting the extraction efficiency had been investigated in detail. Under the optimal conditions, the method provided high enrichment factors ranging from 364 to 434, good linearities ranging from 5 to 200ng g(-1) for metolcarb, baygon and methiocarb and 10 to 200ng g(-1) for carbofuran and isoprocarb, low limits of detection ranging from 0.58 to 2.06ng g(-1), and satisfactory spiked recoveries (between 90.34% and 101.98% with the relative standard deviation values from 1.21% to 5.93%). It was confirmed that this novel method was an efficient pretreatment and enrichment procedure and could be successfully applied for extraction and determination of trace carbamate pesticides in complex matrices. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Rapid magnetic solid-phase extraction based on monodisperse magnetic single-crystal ferrite nanoparticles for the determination of free fatty acid content in edible oils.

    Science.gov (United States)

    Wei, Fang; Zhao, Qin; Lv, Xin; Dong, Xu-Yan; Feng, Yu-Qi; Chen, Hong

    2013-01-09

    This study proposes a rapid magnetic solid-phase extraction (MSPE) based on monodisperse magnetic single-crystal ferrite (Fe(3)O(4)) nanoparticles (NPs) for determining the quantities of eight free fatty acids (FFAs), including palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2), linolenic acid (C18:3), arachidic acid (C20:0), eicosenoic acid (C20:1), and behenic acid (C22:0) in oil. The amine-functionalized mesoporous Fe(3)O(4) magnetic NPs were applied as a sorbent for MSPE of FFAs from oil samples in a process that is based on hydrophilic interaction. The extraction can be completed rapidly in a dispersive mode with the aid of vigorous vortex. Additional tedious processing steps such as centrifugation and evaporation of organic solvent were not necessary with this procedure. Furthermore, esterification of FFAs can be accomplished during the desorption procedure by using methanol/sulfuric acid (99:1, v/v) as the desorption solvent. Several parameters affecting the extraction efficiency were investigated, including the matrix solvent for extraction, the desorption solvent and desorption time, and the amount of sorbent and extraction time. The pretreatment process was rapid under optimal conditions, being accomplished within 15 min. When coupled with gas chromatography-flame ionization detection (GC-FID), a rapid, simple, and convenient MSPE-GC-FID method for the determination of FFAs in oil samples was established with a total analysis time within 25 min. The limits of detection for the target FFAs were found to be 7.22-26.26 ng/mL. Recoveries in oil samples were in the range of 81.33-117.75%, with RSDs of <6.4% (intraday) and <6.9% (interday). This method was applied successfully to the analysis of dynamic FFA formation in four types of edible oils subjected to an accelerated storage test. The simple, rapid, and cost-effective method developed in the current study offers a potential application for the extraction and

  3. Magnetic graphene dispersive solid phase extraction combining high performance liquid chromatography for determination of fluoroquinolones in foods.

    Science.gov (United States)

    He, Xin; Wang, Geng Nan; Yang, Kun; Liu, Hui Zhi; Wu, Xia Jun; Wang, Jian Ping

    2017-04-15

    In this study, a magnetic graphene-based dispersive solid phase extraction method was developed that was combined with high performance liquid chromatography to determine the residues of fluoroquinolone drugs in foods of animal origin. During the experiments, several parameters possible influencing the extraction performance were optimized (amount of magnetic graphene, sample pH, extraction time and elution solution). This extraction method showed high absorption capacities (>6800ng) and high enrichment factors (68-79-fold) for seven fluoroquinolones. Furthermore, this absorbent could be reused for at least 40 times. The limits of detection were in the range of 0.05-0.3ng/g, and the recoveries from the standards fortified blank samples (bovine milk, chicken muscle and egg) were in the range of 82.4-108.5%. Therefore, this method could be used as a simple and sensitive tool to determine the residues of fluoroquinolones in foods of animal origin. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Investigation of Di-ethylhexyl Phthalate Migration by Applying Magnetic Solid Phase Extraction Method Followed by GC-FID Determination

    Directory of Open Access Journals (Sweden)

    Mohammad Faraji

    2016-10-01

    Full Text Available Background and Objectives: The addition of plasticizers (mainly phthalates and adipates makes plastic flexible and popular for packaging, storing and preserving food, water, and so on. The most widely used plasticizer in food contact applications is di-ethylhexyl phthalate (DEHP though being suspected to have carcinogenic and estrogenic properties. The aim of this study is application of magnetic solid phase extraction as new absorbent for determination of DEHP in water samples by gas chromatography (GC. Materials and Methods: Important factors in extraction, separation and determination processes were optimized using the one-variable-at-a-time method. For optimization, all tests were performed two times. Figures of merit of the proposed method were evaluated. The amount of DEHP in some water samples was determined using the proposed method. Results: The results showed that the obtained chromatogram of extract was free of significant interference. The preservatives’ recoveries ranged from 91.6% to 102.2%. Limit of detection and limit of quantitation were 0.1 mg kg-1 and 0.3 µg L-1, respectively. Concentration of DEHP in the studied samples was in the range of N.D-2.3 µg L-1. Conclusions: The acceptable performance and reliability of the proposed method were demonstrated. Temperature and time were fount as the most effective parameters in migration of DEHP. Keywords: Di-ethylhexyl phthalate, Magnetic solid phase extraction, Migration, Gas chromatography

  5. New large-Nc relations among the nucleon and nucleon-to-Delta GPDs

    Energy Technology Data Exchange (ETDEWEB)

    Marc Vanderhaeghen; Vladimir Pascalutsa

    2006-11-15

    We establish relations which express the generalized parton distributions (GPDs) describing the N {yields} {Delta} transition in terms of the nucleon GPDs. These relations are based on the known large-N{sub c} relation between the N {yields} {Delta} electric quadrupole moment and the neutron charge radius, and a newly derived large-N{sub c} relation between the electric quadrupole (E2) and Coulomb quadrupole (C2) transitions. Namely, in the large-N{sub c} limit we find C2=E2. The resulting relations among the nucleon and N {yields} {Delta} GPDs provide predictions for the N {yields} {Delta} electromagnetic form factors which are found to be in very good agreement with experiment for moderate momentum transfers.

  6. A versatile dielectron trigger for nucleon-nucleon and nucleus-nucleus collisions

    CERN Document Server

    Schicker, R; Tsertos, H

    1998-01-01

    A novel approach for a versatile first level dielectron trigger is presented. This trigger operates in the low multiplicity environment of nucleon-nucleon reactions as well as in the high multiplicity situation of nucleus-nucleus collisions. For optimal trigger performance, time of flight conditions for the two fastest particles of the event are combined with event multiplicity requirements. The dielectron trigger efficiency is given. The event reduction factor of such a trigger approach is studied for a low, a medium and a high multiplicity environment. The impact parameter dependence of the event reduction is given. The timing properties of the trigger signal are described. The losses due to deadtime are specified. Finally, the first level trigger rate is reported.

  7. Lectures from the workshop on nucleon-nucleon bremsstrahlung, January 25--26, 1990

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, B.F.; Schillaci, M.E.; Wender, S.A. (comps.)

    1990-07-01

    The Nucleon-Nucleon Bremsstrahlung Workshop was convened at LAMPF on 25--26 January 1990 in order to review the theoretical and experimental aspects of that reaction with focus on a possible new initiative to measure neutron-proton bremsstrahlung using the intermediate-energy, white-spectrum neutron source at the LAMPF/WNR facility. Over the course of this intense day-and-a-half workshop, experts in the field established the historical perspective for both theory and experiment, presented result of recent calculations, and examined new approaches to the difficult neutron-proton bremsstrahlung experiment. Theoretical and experimental working groups generated recommendations for action and actually converged upon a plan for an experimental program, not just a single measurement.

  8. Measurement of Hadron Multiplicities in Deep Inelastic Muon-Nucleon Scattering

    CERN Document Server

    du Fresne von Hohenesche, Nicolas

    2016-06-02

    In deep-inelastic muon-nucleon scattering, a single quark can be ejected out of the nucleon by the absorption of a high-energy photon. Such a free isolated quark has never been observed in nature. In quantum chromodynamics (QCD), coloured objects, such as a single quark, create additional quark anti-quark pairs out of the colour field and the final state comprises a jet of hadrons. The hadronisation process can be described by fragmentation functions D_q^h, the probability that a quark with the flavour q turns into a hadron of the type h. Similar to the parton distribution function, the fragmentation functions are fundamental, universal and process-independent quantities. The fragmentation functions are measured with the COM- PASS spectrometer in muon-nucleon scattering. The observables are the hadron multiplicities M_h. The COMPASS experiment consists of a two-stage magnetic spectrometer located at the M2 beam line of the Super Proton Synchrotron at CERN and uses a polarised muon beam on a nuclear fixed targ...

  9. Ground state characteristics of the light nuclei with A<=6 on the basis of the translation invariant shell model by using nucleon-nucleon interaction

    CERN Document Server

    Doma, S B

    2002-01-01

    Phenomenological nucleon-nucleon interaction consisting of central, tensor, spin-orbit and quadratic spin-orbit terms, with Gaussian radial dependence, are constructed by varying their parameters in order to obtain the best fit between the calculated and the experimental values of the binding energy, the root mean-square radius, the D-state probability, the magnetic dipole moment and the electric quadrupole moment of deuteron. The ground-state nuclear wave function of deuteron is expanded in terms of the translation-invariant shell model basis functions corresponding to the number of quanta of excitation 0 <= N <=10. Moreover, the binding energy, the root mean-square radius and the magnetic dipole moment of the nuclei sup 3 H, sup 4 He, sup 5 He and sup 6 Li are also calculated by using the new interactions. The wave functions of these nuclei are expanded in terms of the basis functions of the translation-invariant shell model with N = 10 for the first tow nuclei, N = 7 for sup 5 he and N = 6 for sup 6 ...

  10. Probing nucleon-nucleon correlations in heavy-ion transfer reactions

    Directory of Open Access Journals (Sweden)

    Szilner S.

    2016-01-01

    Full Text Available The γ-particle coincident measurements, performed by coupling of the PRISMA spectrometer to the large γ arrays (CLARA and AGATA, demonstrate a strong interplay between single-particle and collective degrees of freedom that is pertinent to the reaction dynamics. By using the unique PRISMA performance in terms of both resolution and efficiency, measurements at very low bombarding energies have been performed. Via transfer of nucleon pairs, valuable information on the component responsible for particle correlations has been derived.

  11. From Nucleons To Nuclei To Fusion Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Quaglioni, S; Navratil, P; Roth, R; Horiuchi, W

    2012-02-15

    Nuclei are prototypes of many-body open quantum systems. Complex aggregates of protons and neutrons that interact through forces arising from quantum chromo-dynamics, nuclei exhibit both bound and unbound states, which can be strongly coupled. In this respect, one of the major challenges for computational nuclear physics, is to provide a unified description of structural and reaction properties of nuclei that is based on the fundamental underlying physics: the constituent nucleons and the realistic interactions among them. This requires a combination of innovative theoretical approaches and high-performance computing. In this contribution, we present one of such promising techniques, the ab initio no-core shell model/resonating-group method, and discuss applications to light nuclei scattering and fusion reactions that power stars and Earth-base fusion facilities.

  12. Structure and spin of the nucleon

    Directory of Open Access Journals (Sweden)

    Avakian H.

    2014-03-01

    Great progress has been made since then in measurements of different Single Spin Asymmetries (SSAs in semi-inclusive and hard exclusive processes providing access to TMDs and GPDs, respectively. Facilities world-wide involved in studies of the 3D structure of nucleon include HERMES, COMPASS, BELLE, BaBar, Halls A, B, and C at JLab, and PHENIX and STAR at RHIC (BNL. TMD studies in the Drell-Yan process are also becoming an important part of the program of hadron scattering experiments. Studies of TMDs are also among the main driving forces of the JLab 12-GeV upgrade project, several of the forward upgrade proposals of STAR and PHENIX at RHIC, and future facilities, such as the Electron Ion Collider (EIC, FAIR in Germany, and NICA in Russia. In this contribution we present an overview of the latest developments in studies of parton distributions and discuss newly released results, ongoing activities, as well as some future measurements.

  13. Nucleon form factors with light Wilson quarks

    CERN Document Server

    Green, Jeremy; Krieg, Stefan; Meinel, Stefan; Negele, John; Pochinsky, Andrew; Syritsyn, Sergey

    2013-01-01

    We present nucleon observables - primarily isovector vector form factors - from calculations using 2+1 flavors of Wilson quarks. One ensemble is used for a dedicated high-precision study of excited-state effects using five source-sink separations between 0.7 and 1.6 fm. We also present results from a larger set of calculations that include an ensemble with pion mass 149 MeV and box size 5.6 fm, which nearly eliminates the uncertainty associated with extrapolation to the physical pion mass. The results show agreement with experiment for the vector form factors, which occurs only when excited-state contributions are reduced. Finally, we show results from a subset of ensembles that have pion mass 254 MeV with varying temporal and spatial box sizes, which we use for a controlled study of finite-volume effects and a test of the "$m_\\pi L=4$" rule of thumb.

  14. Neutrino-nucleon cross section measurements in NOMAD

    CERN Document Server

    Wu, Qun

    2006-01-01

    The NOMAD (Neutrino Oscillation MAgnetic Detector) experiment, using the SPS (Super Proton Syncrotron) neutrino beam (1 GeV < E [nu] < 200 GeV) at CERN (European Organization for Nuclear Research), has collected more than 1.7 million neutrino induced charged and neutral current (CC and NC) events. This data is the largest high resolution neutrino nucleon scattering data to date and is ideal for precision measurements and searches in neutrino-physics. This thesis presents the precise measurement of the inclusive neutrino CC cross section in 2.5 GeV < E [nu] < 150 GeV region. The linear dependence of the inclusive CC cross section ([Special characters omitted.] ) versus the incoming neutrino energy ( E [nu] ) is observed in the high energy region of 30 GeV < E [nu] < 150 GeV. Especially, the measurement in 2.5 GeV < E [nu] < 30 GeV region provides the first precise determination of [Special characters omitted.] . The significant deviation from the linear dependence for [Special character...

  15. Leading nucleons from peripheral processes in lepton deep inelastic scattering and the nucleon structure

    CERN Document Server

    Szczurek, A

    1999-01-01

    The experimental information on nucleon production in lepton deep inelastic scattering (DIS) is rather scarce. Recently there is a growing interest in understanding the mechanism of the production of baryons in DIS, stimulated by recent results on leading protons and neutrons from electron-proton scattering at HERA. I review on different peripheral mechanisms of nucleon (proton or neutron) production in lepton DIS and discuss their role in understanding the spectra of nucleons for both fixed target and collider experiments. In DIS ep to e'Xh, the QCD hardness scale gradually diminishes from the hard scale, Q/sup 2/, in the virtual photon (current) fragmentation region to the soft, hadronic, scale in the proton (target) fragmentation region. This suggests a similarity of the inclusive spectra of leading protons and neutrons, h=p, n, in high energy hadron-proton collisions and in lepton DIS at small Bjorken-x. The semi-inclusive cross section for production of slow protons in charged-current deep inelastic (ant...

  16. EXTRACT

    DEFF Research Database (Denmark)

    Pafilis, Evangelos; Buttigieg, Pier Luigi; Ferrell, Barbra

    2016-01-01

    The microbial and molecular ecology research communities have made substantial progress on developing standards for annotating samples with environment metadata. However, sample manual annotation is a highly labor intensive process and requires familiarity with the terminologies used. We have the...... and text-mining-assisted curation revealed that EXTRACT speeds up annotation by 15-25% and helps curators to detect terms that would otherwise have been missed.Database URL: https://extract.hcmr.gr/......., organism, tissue and disease terms. The evaluators in the BioCreative V Interactive Annotation Task found the system to be intuitive, useful, well documented and sufficiently accurate to be helpful in spotting relevant text passages and extracting organism and environment terms. Comparison of fully manual...

  17. The spin structure of the nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Le Goff, J.M

    2005-02-15

    The nucleon is a spin 1/2 particle. This spin can be decomposed into the contributions of its constituents: 1/2 equals 1/2*{delta}{sigma} + {delta}g + L{sub q} + L{sub g} where the first term is the contribution from the spin of the quarks, the second term is the contribution from the spin of the gluons and L{sub q} and L{sub g} are the orbital momentum of the quark and the gluon respectively. The {delta}{sigma} contribution of the spin of quarks can be studied through polarized deep inelastic scattering (DIS). We introduce DIS and the so-called parton model and then turn to the case of polarized DIS in the inclusive and semi-inclusive cases. We also discuss how a third parton distribution, called transversity, appears together with the unpolarized and the longitudinally polarized (or helicity) ones. We show how the longitudinally polarized gluon distribution can be measured. Then we focus on the SMC and COMPASS experiments performed at CERN. SMC confirmed a previous result by showing that the contribution of the spin of the quark to the spin of the nucleon was small. SMC also performed a measurement on the deuterium in order to test, for the first time, the Bjorker sum rules, which is a fundamental prediction of quantum chromodynamics. The COMPASS experiment started collecting data in 2002. Its main objectives are the gluon polarization {delta}g/g and the so-called transversity. (A.C.)

  18. Selective extraction of morphine from biological fluids by magnetic molecularly imprinted polymers and determination using UHPLC with diode array detection.

    Science.gov (United States)

    Ebrahimi Rahmani, Mahdiyeh; Ansari, Mehdi; Kazemipour, Maryam; Nateghi, Mohammadreza

    2017-11-27

    The determination of morphine concentration in the blood and urine is necessary for patients and recruitment purposes. Herein, a magnetic molecularly imprinted polymer for selective and efficient extraction of morphine from biological samples was synthesized by using a core-shell method. Fe3 O4 nanoparticles were coated with SiO2 -NH2 . The molecularly imprinted polymer was coated on the Fe3 O4 /SiO2 -NH2 surface by the copolymerization of methacrylic acid and ethylene glycol dimethacrylate in the presence of morphine as the template molecule. The morphological and magnetic properties of the polymer were investigated. Field-emission scanning electron microscopy indicated that the prepared magnetic polymer is almost uniform. The saturation magnetization values of Fe3 O4 nanoparticles, Fe3 O4 /SiO2 -NH2 , and the magnetic polymer were 48.41, 31.69, and 13.02 emu/g, respectively, indicating that all the particles are superparamagnetic. Kinetics of the adsorption of morphine on magnetic polymer were well described by second-order kinetic and adsorption processes and well fitted by the Langmuir adsorption isotherm, in which the maximum adsorption capacity was calculated as 28.40 mg/g. The recoveries from plasma and urine samples were in the range of 84.9-105.5 and 94.9-102.8%, respectively. By using the magnetic molecularly imprinted polymer, morphine can selectively, reliably, and in low concentration be determined in biological samples with high-performance liquid chromatography and UV detection. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Synthesis of multirecognition magnetic molecularly imprinted polymer by atom transfer radical polymerization and its application in magnetic solid-phase extraction.

    Science.gov (United States)

    Kong, Xiang-Jin; Zheng, Chao; Lan, Yao-Han; Chi, Shuai-Shuai; Dong, Qian; Liu, Hao-Long; Peng, Chao; Dong, Lin-Yi; Xu, Liang; Wang, Xian-Hua

    2018-01-01

    In this work, we reported an effective method for the synthesis of a multirecognition magnetic molecularly imprinted polymer (MMIP) with atom transfer radical polymerization (ATRP), using 2,4-diamino-6-methyl-1,3,5-triazine as pseudo-template. The resulting MMIP was characterized in detail by Fourier transform-infrared (FT-IR) spectra, scanning electron microscopy (SEM), thermogravimetic analysis (TGA), and vibrating sample magnetometry (VSM). These results indicated the successful synthesis of MMIP with sufficient thermal stability and magnetic properties. The adsorption experiments were carried out to evaluate the specific selectivity of MMIP related to the spatial structure of target molecules. The MMIP exhibited multirecognition ability and excellent binding capability for melamine (MEL), cyromazine (CYR), triamterene (TAT), diaveridine (DVD), and trimethoprim (TME), and the apparent maximum number of binding sites (Q max) was 77.5, 75.2, 72.5, 69.9, and 70.4 μmol g-1, respectively. The multirecognition MMIP not only possessed adequate magnetic responsiveness for fast separation but also avoided the risk of template leakage on trace component analysis. Therefore, it was suitable for serving as a magnetic solid-phase extraction (MSPE) adsorbent. MSPE coupled with high-performance liquid chromatography analysis was applied to enrich and separate five target molecules from three samples. Recoveries for all target molecules ranged from 81.6 to 91.5% with relative standard deviations of no more than 4.1% (n = 3). Graphical abstract Multirecognition property of magnetic molecularly imprinted polymer prepared with pseudo template.

  20. Cytotoxic effect of magnetic iron oxide nanoparticles synthesized via seaweed aqueous extract

    Science.gov (United States)

    Namvar, Farideh; Rahman, Heshu Sulaiman; Mohamad, Rosfarizan; Baharara, Javad; Mahdavi, Mahnaz; Amini, Elaheh; Chartrand, Max Stanley; Yeap, Swee Keong

    2014-01-01

    Magnetic iron oxide nanoparticles (Fe3O4 MNPs) are among the most useful metal nanoparticles for multiple applications across a broad spectrum in the biomedical field, including the diagnosis and treatment of cancer. In previous work, we synthesized and characterized Fe3O4 MNPs using a simple, rapid, safe, efficient, one-step green method involving reduction of ferric chloride solution using brown seaweed (Sargassum muticum) aqueous extract containing hydroxyl, carboxyl, and amino functional groups mainly relevant to polysaccharides, which acts as a potential stabilizer and metal reductant agent. The aim of this study was to evaluate the in vitro cytotoxic activity and cellular effects of these Fe3O4 MNPs. Their in vitro anticancer activity was demonstrated in human cell lines for leukemia (Jurkat cells), breast cancer (MCF-7 cells), cervical cancer (HeLa cells), and liver cancer (HepG2 cells). The cancer cells were treated with different concentrations of Fe3O4 MNPs, and an MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay was used to test for cytotoxicity, resulting in an inhibitory concentration 50 (IC50) value of 23.83±1.1 μg/mL (HepG2), 18.75±2.1 μg/mL (MCF-7), 12.5±1.7 μg/mL (HeLa), and 6.4±2.3 μg/mL (Jurkat) 72 hours after treatment. Therefore, Jurkat cells were selected for further investigation. The representative dot plots from flow cytometric analysis of apoptosis showed that the percentages of cells in early apoptosis and late apoptosis were increased. Cell cycle analysis showed a significant increase in accumulation of Fe3O4 MNP-treated cells at sub-G1 phase, confirming induction of apoptosis by Fe3O4 MNPs. The Fe3O4 MNPs also activated caspase-3 and caspase-9 in a time-response fashion. The nature of the biosynthesis and therapeutic potential of Fe3O4 MNPs could pave the way for further research on the green synthesis of therapeutic agents, particularly in nanomedicine, to assist in the treatment of cancer. PMID

  1. General aspects of the nucleon-nucleon interaction and nuclear matter properties

    Energy Technology Data Exchange (ETDEWEB)

    Plohl, Oliver

    2008-07-25

    The subject of the present thesis is at first the investigation of model independent properties of the nucleon-nucleon (NN) interaction in the vacuum concerning the relativistic structure and the implications for nuclear matter properties. Relativistic and non-relativistic meson-exchange potentials, phenomenological potentials s well as potentials based on effective field theory (EFT) are therefore mapped on a relativistic operator basis given by the Clifford Algebra. This allows to compare the various approaches at the level of covariant amplitudes where a remarkable agreement is found. Furthermore, the relativistic self-energy is determined in the Hartree-Fock (HF) approximation. The appearance of a scalar and vector field of several hundred MeV magnitude is a general feature of relativistic descriptions of nuclear matter. Within QCD sum rules these fields arise due to the density dependence of chiral condensates. We find that independent of the applied NN interaction large scalar and vector fields are generated when the symmetries of the Lorentz group are restored. In the framework of chiral EFT (chEFT) it is shown, that these fields are generated by short-range next-to-leading order (NLO) contact terms, which are connected to the spin-orbit interaction. To estimate the effect arising from NN correlations the equation of state of nuclear and neutron matter is calculated in the Brueckner-HF (BHF) approximation applying chEFT. Although, as expected, a clear over-binding is found (at NLO a saturating behavior is observed), the symmetry energy shows realistic properties when compared to phenomenological potentials (within the same approximation) and other approaches. The investigation of the pion mass dependence within chEFT at NLO shows that the magnitude of the scalar and vector fields persists in the chiral limit - nuclear matter is still bound. In contrast to the case of a pion mass larger than the physical one the binding energy and saturation density are

  2. Strange content of the nucleon: asymmetry measurement of parity violation in the PVA4 experiment at MAMI (Mainzer Mikrotron); Contenu etrange du nucleon: mesure de l'asymetrie de violation de parite dans l'experience PVA4 a MAMI. Etude et developpement d'un polarimetre optique

    Energy Technology Data Exchange (ETDEWEB)

    Blaise, C

    2002-11-01

    Nucleons are bound states of three valence quarks (up and down quarks) surrounded by a sea of gluons and quark pairs (mainly up, down and strange quarks). The PVA4 experiment (Parity Violation in hall A4) aims at determining at MAMI (Mainzer Mikrotron) the contribution of the ss pairs to the electric charge and magnetic moment of the nucleon. This requires the extraction of information from the weak coupling in the elastic scattering of polarized electrons off target protons. The parity non-conserving Z{sup 0} exchange leads to a parity violating asymmetry in the count rates for left and right helicity states. Comparison of the measured asymmetry to the predictions of the Standard Model allows then to extract the strange content of the proton. The success of the experiment essentially lies in the ability of controlling the beam parameters and evaluating the physical background. For this purpose, a Monte Carlo simulation has been developed: it simulates the PVA4 electron-proton scattering (including geometry and detection) for different processes (elastic scattering and pion electroproduction) thus allowing to correct the experimental asymmetry from physical background processes. In addition, an optical polarimeter has been developed to get a precise, on-line and fast measurement of the electron beam polarization. The optical polarimeter (POLO) is based on the collision of polarized electrons on atoms such that spin angular momentum is transferred to the excited atoms, which subsequently decays by emitting a circularly polarized fluorescence. The degree of circular polarization is directly related to the electron polarization. Analyzing the fluorescence's Stokes parameters is equivalent to a measurement of the electron beam polarization. (author)

  3. Development of a magnetic coagulant based on Moringa oleifera seed extract for water treatment.

    Science.gov (United States)

    Santos, Tássia R T; Silva, Marcela F; Nishi, Leticia; Vieira, Angélica M S; Fagundes-Klen, Márcia R; Andrade, Murilo B; Vieira, Marcelo F; Bergamasco, Rosângela

    2016-04-01

    In this work, to evaluate the effectiveness of the coagulation/flocculation using a natural coagulant, using Moringa oleifera Lam functionalized with magnetic iron oxide nanoparticles, producing flakes that are attracted by an external magnetic field, thereby allowing a fast settling and separation of the clarified liquid, is proposed. The removal efficiency of the parameters, apparent color, turbidity, and compounds with UV254nm absorption, was evaluated. The magnetic functionalized M. oleifera Lam coagulant could effectively remove 90 % of turbidity, 85 % of apparent color, and 50 % for the compounds with absorption at UV254nm, in surface waters under the influence of an external magnetic field within 30 min. It was found that the coagulation/flocculation treatment using magnetic functionalized M. oleifera Lam coagulant was able to reduce the values of the physico-chemical parameters evaluated with reduced settling time.

  4. Magnetic nanoporous carbon as an adsorbent for the extraction of phthalate esters in environmental water and aloe juice samples.

    Science.gov (United States)

    Liu, Li; Hao, Yunhui; Ren, Yiqian; Wang, Chun; Wu, Qiuhua; Wang, Zhi

    2015-05-01

    In this work, magnetic nanoporous carbon with high surface area and ordered structure was synthesized using cheap commercial silica gel as template and sucrose as the carbon source. The prepared magnetic nanoporous carbon was firstly used as an adsorbent for the extraction of phthalate esters, including diethyl phthalate, diallyl phthalate, and di-n-propyl-phthalate, from lake water and aloe juice samples. Several parameters that could affect the extraction efficiency were optimized. Under the optimum conditions, the limit of detection of the method (S/N = 3) was 0.10 ng/mL for water sample and 0.20 ng/mL for aloe juice sample. The linearity was observed over the concentration range of 0.50-150.0 and 1.0-200.0 ng/mL for water and aloe juice samples, respectively. The results showed that the magnetic nanoporous carbon has a high adsorptive capability toward the target phthalate esters in water and aloe juice samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Extraction of methylmercury and ethylmercury from aqueous solution using surface sulfhydryl-functionalized magnetic mesoporous silica nanoparticles.

    Science.gov (United States)

    Li, Guangzhu; Liu, Miao; Zhang, Zhuqing; Geng, Chao; Wu, Zhongbo; Zhao, Xin

    2014-06-15

    Surface sulfhydryl-functionalized magnetic mesoporous silica nanoparticles were prepared, aiming to extract trace alkylmercury from aqueous solution. The prepared nanoparticles were characterized by TEM, ED, EDX, DLS, FTIR, and SERS. Compare with that the non-sulfhydryl-functionalized Fe3O4@SiO2 exhibited almost no affinity for CH3Hg(+) and CH3CH2Hg(+); the sulfhydryl-functionalized Fe3O4@SiO2 exhibited high adsorption affinity for them, resulting from chelating interaction by surface sulfhydryl group, and the adsorption was not significantly impacted by pH within the range of 3.5-9.0 or coexisting metal ions. The monolayer adsorption on surface of Fe3O4@SiO2-RSH could reach equilibrium in 2 min. Moreover, the CH3Hg(+) and CH3CH2Hg(+) adsorbed on Fe3O4@SiO2-RSH could be quickly separated from the matrix in a magnetic field and desorbed easily by acetonitrile and l-cysteine aqueous solution or HCl solution, and the recoveries were more than 80%. Findings of the present work highlight the potential for using Fe3O4@SiO2-RSH magnetic nanoparticles as effective and reusable adsorbents for extraction of ultra trace alkylmercury from environmental water samples. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Elastic and inelastic pion reactions on few nucleon systems

    Energy Technology Data Exchange (ETDEWEB)

    Lensky, V.

    2007-09-29

    In the present work, we are studying elastic and inelastic pion reactions on few-body systems within the framework of chiral effective theory. We consider two specific reactions involving pions on few-nucleon systems, namely pion production in nucleon-nucleon collisions, and incoherent pion photoproduction on the deuteron. These two reactions are closely related to the issue of dispersive and absorptive corrections to the pion-deuteron scattering length, which we also consider in our analysis. The incoherent pion photoproduction is also considered as the possible source for a high-precision determination of the neutron-neutron scattering length. (orig.)

  7. Perturbative Pions in Effective Field Theory for Nucleon Interactions

    Science.gov (United States)

    Mehen, Thomas

    2001-12-01

    I discuss pions in effective field theory (EFT) for the nucleon interaction within the power counting scheme proposed by Kaplan-Savage-Wise (KSW). After explaining why KSW power counting demands perturbative treatment of pions, I present results of next-to-next-to-leading order (NNLO) calculations of nucleon-nucleon scattering in S-,P-, and D-wave channels. Perturbative treatment of pions fails in spin-triplet channels. The origin of large perturbative corrections is the piece of the spin-tensor force which survives in the chiral limit.

  8. Two Nucleon (B-L)-Conserving Reactions Involving Tau Leptons

    OpenAIRE

    Bryman, Douglas

    2014-01-01

    Tau lepton emission in two-nucleon disappearance reactions from within nuclei which conserve baryon number minus lepton number (B − L) is considered. It is shown that some existing limits on proton decay channels and two-nucleon disappearance reactions resulting in electrons and muons can be applied to ΔB=ΔL=2 decays involving τ leptons. For the two-nucleon disappearance channel np→τ+ν¯τ the estimated limit for the partial mean life is τBr>1×1030 yrs based on results from the IMB3 experime...

  9. Polydopamine-reinforced magnetization of zeolitic imidazolate framework ZIF-7 for magnetic solid-phase extraction of polycyclic aromatic hydrocarbons from the air-water environment.

    Science.gov (United States)

    Zhang, Suling; Yao, Weixuan; Ying, Jianbo; Zhao, Hongting

    2016-06-24

    Zeolitic imidazolate frameworks (ZIFs) consist of metal nodes connected to imidazolate linkers, having both the properties of metal-organic frameworks (MOFs) and inorganic zeolites, such as controllable pore sizes, high porosity and surface areas, as well as exceptional thermal and chemical stability, thereby making them a class of attractive materials for diverse analytical applications. In this study, we reported a facile magnetization process of ZIF-7 (zinc benzimidazolate) for simultaneous magnetic extraction of polycyclic aromatic hydrocarbons (PAHs) by simply mixing ZIF-7 and polydopamine (PDA)-coated Fe3O4 nanoparticles (PDA@Fe3O4) in solutions. Functional groups (-OH and -NH2), provided by PDA as a highly efficient molecular linker, could attract and anchor ZIF-7 through noncovalent adsorption and covalent cross-link interactions, thereby promoting the complete magnetization of ZIFs and enhancing their stability and reusability. The bridging ligand benzimidazolate, could be bonded with PAHs because of its high surface area, large pores, accessible coordinative unsaturated sites (π-complexation), and π-π stacking action. This ZIF-based magnetic solid-phase extraction (SPE), coupled with gas chromatography/tandem mass spectrometry (GC/MS), was further evaluated for analysis of PAHs from rainwater and air samples of particulate matter less than 2.5μm in diameter (PM2.5). The main effective parameters, including ionic strength, solution pH, extraction time, desorption solvent and desorption time, were investigated, respectively. Under optimized conditions, the developed method based on Fe3O4@PDA/ZIF-7 gave detection limits of 0.71-5.79ng/L, and quantification limits of 2.50-19.2ng/L for PAHs, respectively. The relative standard deviations for intra-day and inter-day analyses were in the range of 3.1-9.1% and 6.1-12.7%, respectively. The PAHs founded in PM2.5 were in the range of 0.40-6.79ng/m(3). Good recoveries (>82%) with low relative standard deviations

  10. Biogenic synthesis of Fe3O4 magnetic nanoparticles using Pisum sativum peels extract and its effect on magnetic and Methyl orange dye degradation studies

    Science.gov (United States)

    Prasad, Cheera; Yuvaraja, Gutha; Venkateswarlu, Ponneri

    2017-02-01

    We have been developed facile and ecofriendly method for the synthesis of Fe3O4 magnetic nanoparticles (MNPs) using an aqueous extract of Pisum sativum peels (PS) is used as reducing and capping agent. The as synthesized PS-Fe3O4 MNPs are characterized by diverse techniques such as FTIR, powder XRD, TEM, BET and Raman spectroscopy measurements. The results show that the obtained Fe3O4 nanoparticles exhibits high specific surface area (∼17.6 m2/g) and agglomerated spherical in shape with the size range of 20-30 nm. The magnetic properties of PS-Fe3O4 MNPs sample clearly exhibits ferromagnetic nature with a saturation magnetization of 64.2 emu/g. Further, the catalytic properties of PS-Fe3O4 MNPs for degradation of Methyl orange (MO) dye in aqueous solution have been investigated by UV-visible spectroscopy. The results show that PS-Fe3O4 MNPs is an efficient catalyst for degradation of Methyl orange dye than previously reported ones.

  11. Influence of transversal magnetic field on negative ion extraction process in 3D computer simulation of the multi-aperture ion source

    Science.gov (United States)

    Turek, M.; Sielanko, J.; Franzen, P.; Speth, E.

    2006-01-01

    The negative ion beam extraction from the multi-hole ion source is considered. Results of numerical simulations (based on PIC method) of the influence of transversal magnetic field aplied near the extraction grid (filter field), and in the plasma chamber volume (confining field) are presented. The application of confinig field results in significantly increased negative ions yield.

  12. Aloe vera plant-extracted solution hydrothermal synthesis and magnetic properties of magnetite (Fe3O4) nanoparticles

    Science.gov (United States)

    Phumying, Santi; Labuayai, Sarawuth; Thomas, Chunpen; Amornkitbamrung, Vittaya; Swatsitang, Ekaphan; Maensiri, Santi

    2013-06-01

    Magnetite (Fe3O4) nanoparticles have been successfully synthesized by a novel hydrothermal method using ferric acetylacetonate (Fe(C5H8O2)3) and aloe vera plant-extracted solution. The influences of different reaction temperatures and times on the structure and magnetic properties of the synthesized Fe3O4 nanoparticles were investigated. The synthesized nanoparticles are crystalline and have particle sizes of ˜6-30 nm, as revealed by transmission electron microscopy (TEM). The results of X-ray diffraction (XRD), High resolution TEM (HRTEM) and selected area electron diffraction (SAED) indicate that the synthesized Fe3O4 nanoparticles have the inverse cubic spinel structure without the presence of any other phase impurities. The hysteresis loops of the Fe3O4 nanoparticles at room temperature show superparamagnetic behavior and the saturation magnetization of the Fe3O4 samples increases with increasing reaction temperature and time.

  13. Minimally non-local nucleon-nucleon potentials with chiral two-pion exchange including Δ’s

    Directory of Open Access Journals (Sweden)

    Piarulli Maria

    2016-01-01

    Full Text Available A coordinate-space nucleon-nucleon potential is constructed in chiral effective field theory (χEFT retaining pions, nucleons and Δ-isobars as explicit degrees of freedom. The calculation of the potential is carried out by including one- and two-pionexchange contributions up to next-to-next-to-leading order (N2LO and contact interactions up to next-to-next-to-next-to-leading order (N3LO. The low-energy constants multiplying these contact interactions are fitted to the 2013 Granada database in the laboratory-energy range 0–300 MeV.

  14. Review of Nucleon Decay Searches at Super-Kamiokande

    CERN Document Server

    Takhistov, Volodymyr

    2016-01-01

    Baryon number violation appears in many contexts. It is a requirement for baryogenesis and is a consequence of Grand Unified Theories (GUTs), which predict nucleon decay. Nucleon decay searches provide the most direct way to test baryon number conservation and also serve as a unique probe of GUT scale physics around $10^{14-16}$ GeV. Such energies cannot be reached directly by accelerators. However, they can be explored indirectly at large underground water Cherenkov (WC) experiments, which due to the size of their fiducial volume are highly sensitive to nucleon decays. We review searches for baryon number violating processes at the state of the art WC detector, the Super-Kamiokande. Analyses of the typically dominant non-SUSY and SUSY nucleon decay channels such as $p \\rightarrow (e^+, \\mu^+) \\pi^0$ and $p \\rightarrow \

  15. The parton distributions in nuclei and in polarized nucleons

    Energy Technology Data Exchange (ETDEWEB)

    Close, F.E.

    1988-01-01

    The emerging information was reviewed on the way quark and anti-quark, and gluon distributions are modified in nuclei relative to free nucleons. Some implications of the recent data on polarized leptoproduction are discussed. 27 refs., 6 figs.

  16. Two nucleon (B - L)-conserving reactions involving tau leptons

    Science.gov (United States)

    Bryman, Douglas

    2014-06-01

    Tau lepton emission in two-nucleon disappearance reactions from within nuclei which conserve baryon number minus lepton number (B - L) is considered. It is shown that some existing limits on proton decay channels and two-nucleon disappearance reactions resulting in electrons and muons can be applied to ΔB = ΔL = 2 decays involving τ leptons. For the two-nucleon disappearance channel np →τ+ν‾τ the estimated limit for the partial mean life is τ/Br > 1 ×1030 yrs based on results from the IMB3 experiment. Re-analysis of existing data and future experiments could result in higher sensitivity for two-nucleon disappearance modes involving τ lepton final states.

  17. Nucleon parton distributions in a light-front quark model

    National Research Council Canada - National Science Library

    Gutsche, Thomas; Lyubovitskij, Valery E; Schmidt, Ivan

    2017-01-01

    Continuing our analysis of parton distributions in the nucleon, we extend our light-front quark model in order to obtain both the helicity-independent and the helicity-dependent parton distributions...

  18. Transverse momentum distributions inside the nucleon from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Musch, Bernhard Ulrich

    2009-05-29

    Nucleons, i.e., protons and neutrons, are composed of quarks and gluons, whose interactions are described by the theory of quantum chromodynamics (QCD), part of the standard model of particle physics. This work applies lattice QCD to compute quark momentum distributions in the nucleon. The calculations make use of lattice data generated on supercomputers that has already been successfully employed in lattice studies of spatial quark distributions (''nucleon tomography''). In order to be able to analyze transverse momentum dependent parton distribution functions, this thesis explores a novel approach based on non-local operators. One interesting observation is that the transverse momentum dependent density of polarized quarks in a polarized nucleon is visibly deformed. A more elaborate operator geometry is required to enable a quantitative comparison to high energy scattering experiments. First steps in this direction are encouraging. (orig.)

  19. Preparation of novel curcumin-imprinted polymers based on magnetic multi-walled carbon nanotubes for the rapid extraction of curcumin from ginger powder and kiwi fruit root.

    Science.gov (United States)

    Zhang, Zhaohui; Chen, Xing; Rao, Wei; Long, Fang; Yan, Liang; Yin, Yuli

    2015-01-01

    A novel molecularly imprinted polymer based on magnetic phenyl-modified multi-walled carbon nanotubes was synthesized using curcumin as the template molecule, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linker. The phenyl groups contained in the magnetic imprinted polymers acted as the assisting functional monomer. The magnetic imprinted polymers were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy and vibrating sample magnetometry. Adsorption studies demonstrated that the magnetic imprinted polymers possessed excellent selectivity toward curcumin with a maximum capacity of 16.80 mg/g. Combining magnetic extraction and high-performance liquid chromatography technology, the magnetic imprinted polymer based on magnetic phenyl-modified multi-walled carbon nanotubes was applied for the rapid separation and enrichment of curcumin from ginger powder and kiwi fruit root successfully. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. High Energy Break-Up of Few-Nucleon Systems

    OpenAIRE

    Sargsian, Misak M.

    2008-01-01

    We discus recent developments in theory of high energy two-body break-up reactions of few-nucleon systems. The characteristics of these reactions are such that the hard two-body quasielastic subprocess can be clearly separated from the accompanying soft subprocesses. We discuss in details the hard rescattering model (HRM) in which hard photodisintegration develops in two stages. At first, photon knocks-out an energetic quark which rescatters subsequently with a quark of the other nucleon. The...

  1. Studies of the 3D Structure of the Nucleon at Jlab

    Energy Technology Data Exchange (ETDEWEB)

    Avakian, Harut [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-07-01

    Studies of the 3D structure of the nucleon encoded in Transverse Momentum Dependent distribution and fragmentation functions of partons and Generalized Parton Distributions are among the key objectives of the JLab 12 GeV upgrade and the Electron Ion Collider. Main challenges in extracting 3D partonic distributions from precision measurements of hard scattering processes include clear understanding of leading twist QCD fundamentals, higher twist effects, and also correlations of hadron production in target and current fragmentation regions. In this contribution we discuss some ongoing studies and future measurements of spin-orbit correlations at Jefferson Lab.

  2. Strangeness content and structure function of the nucleon in a statistical quark model

    CERN Document Server

    Trevisan, L A; Tomio, L

    1999-01-01

    The strangeness content of the nucleon is determined from a statistical model using confined quark levels, and is shown to have a good agreement with the corresponding values extracted from experimental data. The quark levels are generated in a Dirac equation that uses a linear confining potential (scalar plus vector). With the requirement that the result for the Gottfried sum rule violation, given by the new muon collaboration (NMC), is well reproduced, we also obtain the difference between the structure functions of the proton and neutron, and the corresponding sea quark contributions. (27 refs).

  3. A phenomenological determination of the pion-nucleon scattering lengths from pionic hydrogen

    CERN Document Server

    Ericson, Torleif Eric Oskar; Wycech, S

    2005-01-01

    A model independent expression for the electromagnetic corrections to a phenomenological hadronic pion-nucleon scattering length, extracted from pionic hydrogen, is obtained. In a non-relativistic approach and using an extended charge distribution, these corrections are derived up to terms of order (alpha)**2 log(alpha) in the limit of a short-range hadronic interaction. We infer a charged pion-proton scattering length of 0.0870(5) in units of inverse pion mass, which gives for the charged pion-proton-neutron coupling, through the GMO relation, a value of 14.04(17).

  4. Experimental studies of nucleon-nucleon and pion-nucleus interactions at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-01

    This report summarizes the work on experimental research in intermediate energy nuclear and particle physics carried out by New Mexico State University in 1988--91. Most of these studies have involved investigations of neutron-proton and pion-nucleus interactions. The neutron-proton research is part of a program of studies of interactions between polarized nucleons that we have been involved with for more than ten years. Its purpose has been to help complete the determination of the full set of ten complex nucleon-nucleon amplitudes at energies up to 800 MeV, as well as to continue investigating the possibility of the existence of dibaryon resonances. The give complex isospin-one amplitudes have been fairly well determined, partly as a result of this work. Our work in this period has involved measurements and analysis of data on elastic scattering and total cross sections for polarized neutrons on polarized protons. The pion-nucleus research continues our studies of this interaction in regions where it has not been well explored. One set of experiments includes studies of pion elastic and double-charge-exchange scattering at energies between 300 and 550 MeV, where our data is unique. Another involves elastic and single-charge-exchange scattering of pions from polarized nuclear targets, a new field of research which will give the first extensive set of information on spin-dependent pion-nucleus amplitudes. Still another involves the first set of detailed studies of the kinematic correlations among particles emitted following pion absorption in nuclei.

  5. Determination of gluon polarisation in the nucleon from events with high-pT hadron pairs in COMPASS experiment

    CERN Document Server

    Klimaszewski, Konrad; Sandacz, A

    The main goal of the COMPASS experiment at CERN is the determination of the gluon spin contribution to the nucleon spin. It is measured using cross section spin asymmetries in Deep Inelastic Scattering of polarised muons off polarised nucleons. The COMPASS uses polarised muon beam of 160 GeV energy and a polarised 6LiD target. The gluons in the nucleon are accessed through a Photon Gluon Fusion process which is tagged by two signatures: an open charm production and pairs of hadrons with high transverse momenta. In this thesis we present the latter analysis performed for the Q2 > 1 GeV2 region and based on the data collected during 2002-2004 years. A novel method of G=G extraction based on Neural Networks is discussed. The result G=G = 0:08 0:1(stat:) 0:05(syst:) is consistent with zero within the measurement uncertainty. It is compatible with other lepton-nucleon scattering results (COMPASS, SMC, HERMES) and with results from the proton-proton interactions (STAR, PHENIX). The obtained result is currently on...

  6. In-medium NN interactions and nucleon and meson masses studied with nucleon knockout reactions

    CERN Document Server

    Noro, T; Akiyoshi, H; Daito, I; Fujimura, H; Hatanaka, K; Ihara, F; Ishikawa, T; Ito, M; Kawabata, M; Kawabata, T; Maeda, Y; Matsuoka, N; Morinobu, S; Nakamura, M; Obayashi, E; Okihana, A; Sagara, K; Sakaguchi, H; Takeda, H; Taki, T; Tamii, A; Tamura, K; Yamazaki, H; Yoshida, H; Yoshimura, M; Yosoi, M

    2000-01-01

    Spin observables have been measured for (p, 2p) reactions aiming at studying medium effects on NN interactions in nuclear field. Observed strong density-dependent reduction of the analyzing power is consistent with a model calculation where reduction of nucleon and meson masses are taken into account. On the other hand, calculations with g-matrices in the Shroedinger framework does not predict the reduction. The spin-transfer coefficients, which data are not reproduced by the model calculation, are found to be sensitive to reduction rate of each meson mass and have a possibility to test scaling lows in mass reductions.

  7. Global QCD Analysis of the Nucleon Tensor Charge with Lattice QCD Constraints

    Science.gov (United States)

    Shows, Harvey, III; Melnitchouk, Wally; Sato, Nobuo

    2017-09-01

    By studying the parton distribution functions (PDFs) of a nucleon, we probe the partonic scale of nature, exploring what it means to be a nucleon. In this study, we are interested in the transversity PDF-the least studied of the three collinear PDFs. By conducting a global analysis on experimental data from semi-inclusive deep inelastic scattering (SIDIS), as well as single-inclusive e+e- annihilation (SIA), we extract the fit parameters needed to describe the transverse moment dependent (TMD) transversity PDF, as well as the Collins fragmentation function. Once the collinear transversity PDF is obtained by integrating the extracted TMD PDF, we wish to resolve discrepancies between lattice QCD calculations and phenomenological extractions of the tensor charge from data. Here we show our results for the transversity distribution and tensor charge. Using our method of iterative Monte Carlo, we now have a more robust understanding of the transversity PDF. With these results we are able to progress in our understanding of TMD PDFs, as well as testify to the efficacy of current lattice QCD calculations. This work is made possible through support from NSF award 1659177 to Old Dominion University.

  8. Spin Asymmetry on the Nucleon Experiment

    Science.gov (United States)

    Maxwell, James

    2007-04-01

    The Spin Asymmetry on the Nucleon Experiment (SANE) will employ a revolutionary increase in Figure of Merit to obtain precise g^p2 and A^p1 results at high x. Using the highest available JLab beam energy, a 194 msr electromagnetic calorimeter will view the UVa polarized NH3 target at 8.5 .10^34 proton luminosity. The large Bjorken x region provides an important view on proton structure where the sea quarks have been stripped away. Using measurements of these ``naked protons'' is crucial for the understanding of strong QCD and can provide a connection between experimentally measured moments of polarized structure functions and quark matrix elements calculated in lattice QCD. The experiment will take place in 2008, using JLab's 5.7 GeV polarized electron beam, and covering the Bjorken x range from 0.3 and 0.8 with an average Q^2 of 4.5 GeV^2. We will discuss the physics motivation for SANE as well as the proposed experimental arrangement, and expected results.

  9. Structure and Spin of the Nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Avakian, Harut A. [JLAB

    2014-03-01

    Parton distribution functions, describing longitudinal momentum, helicity and transversity distributions of quarks and gluons, have been recently generalized to account also for transverse degrees of freedom. Two new sets of more general distributions, Transverse Momentum Distributions and Generalized Parton Distributions, were introduced to describe transverse momentum and space distributions of partons. Great progress has been made since then in measurements of different Single Spin Asymmetries (SSAs) in semi-inclusive and hard exclusive processes providing access to TMDs and GPDs, respectively. Facilities world-wide involved in studies of the 3D structure of nucleon include HERMES, COMPASS, BELLE, BaBar, Halls A, B, and C at JLab, and PHENIX and STAR at RHIC (BNL). TMD studies in the Drell-Yan process are also becoming an important part of the program of hadron scattering experiments. Studies of TMDs are also among the main driving forces of the JLab 12-GeV upgrade project, several of the forward upgrade proposals of STAR and PHENIX at RHIC, and future facilities, such as the Electron Ion Collider (EIC), FAIR in Germany, and NICA in Russia. In this contribution we present an overview of the latest developments in studies of parton distributions and discuss newly released results, ongoing activities, as well as some future measurements.

  10. Electromagnetic Studies of Mesons, Nucleons, and Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Oliver K.

    2013-08-20

    Professor Baker was a faculty member at Hampton University in Hampton, Virginia, and, jointly, a Staff Physicist at Jefferson Lab in nearby Newport News from September 1989 to July 2006. The Department of Energy (DOE) funded the grant DE-FG02-97ER41035 Electromagnetic Studies of Mesons, Nucleons, and Nuclei, while Baker was in this joint appointment. Baker sent a closeout report on these activities to Hampton University’s Sponsored Research Office some years ago, shortly after joining Yale University in 2006. In the period around 2001, the research grant with Baker as the Principal Investigator (PI) was put under the supervision of Professor Liguang Tang at Hampton University. Baker continued to pursue the research while in this join appointment, however the administrative responsibilities with the DOE and with Hampton University rested with Professor Tang after 2001, to my recollection. What is written in this document is from Baker’s memory of the research activities, which he has not pursued since joining the Yale University faculty.

  11. Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

    DEFF Research Database (Denmark)

    Kistrup, Kasper; Sørensen, Karen Skotte; Wolff, Anders

    2014-01-01

    We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible...... phase filtration and features passive liquid filling and magnetic bead manipulation using an external magnet. In this work, we determine the system compatibility with various surfactants. Moreover, we quantify the volume of liquid co-transported with magnetic bead clusters from Milli-Q water or a lysis...

  12. Closed form S matrix in terms of matter distributions and nucleon-nucleon interaction for heavy ion scattering

    Energy Technology Data Exchange (ETDEWEB)

    Gambhir, Y.K.; Shastry, C.S.

    1984-10-01

    We derive an approximate analytical expression for the S matrix in terms of the parameters of the nuclear matter distributions and nucleon-nucleon interaction in the framework of folding model for heavy ion scattering. The numerical calculations carried out for /sup 18/O+ /sup 58/Ni scattering (E/sub lab/ = 60 MeV), a test case, agree well with the corresponding results of the phenomenological optical model.

  13. Permanent Magnets In Steerers Of The Beam Extracted From The Electron Accelerator

    CERN Document Server

    Dovbnya, A N; Shendrik, V A; Tolstoj, A E

    2004-01-01

    The results of test bench simulation and magnetic measurements were used to develop and manufacture "dipole magnet"-type units with a constant field of intensity up to 1.8 kOe in the working gap, 3 to 3.5 cm in height. The operating experience at the technological accelerators has shown that these devices are convenient in service, are easy-to-transport and can be used for solving the various problems in electron beam formation and steering at the exit of the accelerator.

  14. Automatic Mapping Extraction from Multiecho T2-Star Weighted Magnetic Resonance Images for Improving Morphological Evaluations in Human Brain

    Directory of Open Access Journals (Sweden)

    Shaode Yu

    2013-01-01

    Full Text Available Mapping extraction is useful in medical image analysis. Similarity coefficient mapping (SCM replaced signal response to time course in tissue similarity mapping with signal response to TE changes in multiecho T2-star weighted magnetic resonance imaging without contrast agent. Since different tissues are with different sensitivities to reference signals, a new algorithm is proposed by adding a sensitivity index to SCM. It generates two mappings. One measures relative signal strength (SSM and the other depicts fluctuation magnitude (FMM. Meanwhile, the new method is adaptive to generate a proper reference signal by maximizing the sum of contrast index (CI from SSM and FMM without manual delineation. Based on four groups of images from multiecho T2-star weighted magnetic resonance imaging, the capacity of SSM and FMM in enhancing image contrast and morphological evaluation is validated. Average contrast improvement index (CII of SSM is 1.57, 1.38, 1.34, and 1.41. Average CII of FMM is 2.42, 2.30, 2.24, and 2.35. Visual analysis of regions of interest demonstrates that SSM and FMM show better morphological structures than original images, T2-star mapping and SCM. These extracted mappings can be further applied in information fusion, signal investigation, and tissue segmentation.

  15. Three-dimensional ionic liquid functionalized magnetic graphene oxide nanocomposite for the magnetic dispersive solid phase extraction of 16 polycyclic aromatic hydrocarbons in vegetable oils.

    Science.gov (United States)

    Zhang, Yun; Zhou, Hua; Zhang, Zhe-Hua; Wu, Xiang-Lun; Chen, Wei-Guo; Zhu, Yan; Fang, Chun-Fu; Zhao, Yong-Gang

    2017-03-17

    In this paper, a novel three-dimensional ionic liquid functionalized magnetic graphene oxide nanocomposite (3D-IL@mGO) was prepared, and used as an effective adsorbent for the magnetic dispersive solid phase extraction (MSPE) of 16 polycyclic aromatic hydrocarbons (PAHs) in vegetable oil prior to gas chromatography-mass spectrometry (GC-MS). The properties of 3D-IL@mGO were characterized by scanning electron micrographs (SEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM). The 3D-IL@mGO, functionalized by ionic liquid, exhibited high adsorption toward PAHs. Compared to molecularly imprinted solid phase extraction (MISPE), the MSPE method based on 3D-IL@mGO had less solvent consumption and low cost, and was more efficent to light PAHs in quantitative analysis. Furthermore, the rapid and accurate GC-MS method coupled with 3D-IL@mGO MSPE procedure was successfully applied for the analysis of 16 PAHs in eleven vegetable oil samples from supermarket in Zhejiang Province. The results showed that the concentrations of BaP in 3 out of 11 samples were higher than the legal limit (2.0μg/kg, Commission Regulation 835/2011a), the sum of 8 heavy PAHs (BaA, CHR, BbF, BkF, BaP, IcP, DaA, BgP) in 11 samples was between 3.03μg/kg and 229.5μg/kg. Validation results on linearity, specificity, accuracy, precision and stability, as well as on application to the analysis of PAHs in oil samples demonstrated the applicability to food safety risk monitoring in China. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Modeling a nucleon system: static and dynamical properties - density fluctuations; Modelisation d`un system de nucleons: proprietes statiques et dynamiques - fluctuation de densite

    Energy Technology Data Exchange (ETDEWEB)

    Idier, D. [Nantes Univ., 44 (France)

    1997-02-15

    This thesis sets forth a quasi-particle model for the static and dynamical properties of nuclear matter. This model is based on a scale ratio of quasi-particle to nucleons and the projection of the semi-classical distribution on a coherent Gaussian state basis. The first chapter is dealing with the transport equations, particularly with the Vlasov equation for Wigner distribution function. The second one is devoted to the statics of nuclear matter. Here, the sampling effect upon the nuclear density is treated and the state equation of the Gaussian fluid is compared with that given by Hartree-Fock approximation. We define state equation as the relationship between the nucleon binding energy and density, for a given temperature. The curvature around the state equation minimum of the quasi-particle system is shown to be related to the speed of propagation of density perturbation. The volume energy and the surface properties of a (semi-)infinite nucleon system are derived. For the resultant saturated auto-coherent semi-infinite system of quasi-particles the surface coefficient appearing in the mass formula is extracted as well as the system density profile. The third chapter treats the dynamics of the two-particle residual interactions. The effect of different parameters on relaxation of a nucleon system without a mean field is studied by means of a Eulerian and Lagrangian modeling. The fourth chapter treats the volume instabilities (spinodal decomposition) in nuclear matter. The quasi-particle systems, initially prepared in the spinodal region of the utilized interaction, are set to evolve. It is shown then that the scale ratio acts upon the amount of fluctuations injected in the system. The inhomogeneity degree and a proper time are defined and the role of collisions in the spinodal decomposition as well as that of the initial temperature and density, are investigated. Assuming different effective macroscopic interactions, the influence of quantities as

  17. Di-nucleon structures in homogeneous nuclear matter based on two- and three-nucleon interactions

    Energy Technology Data Exchange (ETDEWEB)

    Arellano, Hugo F. [University of Chile, Department of Physics - FCFM, Santiago (Chile); CEA, DAM, DIF, Arpajon (France); Isaule, Felipe [University of Chile, Department of Physics - FCFM, Santiago (Chile); Rios, Arnau [University of Surrey, Department of Physics, Faculty of Engineering and Physical Sciences, Guildford (United Kingdom)

    2016-09-15

    We investigate homogeneous nuclear matter within the Brueckner-Hartree-Fock (BHF) approach in the limits of isospin-symmetric nuclear matter (SNM) as well as pure neutron matter at zero temperature. The study is based on realistic representations of the internucleon interaction as given by Argonne v{sub 18}, Paris, Nijmegen I and II potentials, in addition to chiral N{sup 3}LO interactions, including three-nucleon forces up to N{sup 2}LO. Particular attention is paid to the presence of di-nucleon bound states structures in {sup 1}S{sub 0} and {sup 3}SD{sub 1} channels, whose explicit account becomes crucial for the stability of self-consistent solutions at low densities. A characterization of these solutions and associated bound states is discussed. We confirm that coexisting BHF single-particle solutions in SNM, at Fermi momenta in the range 0.13-0.3 fm{sup -1}, is a robust feature under the choice of realistic internucleon potentials. (orig.)

  18. Relativistic extended Thomas-Fermi calculations of finite nuclei with realistic nucleon-nucleon interactions

    Energy Technology Data Exchange (ETDEWEB)

    Centelles, M.; Vinas, X.; Barranco, M. (Departament d' Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain)); Ohtsuka, N.; Faessler, A.; Khoa, D.T.; Muether, H. (Institut fuer Theoretische Physik, Universitaet Tuebingen, Auf der Morgenstelle 14, D-7400 Tuebingen (Germany))

    1993-03-01

    A relativistic energy density functional is constructed to investigate the Dirac effects on different properties of the structure and scattering of finite nuclei. The kinetic energy density has been derived within a relativistic extended Thomas-Fermi model and includes gradient corrections to second order in [h bar]. The effective mass and the volume term of the potential energy density have been obtained from a local density approximation to Dirac-Brueckner calculations of nuclear matter carried out with a realistic nucleon-nucleon interaction. This volume term is supplemented by the Coulomb energy and by conventional phenomenological surface and symmetry terms, and the few free parameters of the functional are suitably adjusted. Attention is then focused on the calculation of fission barriers of rotating nuclei and of the complex optical potential for heavy ion collisions at intermediate energies. It turns out that the effects of the density-dependent Dirac spinor which have been incorporated in this approach allow for a reasonable description of the investigated properties.

  19. Magnetic Solid Phase Extraction and Removal of Five Cationic Dyes from Aqueous Solution Using Magnetite Nanoparticle Loaded Platanusorientalis Waste Leaves

    Directory of Open Access Journals (Sweden)

    Elaheh Madrakian

    2016-12-01

    Full Text Available This paper reports on synthesis of a magnetic adsorbent for wastewater treatment purposes. In this regard, platanus orientalis waste leaves were chosen as a cheap material for preparing the magnetic adsorbent by loading magnetite nanoparticles on it. The synthesized adsorbent was characterized using scanning electron microscope and X-ray diffractometer. Then, it was used for magnetic solid phase extraction and removal of five cationic dyes including methyl violet (MV, methylene blue (MB, malachite green (MG, crystal violet (CV, and neutral red (NR from aqueous solution as a model application. Different important factors affecting the adsorption process were optimized, and the results showed that under the optimized conditions (pH 10 for CV, MV, MB, and MG; pH 6 for NR; adsorbent dosage, 20 mg; agitation time, 25 min efficient removal of the investigated dyes (adsorption capacities between of 89-133 mg g-1 is achievable using the synthesized adsorbent. Furthermore, the reusability experiments showed that the adsorbent could be reused at least ten cycles without any significant loss in its sorption behavior.

  20. Bonner Prize: The Elastic Form Factors of the Nucleon

    Science.gov (United States)

    Perdrisat, Charles F.

    2017-01-01

    A series of experiments initiated in 1998 at the then new Continuous Electron Beam Accelerator, or CEBAF in Newport News Virginia, resulted in unexpected results, changing significantly our understanding of the structure of the proton. These experiments used a relatively new technique to obtain the ratio of the two form factors of the proton, namely polarization. An intense beam of highly polarized electrons with energy up to 6 GeV was made to interact elastically with un-polarized protons in a hydrogen target. The polarization of the recoiling protons, with energies up to 5 GeV, was measured from a second interaction in a polarimeter consisting of blocs of graphite or CH2 and tracking wire chambers. The scattered electrons were detected in an electromagnetic lead-glass calorimeter, to select elastically scattered events. After a short introduction describing the path which brought me from the University of Geneva to the College of William and Mary in 1966, I will introduce the subject of elastic electron scattering, describe some of the apparatus required for such experiments, and show the results which were unexpected at the time. These results demonstrated unequivocally that the two form factors required to describe elastic ep scattering, electric GE and magnetic GM in the Born approximation, had a drastically different dependence upon the four-momentum squared q2 = q2 -ω2 with q the momentum, and ω the energy transferred in the reaction. The finding, in flagrant disagreement with the data available at the time, which had been obtained dominantly from cross section measurements of the type first used by Nobel Prize R. Hofstadter 60 years ago, have led to a reexamination of the information provided by form factors on the structure of the nucleon, in particular its quark-gluon content. The conclusion will then be a brief outline of several theoretical considerations to put the results in a proper perspective.

  1. Universality of many-body two-nucleon momentum distributions: Correlated nucleon spectral function of complex nuclei

    Science.gov (United States)

    Ciofi degli Atti, Claudio; Morita, Hiko

    2017-12-01

    Background: The nuclear spectral function is a fundamental quantity that describes the mean-field and short-range correlation dynamics of nucleons embedded in the nuclear medium; its knowledge is a prerequisite for the interpretation of various electroweak scattering processes off nuclear targets aimed at providing fundamental information on strong and weak interactions. Whereas in the case of the three-nucleon and, partly, the four-nucleon systems, the spectral function can be calculated ab initio within a nonrelativistic many-body Schroedinger approach, in the case of complex nuclei only models of the correlated, high-momentum part of the spectral function are available so far. Purpose: The purpose of this paper is to present a new approach such that the spectral function for a specific nucleus can be obtained from a reliable many-body calculation based upon realistic nucleon-nucleon interactions, thus avoiding approximations leading to adjustable parameters. Methods: The expectation value of the nuclear many-body Hamiltonian, containing realistic nucleon-nucleon interaction of the Argonne family, is evaluated variationally by a normalization-conserving linked-cluster expansion and the resulting many-body correlated wave functions are used to calculate the one-nucleon and the two-nucleon momentum distributions; by analyzing the high-momentum behavior of the latter, the spectral function can be expressed in terms of a transparent convolution formula involving the relative and center-of-mass (c.m.) momentum distributions in specific regions of removal energy E and momentum k . Results: It is found that as a consequence of the factorization of the many-body wave functions at short internucleon separations, the high-momentum behavior of the two-nucleon momentum distributions in A =3 ,4 ,12 ,16 ,40 nuclei factorizes, at proper values of the relative and c.m. momenta, into the c.m. and relative momentum distributions, with the latter exhibiting a universal A

  2. The evaluation of magnetic polymethacrylate-based microspheres used for solid phase DNA micro-extraction

    Czech Academy of Sciences Publication Activity Database

    Trachtová, Š.; Zapletalová, H.; Španová, A.; Horák, Daniel; Kolářová, H.; Rittich, B.

    2015-01-01

    Roč. 2, č. 2 (2015), s. 156-166 ISSN 2227-9075 R&D Projects: GA ČR GAP206/12/0381 Institutional support: RVO:61389013 Keywords : magnetic microspheres * quantitative polymerase chain reaction * inhibitory effect Subject RIV: EB - Genetics ; Molecular Biology

  3. Extracting Ocean-Generated Tidal Magnetic Signals from Swarm Data Through Satellite Gradiometry

    Science.gov (United States)

    Sabaka, Terence J.; Tyler, Robert H.; Olsen, Nils

    2016-01-01

    Ocean-generated magnetic field models of the Principal Lunar, M2, and the Larger Lunar elliptic, N2, semidiurnal tidal constituents were estimated through a "Comprehensive Inversion" of the first 20.5 months of magnetic measurements from European Space Agency's (ESA) Swarm satellite constellation mission. While the constellation provides important north-south along-track gradiometry information, it is the unique low-spacecraft pair that allows for east-west cross-track gradiometry. This latter type is crucial in delivering an M2 estimate of similar quality with that derived from over 10 years of CHAMP satellite data but over a shorter interval, at higher altitude, and during more magnetically disturbed conditions. Recovered N2 contains nonoceanic signal but is highly correlated with theoretical models in regions of maximum oceanic amplitude. Thus, satellite magnetic gradiometry may eventually enable the monitoring of ocean electrodynamic properties at temporal resolutions of 1 to 2 years, which may have important implications for the inference of ocean temperature and salinity.

  4. One-step synthesis of magnetic graphene oxide nanocomposite and its application in magnetic solid phase extraction of heavy metal ions from biological samples.

    Science.gov (United States)

    Sun, Jieping; Liang, Qionglin; Han, Qiang; Zhang, Xiaoqiong; Ding, Mingyu

    2015-01-01

    A novel magnetic graphene oxide nanocomposite was synthesized by one-step coprecipitation method and characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and vibrating sample magnetometer. The nanocomposite beard many intriguing properties, including chemical stability, high adsorption capacity, and superparamagnetic. These properties evoked great interest and desire of its exploration in magnetic solid-phase extraction of heavy metal ions from complex samples. Several parameters effecting the analytical performance, such as the sample pH, amounts of adsorbent, sample volumes, elution volumes, and coexisting ions, had been investigated in detail. The adsorbed metal ions were easy eluted by controlling the pH condition and the materials could be reused more than 20 times. Under the optimized conditions, the limits of detection were 0.016, 0.046, 0.395, 0.038, 0.157 μg L(-1) for Co(2+), Ni(2+), Cu(2+), Cd(2+), and Pb(2+), respectively. The intra-day relative standard deviations (n=5) were in the range of 1.8-5.5% at 10 μg L(-1). The proposed method was successfully applied to biological sample analysis and got excellent recoveries in the range of 81-113% even the matrix was complex. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Kistrup, Kasper, E-mail: kkis@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Skotte Sørensen, Karen, E-mail: karen@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Center for Integrated Point of Care Technologies (CiPoC), DELTA, Venlighedsvej 4, DK-2870 Hørsholm (Denmark); Wolff, Anders, E-mail: anders.wolff@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Fougt Hansen, Mikkel, E-mail: mikkel.hansen@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark)

    2015-04-15

    We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible phase filtration and features passive liquid filling and magnetic bead manipulation using an external magnet. In this work, we determine the system compatibility with various surfactants. Moreover, we quantify the volume of liquid co-transported with magnetic bead clusters from Milli-Q water or a lysis-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/µg and 1.72(14) nL/µg were found for Milli-Q water and lysis-binding buffer, respectively. - Highlights: • We present an all-polymer mass producible passive filled microfluidic chip system. • Rapid system fabrication is obtained by injection moulding and ultrasonic welding. • The system is made for single-use nucleic acid extraction using magnetic beads. • We systematically map compatibility of the chip system with various surfactants. • We quantify the volume carry-over of magnetic beads in water and 0.1% triton-X solution.

  6. Automatic segmentation of the bone and extraction of the bone-cartilage interface from magnetic resonance images of the knee

    Energy Technology Data Exchange (ETDEWEB)

    Fripp, Jurgen [BioMedIA Lab, Autonomous Systems Laboratory, CSIRO ICT Centre, Level 20, 300 Adelaide street, Brisbane, QLD 4001 (Australia); Crozier, Stuart [School of Information Technology and Electrical Engineering, University of Queensland, St Lucia, QLD 4072 (Australia); Warfield, Simon K [Computational Radiology Laboratory, Harvard Medical School, Children' s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115 (United States); Ourselin, Sebastien [BioMedIA Lab, Autonomous Systems Laboratory, CSIRO ICT Centre, Level 20, 300 Adelaide street, Brisbane, QLD 4001 (Australia)

    2007-03-21

    The accurate segmentation of the articular cartilages from magnetic resonance (MR) images of the knee is important for clinical studies and drug trials into conditions like osteoarthritis. Currently, segmentations are obtained using time-consuming manual or semi-automatic algorithms which have high inter- and intra-observer variabilities. This paper presents an important step towards obtaining automatic and accurate segmentations of the cartilages, namely an approach to automatically segment the bones and extract the bone-cartilage interfaces (BCI) in the knee. The segmentation is performed using three-dimensional active shape models, which are initialized using an affine registration to an atlas. The BCI are then extracted using image information and prior knowledge about the likelihood of each point belonging to the interface. The accuracy and robustness of the approach was experimentally validated using an MR database of fat suppressed spoiled gradient recall images. The (femur, tibia, patella) bone segmentation had a median Dice similarity coefficient of (0.96, 0.96, 0.89) and an average point-to-surface error of 0.16 mm on the BCI. The extracted BCI had a median surface overlap of 0.94 with the real interface, demonstrating its usefulness for subsequent cartilage segmentation or quantitative analysis.

  7. High-precision calculation of the strange nucleon electromagnetic form factors

    Energy Technology Data Exchange (ETDEWEB)

    Green, Jeremy [Johannes Gutenberg Univ., Mainz (Germany); Meinel, Stefan [Univ. of Arizona, Tucson, AZ (United States); Brookhaven National Lab. (BNL), Upton, NY (United States); Engelhardt, Michael G. [New Mexico State Univ., Las Cruces, NM (United States); Krieg, Stefan [Bergische Univ., Wuppertal (Germany); Julich Supercomputing Centre, Julich (Germany); Laeuchli, Jesse [College of William and Mary, Williamsburg, VA (United States); Negele, John W. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Orginos, Kostas [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Pochinsky, Andrew [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Syritsyn, Sergey [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-08-26

    We report a direct lattice QCD calculation of the strange nucleon electromagnetic form factors GsE and GsM in the kinematic range 0 ≤ Q2 ≤ 1.2GeV2. For the first time, both GsE and GsM are shown to be nonzero with high significance. This work uses closer-to-physical lattice parameters than previous calculations, and achieves an unprecented statistical precision by implementing a recently proposed variance reduction technique called hierarchical probing. We perform model-independent fits of the form factor shapes using the z-expansion and determine the strange electric and magnetic radii and magnetic moment. As a result, we compare our results to parity-violating electron-proton scattering data and to other theoretical studies.

  8. MAGNET

    CERN Multimedia

    by B. Curé

    2011-01-01

    The magnet operation was very satisfactory till the technical stop at the end of the year 2010. The field was ramped down on 5th December 2010, following the successful regeneration test of the turbine filters at full field on 3rd December 2010. This will limit in the future the quantity of magnet cycles, as it is no longer necessary to ramp down the magnet for this type of intervention. This is made possible by the use of the spare liquid Helium volume to cool the magnet while turbines 1 and 2 are stopped, leaving only the third turbine in operation. This obviously requires full availability of the operators to supervise the operation, as it is not automated. The cryogenics was stopped on 6th December 2010 and the magnet was left without cooling until 18th January 2011, when the cryoplant operation resumed. The magnet temperature reached 93 K. The maintenance of the vacuum pumping was done immediately after the magnet stop, when the magnet was still at very low temperature. Only the vacuum pumping of the ma...

  9. Overview of the nucleon spin studies at COMPASS

    Directory of Open Access Journals (Sweden)

    Franco Celso

    2014-04-01

    Full Text Available The COMPASS experiment [1] at CERN is one of the leading experiments studying the spin structure of the nucleon. These studies are being carried on since 2002, by measuring hadrons produced in deep inelastic scattering (DIS of 160 GeV/c polarised muons off different polarised targets (NH3 for polarised protons and 6LiD for polarised deuterons. One of the main goals is to determine how the total longitudinal spin projection of the nucleon, 1/2, is distributed among its constituents, quarks and gluons. We review here the recent results on the quark and gluon helicities obtained by COMPASS, using a longitudinally polarised target. However, the understanding of the nucleon (spin structure based only on the parton helicities is not in any way complete. It basically provides us with a one-dimensional picture in a longitudinal momentum space. Therefore, COMPASS also studies the transverse momentum dependent parton distributions (TMDs with a transversely polarised target. Concerning the TMDs, the latest results on the Collins and Sivers asymmetries will be shown. The former is sensitive to the transverse spin structure of the nucleon, while the latter reflects the correlations between the quarks transverse momentum and the nucleon spin.

  10. Dispersion-theoretical analysis of the nucleon electromagnetic form factors

    Energy Technology Data Exchange (ETDEWEB)

    Belushkin, M.

    2007-09-29

    The structure of the proton and the neutron is of fundamental importance for the study of the strong interaction dynamics over a wide range of momentum transfers. The nucleon form factors encode information on the internal structure of the nucleon as probed by the electromagnetic interaction, and, to a certain extent, reflect the charge and magnetisation distributions within the proton and the neutron. In this thesis we report on our investigation of the electromagnetic form factors of the proton and the neutron with dispersion relation techniques, including known experimental input on the {pi}{pi}, K anti K and the {rho}{pi} continua and perturbative QCD constraints. We include new experimental data on the pion form factor and the nucleon form factors in our simultaneous analysis of all four form factors in both the space- and the timelike regions for all momentum transfers, and perform Monte- Carlo sampling in order to obtain theoretical uncertainty bands. Finally, we discuss the implications of our results on the pion cloud of the nucleon, the nucleon radii and the Okubo-Zweig-Iizuka rule, and present our results of a model-independent approach to estimating two-photon effects in elastic electron-proton scattering. (orig.)

  11. A novel nuclear dependence of nucleon–nucleon short-range correlations

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Hongkai [College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Wang, Rong, E-mail: rwang@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Lanzhou University, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Huang, Yin [Lanzhou University, Lanzhou 730000 (China); Chen, Xurong [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2017-06-10

    A linear correlation is found between the magnitude of nucleon–nucleon short-range correlations and the nuclear binding energy per nucleon with pairing energy removed. By using this relation, the strengths of nucleon–nucleon short-range correlations of some unmeasured nuclei are predicted. Discussions on nucleon–nucleon pairing energy and nucleon–nucleon short-range correlations are made. The found nuclear dependence of nucleon–nucleon short-range correlations may shed some lights on the short-range structure of nucleus.

  12. Generalized parton distributions and transverse densities in a light-front quark-diquark model for the nucleons

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, Chandan; Chakrabarti, Dipankar [Indian Institute of Technology Kanpur, Department of Physics, Kanpur (India)

    2015-06-15

    We present a study of the generalized parton distributions (GPDs) for the quarks in a proton in both momentum and position spaces using the light-front wave functions (LFWFs) of a quark-diquark model for the nucleon predicted by the soft-wall model of AdS/QCD. The results are compared with the soft-wall AdS/QCD model of proton GPDs for zero skewness. We also calculate the GPDs for nonzero skewness. We observe that the GPDs have a diffraction pattern in longitudinal position space, as seen before in other models. Then we present a comparative study of the nucleon charge and anomalous magnetization densities in the transverse plane. Flavor decompositions of the form factors and transverse densities are also discussed. (orig.)

  13. Magnetic polyethyleneimine functionalized reduced graphene oxide as a novel magnetic solid-phase extraction adsorbent for the determination of polar acidic herbicides in rice

    Energy Technology Data Exchange (ETDEWEB)

    Li, Na [Key Laboratory of Chemistry of Northwestern Plant Resources of the CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China); University of Chinese Academy of Sciences, Beijing, 100039 (China); Chen, Juan, E-mail: chenjuan@licp.cas.cn [Key Laboratory of Chemistry of Northwestern Plant Resources of the CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China); Shi, Yan-Ping, E-mail: shiyp@licp.cas.cn [Key Laboratory of Chemistry of Northwestern Plant Resources of the CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China)

    2017-01-01

    A novel magnetic polyethyleneimine modified reduced graphene oxide (Fe{sub 3}O{sub 4}@PEI-RGO) had been fabricated based on a self-assemble approach between positive charged magnetic polyethyleneimine (Fe{sub 3}O{sub 4}@PEI) and negative charged GO sheets via electrostatic interaction followed by chemical reduction of GO to RGO. The as-prepared Fe{sub 3}O{sub 4}@PEI-RGO was characterized by transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD), thermal gravimetric analyzer (TGA), vibrating sample magnetometer (VSM) and zeta potential analysis, and then was successfully applied to determine four phenoxy acid herbicides and dicamba in rice coupled with high performance liquid chromatography (HPLC). As a surface modifier of RGO, PEI not only effectually affected the surface property of RGO (e.g. zeta potential), but also changed the polarity of RGO and offered anion exchange groups to polar acidic herbicides, which would directly influence the type of adsorbed analytes. Compared with Fe{sub 3}O{sub 4}@PEI, Fe{sub 3}O{sub 4}/RGO and Fe{sub 3}O{sub 4}@PEI-GO, the as-prepared Fe{sub 3}O{sub 4}@PEI-RGO, integrating the superiority of PEI and RGO, showed higher extraction efficiency for polar acidic herbicides. Besides, the adsorption mechanism was investigated as well. It turned out that electrostatic interaction and π-π interaction were considered to be two major driving force for the adsorption process. Response surface methodology (RSM), a multivariate experimental design technique, was used to optimize experimental parameters affecting the extraction efficiency in detail. Under the optimal conditions, a satisfactory performance was obtained. The calibration curves were linear over the concentration ranging from 2 to 300 ng g{sup −1} with correlation coefficients (r) between 0.9985 and 0.9994. The limits of detection (LODs) were in the range of 0.67–2 ng g{sup −1}. The recoveries ranged from 87

  14. Multicore Magnetic Nanoparticles Coated with Oligomeric Micelles: Characterization and Potential for the Extraction of Contaminants over a Wide Polarity Range.

    Science.gov (United States)

    Naous, Mohamed; García-Gómez, Diego; López-Jiménez, Francisco José; Bouanani, Farida; Lunar, María Loreto; Rubio, Soledad

    2017-01-17

    Oligomeric micelles from sodium undecylenate (oSUD) were chemisorbed to magnetic iron oxide nanoparticles (MNPs) through a single-step synthetic route involving the simultaneous nanoparticle formation and functionalization in an aqueous medium. The resulting spherical nanoparticles (MNPs-oSUD) consisted of a concatenation of iron oxide cores, with an average size of 7.7 nm, bound by oSUD micelles (particle average diameter of ca. 200 nm). Micellar coverage was ∼50% of the MNP-oSUD (by weight) and offered multiple retention mechanisms (e.g., dispersion, hydrogen bonding, polar, and ionic) for solute solubilization while keeping it intact during analyte elution. The high density of micelles and variety of interactions provided by this sorbent rendered it highly efficient for the extraction of aromatic amines in a wide polarity range (log K ow values from -0.80 to 4.05) from textiles, urine, and wastewater. Extraction took 5 min, no cleanup or evaporation of the extracts was needed and the method, based on LC-MS/MS quantitation, proved matrix-independent. Recoveries for 17 aromatic amines in samples were in the range of 93%-123% while those with negative log K ow values were in the range of 69%-87%. Detection limits for aromatic amines in textiles (0.007-2 mg kg -1 ) were well below the limits legislated by the European Union (EU) (30 mg kg -1 ) and those in urine and wastewater (0.004-1.5 μg L -1 ) were at the level usually found in real-world applications. All the analyzed samples were positive in aromatic amines. The easy synthesis and excellent extraction properties of MNPs-oSUD anticipate their high potential not only for multiresidue analysis but also in other fields such as water remediation.

  15. Extraction of negative pionlike particles from a H{sub 2} or D{sub 2} gas discharge plasma in magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Uramoto, Joshin

    1995-09-01

    Electron density in outside region of H{sub 2} or D{sub 2} gas discharge plasma along magnetic field, is abruptly reduced as H{sup -} or D{sup -} ions are produced. From the region, negative pionlike particles are extracted together with H{sup -} or D{sup -} ions. Then, a positive bias voltage is necessary for the beam collector of magnetic mass analyzer. (author).

  16. Superparamagnetic adsorbents for high-gradient magnetic fishing of lectins out of legume extracts

    DEFF Research Database (Denmark)

    Heebøll-Nielsen, Anders; Dalkiær, M.; Hubbuch, Jürgen

    2004-01-01

    affinity supports created by direct attachment of glucose or maltose to amine-terminated iron oxide particles could bind concanavalin A at levels of up to approximate to 280 mg g(-1) support with high affinity (approximate to 1 muM dissociation constants). However, the best performance was delivered...... by adsorbents featuring coupled tentacular dextran chains displaying a maximum binding capacity of 238 mg g(-1) and a dissociation constant of 0.13 muM. Adsorbents derivatized with mixed mode or hydrophobic charge induction ligands likewise demonstrated very high capacities for both concanavalin A and Lens...... culinaris agglutinin (greater than or equal to 250 mg g(-1)) with dissociation constants in the micromolar range, though neither of these systems showed any selectivity for lectins in leguminous extracts. When the affinity supports were applied to carbohydrate containing legume extracts only the dextran...

  17. Analysis of lipids in crude extracts by 13C nuclear magnetic resonance.

    Science.gov (United States)

    Pollesello, P; Toffanin, R; Eriksson, O; Kilpeläinen, I; Hynninen, P H; Paoletti, S; Saris, N E

    1993-10-01

    Phospho- and glycolipids with mono- or polyunsaturated fatty acid chains, free and acylated steroids, carotenes and carotenoids, chlorophylls, and related pheophytins were detected in crude extracts by NMR spectroscopy without any need for prior separation. A broad range of molecules belonging to different lipid classes could be identified in one-dimensional 13C NMR spectra obtained by applying a polarization transfer pulse sequence (DEPT 135 degrees). Directly detected or 1H-detected two-dimensional heterocorrelated NMR experiments were performed to facilitate the assignment of peaks arising from carotenoids, unsaturated fatty acid chains, and chlorophylls. 13C NMR data of crude lipid extracts from the macroalagae Ulva rigida and Fucus virsoides are shown to yield an informative overview of their lipid content. NMR is thus proposed as a simple, nonselective, and nondestructive technique for the first screening of the main lipid classes in complex lipid mixtures.

  18. Measurement of the weak nucleon-nucleon interaction by polarized cold neutron capture on protons

    Directory of Open Access Journals (Sweden)

    Alarcon R.

    2014-03-01

    Full Text Available The NPDGamma Experiment at the Spallation Neutron Source at Oak Ridge National Laboratory is measuring the parity-odd correlation between the neutron spin and the direction of the emitted photon in the capture of polarized cold neutrons on protons. A parity violating asymmetry from this process is directly related to the strength of the hadronic weak interaction between nucleons. The experiment was run first with heavier nuclear targets to check systematic effects, false asymmetries, and backgrounds. Since early 2012 the experiment has been collecting data with a 16-liter liquid parahydrogen target. Data taking will continue through 2013 until statistics for a 10−8 asymmetry measurement are expected. The experiment performance will be discussed as well as the status of the asymmetry measurements.

  19. The general operator form for the total-momentum-dependent nucleon-nucleon potential

    Energy Technology Data Exchange (ETDEWEB)

    Topolnicki, Kacper; Golak, Jacek; Skibinski, Roman; Witala, Henryk [Jagiellonian University, M. Smoluchowski Institute of Physics, Krakow (Poland)

    2016-07-15

    In this paper we describe a procedure to obtain the general operator form of two-nucleon (2N) potentials and apply it to the case of the 2N potential that has an additional dependence on the total momentum of the system. This violates Galilean invariance but terms including the total momentum appear in some relativistic approaches. In operator form, the potential is expressed as a linear combination of a fixed number of known spin-momentum operators and scalar functions of momenta. Since the scalar functions effectively define the potentials, using the operator form significantly reduces the number of parameters that are needed in numerical implementations. The proposed operator form explicitly obeys the usual symmetries of rotational invariance, particle exchange, time reflection and parity. (orig.)

  20. Coarse graining the Bethe-Goldstone equation: Nucleon-nucleon high-momentum components

    Science.gov (United States)

    Simo, I. Ruiz; Pérez, R. Navarro; Amaro, J. E.; Arriola, E. Ruiz

    2017-11-01

    The δ -shell representation of the nuclear force allows a simplified treatment of nuclear correlations. We show how this applies to the Bethe-Goldstone equation as an integral equation in coordinate space with a few mesh points, which is solved by inversion of a five-dimensional square matrix in the single channel cases and a 10 ×10 matrix for the tensor-coupled channels. This allows us to readily obtain the high-momentum distribution, for all partial waves, of a back-to-back correlated nucleon pair in nuclear matter. We find that the probability of finding a high-momentum correlated neutron-proton pair is about 18 times that of a proton-proton one, as a result of the strong tensor force, thus confirming in an independent way previous results and measurements.

  1. Novel Functionalized Polythiophene-Coated Fe3O4 Nanoparticles for Magnetic Solid-Phase Extraction of Phthalates

    Directory of Open Access Journals (Sweden)

    Siti Nor Atika Baharin

    2016-04-01

    Full Text Available Poly(phenyl-(4-(6-thiophen-3-yl-hexyloxy-benzylidene-amine (P3TArH was successfully synthesized and coated on the surface of Fe3O4 magnetic nanoparticles (MNPs. The nanocomposites were characterized by Fourier transform infra-red (FTIR, X-ray diffractometry (XRD, Brunauer-Emmett-Teller (BET surface area analysis, analyzer transmission electron microscopy (TEM and vibrating sample magnetometry (VSM. P3TArH-coated MNPs (MNP@P3TArH showed higher capabilities for the extraction of commonly-used phthalates and were optimized for the magnetic-solid phase extraction (MSPE of environmental samples. Separation and determination of the extracted phthalates, namely dimethyl phthalate (DMP, diethyl phthalate (DEP, dipropyl phthalate (DPP, dibutyl phthalate (DBP, butyl benzyl phthalate (BBP, dicyclohexyl phthalate (DCP, di-ethylhexyl phthalate (DEHP and di-n-octyl phthalate (DNOP, were conducted by a gas chromatography-flame ionization detector (GC-FID. The best working conditions were as follows; sample at pH 7, 30 min extraction time, ethyl acetate as the elution solvent, 500-µL elution solvent volumes, 10 min desorption time, 10-mg adsorbent dosage, 20-mL sample loading volume and 15 g·L−1 concentration of NaCl. Under the optimized conditions, the analytical performances were determined with a linear range of 0.1–50 µg·L−1 and a limit of detection at 0.08–0.468 µg·L−1 for all of the analytes studied. The intra-day (n = 7 and inter-day (n = 3 relative standard deviations (RSD% of three replicates were each demonstrated in the range of 3.7–4.9 and 3.0–5.0, respectively. The steadiness and reusability studies suggested that the MNP@P3TArH could be used up to five cycles. The proposed method was executed for the analysis of real water samples, namely commercial bottled mineral water and bottled fresh milk, whereby recoveries in the range of 68%–101% and RSD% lower than 7.7 were attained.

  2. Chemiluminescence analysis for HBV-DNA hybridization detection with magnetic nanoparticles based DNA extraction from positive whole blood samples.

    Science.gov (United States)

    He, Nongyue; Wang, Fang; Ma, Chao; Li, Chuanyan; Zeng, Xin; Deng, Yan; Zhang, Liming; Li, Zhiyang

    2013-02-01

    Molecular detection of HBV has a significant impact on prognosis and therapy of the disease. In this paper, a sensitive nucleic acid detection method of HBV was established taking advantage of magnetic nanoparticles (MNPs), chemiluminescence (CL) and polymerase chain reaction (PCR). HBV-DNA was extracted from hepatitis B positive human blood samples using MNPs adsorption method and biotin was labeled on the DNA segment after base insertion of bintin-dUTP in PCR. The biotinylated DNA segment was captured by amino probe immobilized on carboxyl MNPs and was detected by the chemiluminescence system of alkaline phosphatase catalyzing 3-(2'-spiroadamantane)-4-methoxy-4-(3"-phosphoryloxy) phenyl-1, 2-dioxetane. Different concentrations of HBV-DNA were detected under the optimized experiment conditions and the relevant CL intensity were obtained, which provided a novel research or clinic diagnosis method for the quantification detection of HBV-DNA.

  3. Is it Possible to Extract Brain Metabolic Pathways Information from In Vivo H Nuclear Magnetic Resonance Spectroscopy Data?

    CERN Document Server

    de Lara, Alejandro Chinea Manrique

    2010-01-01

    In vivo H nuclear magnetic resonance (NMR) spectroscopy is an important tool for performing non-invasive quantitative assessments of brain tumour glucose metabolism. Brain tumours are considered as fast-growth tumours because of their high rate of proliferation. In addition, tumour cells exhibit profound genetic, biochemical and histological differences with respect to the original non-transformed cellular types. Therefore, there is a strong interest from the clinical investigator point of view in understanding the role of brain metabolites in normal and pathological conditions and especially on the development of early tumour detection techniques. Unfortunately, current diagnosis techniques ignore the dynamic aspects of these signals. It is largely believed that temporal variations of NMR Spectra are noisy or just simply do not carry enough information to be exploited by any reliable diagnosis procedure. Thus, current diagnosis procedures are mainly based on empirical observations extracted from single avera...

  4. Fast Extraction and Detection of 4-Methylimidazole in Soy Sauce Using Magnetic Molecularly Imprinted Polymer by HPLC.

    Science.gov (United States)

    Feng, Zufei; Lu, Yan; Zhao, Yingjuan; Ye, Helin

    2017-11-02

    On the basis of magnetic molecularly imprinted polymer (MMIP) solid-phase extraction coupled with high performance liquid chromatography, we established a new method for the determination of the 4-methylimidazole (4-MEI) in soy sauce. Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) were used to characterize the synthesized MMIPs. To evaluate the polymers, batch rebinding experiments were carried out. The binding strength and capacity were determined from the derived Freundlich isotherm (FI) equation. The selective recognition capability of MMIPs was investigated with a reference compound and a structurally similar compound. As a selective pre-concentration sorbents for 4-methylimidazole in soy sauce, the MMIPs showed a satisfied recoveries rate of spiked samples, ranged from 97% to 105%. As a result, the prepared MMIPs could be applied to selectively pre-concentrate and determine 4-methylimidazole in soy sauce samples.

  5. Efficient extraction method using magnetic carbon nanotubes to analyze cocaine and benzoylecgonine in breast milk by GC/MS.

    Science.gov (United States)

    Dos Santos, Rosimeire Resende; Nunes Paiva, Maria José; Veloso, Júlio César; Serp, Philippe; Lourdes Cardeal, Zenilda de; Menezes, Helvécio Costa

    2017-11-01

    The increasing use of cocaine (COC) during breastfeeding has led to growing concern about exposure of infants. Therefore, to study this exposure, a new method to analyze COC and benzoylecgonine in breast milk was developed. A new extraction method was used for the first time to analyze COC and its major metabolite, benzoylecgonine, in breast milk using magnetic carbon nanotubes partially doped with nitrogen. The calibration curves were linear in the range 5.0-180.0 ng ml-1. The limit of quantification was 5.0 ng ml-1. Coefficients of variation were between 3.2 and 13.9%. Recovery was between 89.6 and 99.2%. The proposed method is simple, efficient and suitable to determine analytes in breast milk.

  6. Fast Extraction and Detection of 4-Methylimidazole in Soy Sauce Using Magnetic Molecularly Imprinted Polymer by HPLC

    Directory of Open Access Journals (Sweden)

    Zufei Feng

    2017-11-01

    Full Text Available On the basis of magnetic molecularly imprinted polymer (MMIP solid-phase extraction coupled with high performance liquid chromatography, we established a new method for the determination of the 4-methylimidazole (4-MEI in soy sauce. Scanning electron microscopy (SEM, Fourier transform infrared (FT-IR, X-ray diffraction (XRD and vibrating sample magnetometer (VSM were used to characterize the synthesized MMIPs. To evaluate the polymers, batch rebinding experiments were carried out. The binding strength and capacity were determined from the derived Freundlich isotherm (FI equation. The selective recognition capability of MMIPs was investigated with a reference compound and a structurally similar compound. As a selective pre-concentration sorbents for 4-methylimidazole in soy sauce, the MMIPs showed a satisfied recoveries rate of spiked samples, ranged from 97% to 105%. As a result, the prepared MMIPs could be applied to selectively pre-concentrate and determine 4-methylimidazole in soy sauce samples.

  7. Finite volume effects for nucleon and heavy meson masses

    CERN Document Server

    Colangelo, Gilberto; Lanz, Stefan

    2010-01-01

    We apply the resummed version of the L\\"uscher formula to analyze finite volume corrections to the mass of the nucleon and of heavy mesons. We show that by applying the subthreshold expansion of the scattering amplitudes one can express the finite volume corrections in terms of only a few physical observables and the size of the box. In the case of the nucleon, the available information about the quark mass dependence of these physical quantities is discussed and used to assess the finite volume corrections to the nucleon mass as a function of the quark mass including a detailed analysis of the remaining uncertainties. For heavy mesons, the L\\"uscher formula is derived both fully relativistically and in a nonrelativistic approximation and a first attempt at a numerical analysis is made.

  8. Polarization transfer in weak pion production off the nucleon

    Science.gov (United States)

    Graczyk, Krzysztof M.; Kowal, Beata E.

    2018-01-01

    Polarization transfer (PT) observables in the single pion production induced by the charged current interaction of the neutrino with the nucleon are examined. The polarization components of the final nucleon and the charged lepton are calculated within two models for the pion production. The predictions are made for neutrino energy of the order of 1 GeV as well as for the T2K energy distribution. It is demonstrated that the PT observables, the degree of polarization and the polarization components of outgoing fermions, are sensitive to assumptions about the nonresonant background model. In particular it is shown that the normal components of the polarization of the outgoing nucleon and the lepton are determined by the interference between the resonant (RES) and nonresonant (NB) amplitudes. Moreover, the sign of the normal component of the polarization of the charged lepton is fixed by the relative sign between the RES and the NB amplitudes.

  9. Isospin Violation in Threshold Pion-Nucleon Scattering

    CERN Document Server

    Ericson, Torleif Eric Oskar

    2005-01-01

    We discuss the electromagnetic corrections to the pion-nucleon scattering lengths generated by minimal e. m. coupling from a knowledge of the low energy expansion of the pion-nucleon elastic scattering amplitude as well as from the nucleon and delta pole terms, all a consequence of purely strong interactions. We assume the heavy baryon limit; the e.m. and axial form factors and the masses are used with their empirical values, such that there is no free parameter. The different terms have a clear physical and intuitive origin. In particular, a large isospin breaking contribution to the isoscalar term appears for the elastic charged-pion scattering lengths. We attempt a comparison to the results from chiral effective field theory (EFT) with a physical interpretation of the empirical constants in that approach. The results are applied to the energy shift and width of pionic hydrogen.

  10. High Energy Break-Up of Few-Nucleon Systems

    Science.gov (United States)

    Sargsian, Misak

    2008-03-01

    We discus recent developments in theory of high energy two-body break-up reactions of few-nucleon systems. The characteristics of these reactions are such that the hard two-body quasielastic subprocess can be clearly separated from the accompanying soft subprocesses. We discuss in details the hard rescattering model (HRM) in which hard photodisintegration develops in two stages. At first, photon knocks-out an energetic quark which rescatters subsequently with a quark of the other nucleon. The latter provides a mechanism of sharing the initial high momentum of the photon by the outgoing two nucleons. Within HRM we discuss hard break-up reactions involving 2D and 3He targets. Another development of HRM is the prediction of new helicity selection mechanism for hard two-body reactions, which was apparently confirmed in the recent JLab experiment.

  11. Magnetic

    National Research Council Canada - National Science Library

    Essam Aboud; Nabil El-Masry; Atef Qaddah; Faisal Alqahtani; Mohammed R.H. Moufti

    2015-01-01

    .... A joint interpretation and inversion of gravity and magnetic data were used to estimate the thickness of the lava flows, delineate the subsurface structures of the study area, and estimate the depth...

  12. Selenium speciation in radix puerariae using ultrasonic assisted extraction combined with reversed phase high performance liquid chromatography-inductively coupled plasma-mass spectrometry after magnetic solid-phase extraction with 5-sulfosalicylic acid functionalized magnetic nanoparticles

    Science.gov (United States)

    Cao, Yupin; Yan, Lizhen; Huang, Hongli; Deng, Biyang

    2016-08-01

    A new method for determination of selenium species in radix puerariae was described. The method consists of sample enrichment with 5-sulfosalicylic acid (SSA)-functionalized silica-coated magnetic nanoparticles (SMNPs), high performance liquid chromatography (HPLC) separation, and online detection using inductively coupled plasma mass spectrometry (ICP-MS). The selenium species were extracted using ultrasonic extraction system with a mixture of protease K and lipase. The SSA-SMNPs were used to enrich trace amounts of selenite [Se(IV)], selenate [Se(VI)], selenomethionine (SeMet), and selenocystine (SeCys2) from lower selenium containing samples. Under the optimal conditions, the limits of detection (3σ) for SeCys2, Se(IV), SeMet and Se(VI) were observed as 0.0023, 0.0015, 0.0043, and 0.0016 ng mL- 1, respectively. The RSD values (n = 6) of method for intraday were observed between 0.5% and 0.9%. The RSD values of method for interday were less than 1.3%. The linear concentration ranges for SeCys2, Se(IV), SeMet and Se(VI) were 0.008-1000, 0.005-200, 0.015-500 and 0.006-200 ng mL- 1, respectively. The detection limits of this method were improved by 10 times due to the enrichment with the SSA-SMNP extraction. The contents of SeCys2, Se(IV), SeMet, and Se(VI) in radix puerariae were determined as 0.0140, 0.171, 0.0178, and 0.0344 μg g- 1, respectively. The recoveries were in the range of 95.6%-99.4% and the RSDs (n = 6) of recoveries were less than 1.5%.

  13. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      The magnet was energised at the beginning of March 2012 at a low current to check all the MSS safety chains. Then the magnet was ramped up to 3.8 T on 6 March 2012. Unfortunately two days later an unintentional switch OFF of the power converter caused a slow dump. This was due to a misunderstanding of the CCC (CERN Control Centre) concerning the procedure to apply for the CMS converter control according to the beam-mode status at that time. Following this event, the third one since 2009, a discussion was initiated to define possible improvement, not only on software and procedures in the CCC, but also to evaluate the possibility to upgrade the CMS hardware to prevent such discharge from occurring because of incorrect procedure implementations. The magnet operation itself was smooth, and no power cuts took place. As a result, the number of magnetic cycles was reduced to the minimum, with only two full magnetic cycles from 0 T to 3.8 T. Nevertheless the magnet suffered four stops of the cryogeni...

  14. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      Following the unexpected magnet stops last August due to sequences of unfortunate events on the services and cryogenics [see CMS internal report], a few more events and initiatives again disrupted the magnet operation. All the magnet parameters stayed at their nominal values during this period without any fault or alarm on the magnet control and safety systems. The magnet was stopped for the September technical stop to allow interventions in the experimental cavern on the detector services. On 1 October, to prepare the transfer of the liquid nitrogen tank on its new location, several control cables had to be removed. One cable was cut mistakenly, causing a digital input card to switch off, resulting in a cold-box (CB) stop. This tank is used for the pre-cooling of the magnet from room temperature down to 80 K, and for this reason it is controlled through the cryogenics control system. Since the connection of the CB was only allowed for a field below 2 T to avoid the risk of triggering a fast d...

  15. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    Operation of the magnet has gone quite smoothly during the first half of this year. The magnet has been at 4.5K for the full period since January. There was an unplanned short stop due to the CERN-wide power outage on May 28th, which caused a slow dump of the magnet. Since this occurred just before a planned technical stop of the LHC, during which access in the experimental cavern was authorized, it was decided to leave the magnet OFF until 2nd June, when magnet was ramped up again to 3.8T. The magnet system experienced a fault also resulting in a slow dump on April 14th. This was triggered by a thermostat on a filter choke in the 20kA DC power converter. The threshold of this thermostat is 65°C. However, no variation in the water-cooling flow rate or temperature was observed. Vibration may have been the root cause of the fault. All the thermostats have been checked, together with the cables, connectors and the read out card. The tightening of the inductance fixations has also been checked. More tem...

  16. A nucleon-pair and boson coexistent description of nuclei

    Science.gov (United States)

    Dai, Lianrong; Pan, Feng; Draayer, J. P.

    2017-07-01

    We study a mixture of s-bosons and like-nucleon pairs with the standard pairing interaction outside an inert core. Competition between the nucleon-pairs and s-bosons is investigated in this scenario. The robustness of the BCS-BEC coexistence and crossover phenomena are examined through an analysis of pf-shell nuclei with realistic single-particle energies, in which two configurations with Pauli blocking of nucleon-pair orbits due to the formation of the s-bosons is taken into account. When the nucleon-pair orbits are considered to be independent of the s-bosons, the BCS-BEC crossover becomes smooth, with the number of the s-bosons noticeably more than that of the nucleon-pairs near the half-shell point, a feature that is demonstrated in the pf-shell for several values of the standard pairing interaction strength. As a further test of the robustness of the BCS-BEC coexistence and crossover phenomena in nuclei, results are given for values of even-even 102-130Sn with 100Sn taken as a core and valence neutron pairs confined within the 1d 5/2, 0g 7/2, 1d 3/2, 2s 1/2, 1h 11/2 orbits in the nucleon-pair orbit and the s-boson independent approximation. The results indicate that the B(E2) values are reproduced well. Supported by National Natural Science Foundation of China (11375080, 11675071), the U.S. National Science Foundation (OCI-0904874 and ACI-1516338), U. S. Department of Energy (DE-SC0005248), the Southeastern Universities Research Association, the China-U. S. Theory Institute for Physics with Exotic Nuclei (CUSTIPEN) (DE-SC0009971), and the LSU-LNNU joint research program (9961) is acknowledged

  17. A novel dianionic amino acid ionic liquid-coated PEG 4000 modified Fe3O4 nanocomposite for the magnetic solid-phase extraction of trypsin.

    Science.gov (United States)

    Yang, Qin; Wang, Yuzhi; Zhang, Hongmei; Xu, Kaijia; Wei, Xiaoxiao; Xu, Panli; Zhou, Yigang

    2017-11-01

    A novel magnetic extractant, PEG 4000 modified Fe3O4nanomaterial that coated with dianionic amino acid ionic liquid (Fe3O4@PEG@DAAAIL), was successfully synthesized and characterized. X-ray diffraction (XRD), transmission electron microscope (TEM), vibrating sample magnetometer (VSM), fourier transform infrared spectrometry (FT-IR), thermal gravimetric analysis (TGA) and zeta potentials were used to confirm that the novel nanocomposite was successfully synthesized. Subsequently, the prepared Fe3O4@PEG@DAAAIL nanocomposite was used as the extractant for trypsin coupled with magnetic solid-phase extraction (MSPE). The concentrations of trypsin in the supernatant were detected by UV-vis spectrophotometer at 278nm. The extraction ability turned out to be better than the other four kinds of extractants prepared in this work. Furthermore, the influence of a series of factors, such as extraction time and temperature, initial trypsin concentration, the value of pH and ionic strength, was systematically investigated. Under the optimal extraction condition, the extraction capacity for trypsin could reach up to 718.73mg/g, absolutely higher than that of other adsorbents reported. This satisfactory extraction capacity could be maintained unchangeable after at least eight days, and kept over 90% of initial extraction capacity after eight recycles. What's more, the activity of trypsin after extraction retained 92.29% of initial activity, verifying the biocompatibility of the prepared extractant. Finally, the developed Fe3O4@PEG@DAAAIL-MSPE method was successfully applied to the real sample analysis with satisfactory results. All of above proves the potential value of Fe3O4@PEG@DAAAIL-MSPE in the analysis of biomass. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Study of the Hyperon-Nucleon Interaction in Exclusive Λ Photoproduction off the Deuteron

    Directory of Open Access Journals (Sweden)

    Zachariou Nicholas

    2016-01-01

    Full Text Available The study of final-state interactions in exclusive hyperon photoproduction off the deuteron is a promising approach to extract information about the hyperon-nucleon (YN interaction. First preliminary results on the azimuthal asymmetry ∑, as well as the polarization transfer coeffcients Ox, Oz, Cx, and Cz for the reaction γd → K+ Λn initiated with linearly and circularly polarized photon beam are presented. The data were taken with the CLAS detector in Hall B of Jefferson Lab during the E06-103 experiment. The large kinematic coverage of the CLAS, combined with the exceptionally high quality of the experimental data, allows identifying and selecting final-state interaction events to extract single- and double-polarization observables and their kinematical dependencies.

  19. Study of the Hyperon-Nucleon Interaction in Exclusive Λ Photoproduction off the Deuteron

    Energy Technology Data Exchange (ETDEWEB)

    Zachariou, Nicholas [Univ. of Edinburgh, Scotland (United Kingdom); Ilieva, Yordanka [Univ. of South Carolina, Columbia, SC (United States); Cao, Tongtong [Univ. of South Carolina, Columbia, SC (United States)

    2016-03-01

    The study of final-state interactions in exclusive hyperon photoproduction off the deuteron is a promising approach to extract information about the hyperon-nucleon (YN) interaction. First preliminary results on the azimuthal asymmetry ∑, as well as the polarization transfer coeffcients Ox, Oz, Cx, and Cz for the reaction γd → K+ Λn initiated with linearly and circularly polarized photon beam are presented. The data were taken with the CLAS detector in Hall B of Jefferson Lab during the E06-103 experiment. The large kinematic coverage of the CLAS, combined with the exceptionally high quality of the experimental data, allows identifying and selecting final-state interaction events to extract single- and double-polarization observables and their kinematical dependencies.

  20. Quantification of mycotoxins in vegetable oil by UPLC-MS/MS after magnetic solid-phase extraction.

    Science.gov (United States)

    Zhao, Yan; Wan, Li-Hong; Bai, Xiao-Lin; Liu, Yi-Ming; Zhang, Feng-Ping; Liu, Yao-Min; Liao, Xun

    2017-07-01

    The detection of mycotoxin contamination in foodstuffs is highly significant for public health. Herein we report an analytical method based on magnetic solid-phase extraction (MSPE) and UPLC-MS/MS for the simultaneous determination of mycotoxins, including fumonisins B1 (FB1), zearalenone (ZON) and ochratoxin A (OTA), in vegetable oil. Magnetic nanoparticles coated with double layers of silicon dioxide were synthesised and found to be an effective MSPE adsorbent for mycotoxins. The proposed MSPE procedure serves not only for sample clean-up but also for mycotoxin enrichment that enhances greatly the assay's sensitivity. Under the selected MSPE conditions, linear matrix-matched calibration curves were obtained for mycotoxins in a concentration range from 0.178 to 625 μg kg-1. The limits of detection were 0.210 μg kg-1 for FB1, 0.0800 μg kg-1 for OTA and 1.03 μg kg-1 for ZON. The proposed MSPE UPLC-MS/MS method was applied for the determination of mycotoxins in vegetable oil samples, including maize oil, rapeseed oil and soybean oil. ZON was detected in a maize oil at 101 μg kg-1, which is below the European Union limit of 200 μg kg-1 in foodstuffs.

  1. Phosphopeptide enrichment: Development of magnetic solid phase extraction method based on polydopamine coating and Ti(4+)-IMAC.

    Science.gov (United States)

    Piovesana, Susy; Capriotti, Anna Laura; Cavaliere, Chiara; Ferraris, Francesca; Samperi, Roberto; Ventura, Salvatore; Laganà, Aldo

    2016-02-25

    Protein post translational modifications currently represent one of the main challenges with proteomic analysis, due to the important biological role they play within cells. Protein phosphorylation is one of the most important, with several approaches developed for phosphopeptides enrichment and analysis, essential for comprehensive phosphoproteomic analysis. However, the development of new materials for phosphopeptides enrichment may overcome previous drawbacks and improve enrichment of such peptides. In this regard, new magnetic stationary phases based on polydopamine coating and Ti(4+) immobilization exploit the potential of IMAC enrichment and couple it with the versatility of magnetic solid phase extraction. In this work the use of such stationary phase was extended from the MALDI proof of concept stage with the development of an optimized method for phosphopeptides enrichment compatible with typical shotgun proteomics experimental workflows. Different loading and elution buffers were tested to improve phosphopeptides recovery and enrichment selectivity. Finally, the analysis of isolated peptides pointed out that polydopamine alone is an ideal support matrix for polar post translational modifications because it enables to reduce unspecific binding and preferentially binds hydrophilic peptides. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. +Facile extraction of azide in sartan drugs using magnetized anion-exchange metal-organic frameworks prior to ion chromatography.

    Science.gov (United States)

    Zhang, Sainan; Han, Peipei; Xia, Yan

    2017-09-08

    Quaternary amine functionalized metal-organic framework MIL-101(Cr) (MIL-101(Cr)-NMe3) was prepared as the sorbent for the magnetic solid-phase extraction (MSPE) of azide from sartan drugs before ion chromatography determination. Magnetization of MIL-101-NMe3 were achieved concurrently by adding MIL-101-NMe3 and Fe3O4@SiO2 to the sample solution under ultrasonication. The prepared Fe3O4@SiO2/MIL-101-NMe3 gave the adsorption capacity of 37.5mgg-1. The developed method had a detection limit of 0.24μgL-1 and quantitation limit of 0.79μgL-1 for azide. The relative standard deviations for the intra-day retention time and peak area were 0.52% and 0.36% (n=5), respectively. The developed method was successfully applied for the determination of azide in sartan drugs with the recoveries from 96.5% to 100.5%. Copyright © 2017. Published by Elsevier B.V.

  3. Surfactant-enhanced spectrofluorimetric determination of total aflatoxins from wheat samples after magnetic solid-phase extraction using modified Fe3O4 nanoparticles

    Science.gov (United States)

    Manafi, Mohammad Hanif; Allahyari, Mehdi; Pourghazi, Kamyar; Amoli-Diva, Mitra; Taherimaslak, Zohreh

    2015-07-01

    The extraction and preconcentration of total aflatoxins (including aflatoxin B1, B2, G1, and G2) using magnetic nanoparticles based solid phase extraction (MSPE) followed by surfactant-enhanced spectrofluorimetric detection was proposed. Ethylene glycol bis-mercaptoacetate modified silica coated Fe3O4 nanoparticles as an efficient antibody-free adsorbent was successfully applied to extract aflatoxins from wheat samples. High surface area and strong magnetization properties of magnetic nanoparticles were utilized to achieve high enrichment factor (97), and satisfactory recoveries (92-105%) using only 100 mg of the adsorbent. Furthermore, the fast separation time (less than 10 min) avoids many time-consuming cartridge loading or column-passing procedures accompany with the conventional SPE. In determination step, signal enhancement was performed by formation of Triton X-100 micelles around the analytes in 15% (v/v) acetonitrile-water which dramatically increase the sensitivity of the method. Main factors affecting the extraction efficiency and signal enhancement of the analytes including pH of sample solution, desorption conditions, extraction time, sample volume, adsorbent amount, surfactant concentration and volume and time of micelle formation were evaluated and optimized. Under the optimum conditions, wide linear range of 0.1-50 ng mL-1 with low detection limit of 0.03 ng mL-1 were obtained. The developed method was successfully applied to the extraction and preconcentration of aflatoxins in three commercially available wheat samples and the results were compared with the official AOAC method.

  4. Submicrometric Magnetic Nanoporous Carbons Derived from Metal-Organic Frameworks Enabling Automated Electromagnet-Assisted Online Solid-Phase Extraction.

    Science.gov (United States)

    Frizzarin, Rejane M; Palomino Cabello, Carlos; Bauzà, Maria Del Mar; Portugal, Lindomar A; Maya, Fernando; Cerdà, Víctor; Estela, José M; Turnes Palomino, Gemma

    2016-07-19

    We present the first application of submicrometric magnetic nanoporous carbons (μMNPCs) as sorbents for automated solid-phase extraction (SPE). Small zeolitic imidazolate framework-67 crystals are obtained at room temperature and directly carbonized under an inert atmosphere to obtain submicrometric nanoporous carbons containing magnetic cobalt nanoparticles. The μMNPCs have a high contact area, high stability, and their preparation is simple and cost-effective. The prepared μMNPCs are exploited as sorbents in a microcolumn format in a sequential injection analysis (SIA) system with online spectrophotometric detection, which includes a specially designed three-dimensional (3D)-printed holder containing an automatically actuated electromagnet. The combined action of permanent magnets and an automatically actuated electromagnet enabled the movement of the solid bed of particles inside the microcolumn, preventing their aggregation, increasing the versatility of the system, and increasing the preconcentration efficiency. The method was optimized using a full factorial design and Doehlert Matrix. The developed system was applied to the determination of anionic surfactants, exploiting the retention of the ion-pairs formed with Methylene Blue on the μMNPC. Using sodium dodecyl sulfate as a model analyte, quantification was linear from 50 to 1000 μg L(-1), and the detection limit was equal to 17.5 μg L(-1), the coefficient of variation (n = 8; 100 μg L(-1)) was 2.7%, and the analysis throughput was 13 h(-1). The developed approach was applied to the determination of anionic surfactants in water samples (natural water, groundwater, and wastewater), yielding recoveries of 93% to 110% (95% confidence level).

  5. Nucleon form factors in dispersively improved chiral effective field theory: Scalar form factor

    Science.gov (United States)

    Alarcón, J. M.; Weiss, C.

    2017-11-01

    We propose a method for calculating the nucleon form factors (FFs) of G -parity-even operators by combining chiral effective field theory (χ EFT ) and dispersion analysis. The FFs are expressed as dispersive integrals over the two-pion cut at t >4 Mπ2 . The spectral functions are obtained from the elastic unitarity condition and expressed as products of the complex π π →N N ¯ partial-wave amplitudes and the timelike pion FF. χ EFT is used to calculate the ratio of the partial-wave amplitudes and the pion FF, which is real and free of π π rescattering in the t channel (N /D method). The rescattering effects are then incorporated by multiplying with the squared modulus of the empirical pion FF. The procedure results in a marked improvement compared to conventional χ EFT calculations of the spectral functions. We apply the method to the nucleon scalar FF and compute the scalar spectral function, the scalar radius, the t -dependent FF, and the Cheng-Dashen discrepancy. Higher-order chiral corrections are estimated through the π N low-energy constants. Results are in excellent agreement with dispersion-theoretical calculations. We elaborate several other interesting aspects of our method. The results show proper scaling behavior in the large-Nc limit of QCD because the χ EFT calculation includes N and Δ intermediate states. The squared modulus of the timelike pion FF required by our method can be extracted from lattice QCD calculations of vacuum correlation functions of the operator at large Euclidean distances. Our method can be applied to the nucleon FFs of other operators of interest, such as the isovector-vector current, the energy-momentum tensor, and twist-2 QCD operators (moments of generalized parton distributions).

  6. An easy, convenient cell and tissue extraction protocol for nuclear magnetic resonance metabolomics.

    Science.gov (United States)

    Matheus, Nicolas; Hansen, Sylvain; Rozet, Eric; Peixoto, Paul; Maquoi, Erik; Lambert, Vincent; Noël, Agnès; Frédérich, Michel; Mottet, Denis; de Tullio, Pascal

    2014-01-01

    As a complement to the classic metabolomics biofluid studies, the visualisation of the metabolites contained in cells or tissues could be a very powerful tool to understand how the local metabolism and biochemical pathways could be affected by external or internal stimuli or pathologies. Therefore, extraction and/or lysis is necessary to obtain samples adapted for use with the current analytical tools (liquid NMR and MS). These extraction or lysis work-ups are often the most labour-intensive and rate-limiting steps in metabolomics, as they require accuracy and repeatability as well as robustness. Many of the procedures described in the literature appear to be very time-consuming and not easily amenable to automation. To find a fast, simplified procedure that allows release of the metabolites from cells and tissues in a way that is compatible with NMR analysis. We assessed the use of sonication to disrupt cell membranes or tissue structures. Both a vibrating probe and an automated bath sonicator were explored. The application of sonication as the disruption procedure led to reproducible NMR spectral data compatible with metabolomics studies. This method requires only a small biological tissue or cell sample, and a rapid, reduced work-up was applied before analysis. The spectral patterns obtained are comparable with previous, well-described extraction protocols. The rapidity and the simplicity of this approach could represent a suitable alternative to the other protocols. Additionally, this approach could be favourable for high- throughput applications in intracellular and intratissular metabolite measurements. Copyright © 2014 John Wiley & Sons, Ltd.

  7. Excited-Nucleon Spectroscopy with 2+1 Fermion Flavors

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Saul; Foley, Justin; Morningstar, Colin; Wong, Ricky; Edwards, Robert G; Joo, Balint; Richards, David G; Juge, Jimmy; Lin, Huey-Lin; Mathur, Nilmani; Peardon, Micheal J

    2010-01-01

    We present progress made by the Hadron Spectrum Collaboration (HSC) in determining the tower of excited nucleon states using 2+1-flavor anisotropic clover lattices. The HSC has been investigating interpolating operators projected into irreducible representations of the cubic group in order to better calculate two-point correlators for nucleon spectroscopy; results are published for quenched and 2-flavor anisotropic Wilson lattices. In this work, we present the latest results using a new technique, distillation, which allows us to reach higher statistics than before. Future directions will be outlined at the end.

  8. Doubly-polarised pion photoproduction on the nucleon at MAMI

    Directory of Open Access Journals (Sweden)

    Costanza Susanna

    2017-01-01

    These new, high-quality doubly-polarised pion-photoproduction data sets provide a valuable input to the study of the nucleon structure and excitation spectrum by significantly constraining the electromagnetic multipole evaluation performed by the different available partial wave analysis models. Furthermore, the helicity dependent observables provide the main ingredient for the verification of the well-known Gerasimov-Drell-Hearn (GDH sum rule, which relates the helicity-dependent photoasborption process to the main static nucleon properties (mass, charge, spin.

  9. Use of the Husimi distribution for nucleon tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, Yoshikazu [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Hatta, Yoshitaka, E-mail: hatta@yukawa.kyoto-u.ac.jp [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)

    2015-08-15

    In the context of nucleon structure, the Wigner distribution has been commonly used to visualize the phase-space distribution of quarks and gluons inside the nucleon. However, the Wigner distribution does not allow for a probabilistic interpretation because it takes negative values. In pursuit of a positive phase-space distribution in QCD, we introduce the Husimi distribution and demonstrate its advantages via a simple one-loop example. We also comment on a possible connection to the semiclassical approach to saturation physics at small-x.

  10. In situ reactive extraction of cottonseeds with methyl acetate for biodiesel production using magnetic solid acid catalysts.

    Science.gov (United States)

    Wu, Haitang; Liu, Yanping; Zhang, Junhua; Li, Guanglu

    2014-12-01

    A magnetic solid acid catalyst S2O8(2)(-)/ZrO2-TiO2-Fe3O4 was prepared by coprecipitation and impregnation methods and its catalytic activity was investigated for the reactive extraction of cottonseeds with methyl acetate to produce biodiesel. The physicochemical properties of the catalyst were characterized in detail. The influences of Zr/Ti molar ratio and calcination temperature on the catalytic performance were investigated. Moreover, optimization of the reactive extraction process was performed using response surface methodology coupled with central composite design. The catalyst with a Zr/Ti molar ratio of 3/1 calcined at 550°C showed the best activity. An optimum biodiesel yield of 98.5% was obtained under the reaction temperature of 50°C, catalyst amount of 21.3wt.%, methyl acetate/seed ratio of 13.8ml/g and 10.8h of reaction time. Reuse of this catalyst indicated that it had steady catalytic activity and high recovery rate which could be a promising catalyst for biodiesel production from oilseeds. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Magnetic field assisted μ-solid phase extraction of anti-inflammatory and loop diuretic drugs by modified polybutylene terephthalate nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Bagheri, Habib, E-mail: bagheri@sharif.edu; Khanipour, Peyman; Asgari, Sara

    2016-08-31

    A magnetic nanocomposite consisting of nanoparticles–polybutylene terephthalate (MNPs–PBT) was electrospun and used as an extracting medium for an on-line μ-solid phase extraction (μ–SPE)–high performance liquid chromatography (HPLC) set–up with an ultraviolet (UV) detection system. Due to the magnetic property of the prepared nanofibers, the whole extraction procedure was implemented under an external magnetic field to enhance the extraction efficiencies. The developed method along with the synthesized nanocomposite were found to be appropriate for the determination of trace levels of selected drugs including furosemide, naproxen, diclofenac and clobetasol propionate in the urine sample. The prepared MNPs-PBT electrospun nanocomposite was characterized using the scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and Fourier transform infrared (FT–IR) spectroscopy. The prepared magnetic fibers showed high porosity, which was another driving force for the extraction efficiency enhancement. Major parameters affecting the extraction efficiency of the selected drugs were optimized. The limits of detections (LOD) of the studied drugs were in the range of 0.4–1.6 μg L{sup −1} and the limits of quantification (LOQ) were 1–4 μg L{sup −1} under the optimized conditions. Relative standard deviation (RSD%) for three replicates at three concentration levels of 6, 100 and 400 μg L{sup −1} were 5.9–8.0% while acceptable linear range with two orders of magnitude was obtained (R{sup 2} = 0.99). The method was validated by the determination of the selected drugs in urine samples and the results indicated that this method has sufficient potential for enrichment and determination of the desired drugs in the urine sample. The relative recovery values were found to be in the range of 78–91%. Implementing the developed on–line μ–SPE method under the external magnetic field induction, led to higher extraction efficiencies

  12. A novel magnetic poly(aniline-naphthylamine)-based nanocomposite for micro solid phase extraction of rhodamine B.

    Science.gov (United States)

    Bagheri, Habib; Daliri, Rasoul; Roostaie, Ali

    2013-09-10

    A novel Fe3O4-poly(aniline-naphthylamine)-based nanocomposite was synthesized by chemical oxidative polymerization process as a magnetic sorbent for micro solid phase extraction. The scanning electron microscopy images of the synthesized nanocomposite revealed that the copolymer posses a porous structure with diameters less than 50nm. The extraction efficiency of this sorbent was examined by isolation of rhodamine B, a mutagenic and carcinogenic dye, from aquatic media in dispersion mode. Among different synthesized polymers, Fe3O4/poly(aniline-naphthylamine) nanocomposite showed a prominent efficiency. Parameters including the desorption solvent, amount of sorbent, desorption time, sample pH, ionic strength, extraction time and stirring rate were optimized. Under the optimum condition, a linear spiked calibration curve in the range of 0.35-5.00μgL(-1) with R(2)=0.9991 was obtained. The limits of detection (3Sb) and limits of quantification (10Sb) of the method were 0.10μgL(-1) and 0.35μgL(-1) (n=3), respectively. The relative standard deviation for water sample with 0.5μgL(-1) of RhB was 4.2% (n=5) and the absolute recovery was 92%. The method was applied for the determination of rhodamine B in dishwashing foam, dishwashing liquid, shampoo, pencil, matches tips and eye shadows samples and the relative recovery percentage were in the range of 94-99%. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. A novel magnetic poly(aniline-naphthylamine)-based nanocomposite for micro solid phase extraction of rhodamine B

    Energy Technology Data Exchange (ETDEWEB)

    Bagheri, Habib, E-mail: bagheri@sharif.edu; Daliri, Rasoul; Roostaie, Ali

    2013-09-10

    Graphical abstract: -- Highlights: •A Fe{sub 3}O{sub 4}–aniline-naphthylamine nanocomposite was prepared via a simple route. •The magnetic nanocomposite was applied for isolation of RhB from water. •The nanocomposite applicability was compared with other pristine polymers. •The method was applied for the determination of RhB in different samples. -- Abstract: A novel Fe{sub 3}O{sub 4}–poly(aniline-naphthylamine)-based nanocomposite was synthesized by chemical oxidative polymerization process as a magnetic sorbent for micro solid phase extraction. The scanning electron microscopy images of the synthesized nanocomposite revealed that the copolymer posses a porous structure with diameters less than 50 nm. The extraction efficiency of this sorbent was examined by isolation of rhodamine B, a mutagenic and carcinogenic dye, from aquatic media in dispersion mode. Among different synthesized polymers, Fe{sub 3}O{sub 4}/poly(aniline-naphthylamine) nanocomposite showed a prominent efficiency. Parameters including the desorption solvent, amount of sorbent, desorption time, sample pH, ionic strength, extraction time and stirring rate were optimized. Under the optimum condition, a linear spiked calibration curve in the range of 0.35–5.00 μg L{sup −1} with R{sup 2} = 0.9991 was obtained. The limits of detection (3S{sub b}) and limits of quantification (10S{sub b}) of the method were 0.10 μg L{sup −1} and 0.35 μg L{sup −1} (n = 3), respectively. The relative standard deviation for water sample with 0.5 μg L{sup −1} of RhB was 4.2% (n = 5) and the absolute recovery was 92%. The method was applied for the determination of rhodamine B in dishwashing foam, dishwashing liquid, shampoo, pencil, matches tips and eye shadows samples and the relative recovery percentage were in the range of 94–99%.

  14. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      The magnet and its sub-systems were stopped at the beginning of the winter shutdown on 8th December 2011. The magnet was left without cooling during the cryogenics maintenance until 17th January 2012, when the cryoplant operation resumed. The magnet temperature reached 93 K. The vacuum pumping was maintained during this period. During this shutdown, the yearly maintenance was performed on the cryogenics, the vacuum pumps, the magnet control and safety systems, and the power converter and discharge lines. Several preventive actions led to the replacement of the electrovalve command coils, and the 20A DC power supplies of the magnet control system. The filters were cleaned on the demineralised water circuits. The oil of the diffusion pumps was changed. On the cryogenics, warm nitrogen at 343 K was circulated in the cold box to regenerate the filters and the heat exchangers. The coalescing filters have been replaced at the inlet of both the turbines and the lubricant trapping unit. The active cha...

  15. MAGNET

    CERN Multimedia

    B. Curé

    2011-01-01

    The CMS magnet has been running steadily and smoothly since the summer, with no detected flaw. The magnet instrumentation is entirely operational and all the parameters are at their nominal values. Three power cuts on the electrical network affected the magnet run in the past five months, with no impact on the data-taking as the accelerator was also affected at the same time. On 22nd June, a thunderstorm caused a power glitch on the service electrical network. The primary water cooling at Point 5 was stopped. Despite a quick restart of the water cooling, the inlet temperature of the demineralised water on the busbar cooling circuit increased by 5 °C, up to 23.3 °C. It was kept below the threshold of 27 °C by switching off other cooling circuits to avoid the trigger of a slow dump of the magnet. The cold box of the cryogenics also stopped. Part of the spare liquid helium volume was used to maintain the cooling of the magnet at 4.5 K. The operators of the cryogenics quickly restarted ...

  16. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    The magnet was successfully operated at the end of the year 2009 despite some technical problems on the cryogenics. The magnet was ramped up to 3.8 T at the end of November until December 16th when the shutdown started. The magnet operation met a few unexpected stops. The field was reduced to 3.5 T for about 5 hours on December 3rd due to a faulty pressure sensor on the helium compressor. The following day the CERN CCC stopped unintentionally the power converters of the LHC and the experiments, triggering a ramp down that was stopped at 2.7 T. The magnet was back at 3.8 T about 6 hours after CCC sent the CERN-wide command. Three days later, a slow dump was triggered due to a stop of the pump feeding the power converter water-cooling circuit, during an intervention on the water-cooling plant done after several disturbances on the electrical distribution network. The magnet was back at 3.8 T in the evening the same day. On December 10th a break occurred in one turbine of the cold box producing the liquid ...

  17. MAGNET

    CERN Multimedia

    B. Curé

    2013-01-01

      The magnet was operated without any problem until the end of the LHC run in February 2013, apart from a CERN-wide power glitch on 10 January 2013 that affected the CMS refrigerator, causing a ramp down to 2 T in order to reconnect the coldbox. Another CERN-wide power glitch on 15 January 2013 didn’t affect the magnet subsystems, the cryoplant or the power converter. At the end of the magnet run, the reconnection of the coldbox at 2.5 T was tested. The process will be updated, in particular the parameters of some PID valve controllers. The helium flow of the current leads was reduced but only for a few seconds. The exercise will be repeated with the revised parameters to validate the automatic reconnection process of the coldbox. During LS1, the water-cooling services will be reduced and many interventions are planned on the electrical services. Therefore, the magnet cryogenics and subsystems will be stopped for several months, and the magnet cannot be kept cold. In order to avoid unc...

  18. Polyaniline-coated chitosan-functionalized magnetic nanoparticles: Preparation for the extraction and analysis of endocrine-disrupting phenols in environmental water and juice samples.

    Science.gov (United States)

    Jiang, Xilan; Cheng, Jing; Zhou, Hongbin; Li, Feng; Wu, Wenlin; Ding, Kerong

    2015-08-15

    In the present study, chitosan (CHI) functionalized Fe3O4 magnetic microspheres coated with polyaniline (PANI) were synthesized for the first time. The chitosan-functionalized magnetic microspheres (Fe3O4@CHI) were synthesized by a co-precipitation method, and then aniline was polymerized on the magnetic core. The obtained Fe3O4@CHI@PANI microspheres were spherical core-shell structure with uniform size at about 100nm with 20-30nm diameter core. The microspheres had a high saturation magnetization of 32emu g(-)(1), which was sufficient for magnetic separation. The obtained Fe3O4@CHI@PANI magnetic microspheres were applied as magnetic adsorbents for the extraction of aromatic compounds via π-π interaction between polyaniline shell and aromatic compounds. Three endocrine-disrupting phenols, including bisphenol A (BPA), 2, 4-dichlorophenol (2, 4-DCP), and triclosan (TCS) were selected as the model analytes to verify the extraction ability of Fe3O4@CHI@PANI. The hydrophilic chitosan-functionalized Fe3O4 core (Fe3O4@CHI) improved the dispersibility of Fe3O4@CHI@PANI microspheres, and then improve its extraction efficiency. The dominant parameters affecting enrichment efficiency were investigated and optimized. Under optimal condition, the proposed method was evaluated, and applied to the analysis of phenols in real water and juice samples. The results demonstrated the method based on Fe3O4@CHI@PANI magnetic microspheres had good linearity (R(2)>0.996), and limits of detection (0.10-0.13ng mL(-1)), high repeatability (RSDrecovery (85.0-106.7%). Copyright © 2015 Elsevier B.V. All rights reserved.

  19. A Rapid Magnetic Solid Phase Extraction Method Followed by Liquid Chromatography-Tandem Mass Spectrometry Analysis for the Determination of Mycotoxins in Cereals

    Directory of Open Access Journals (Sweden)

    Giorgia La Barbera

    2017-04-01

    Full Text Available Mycotoxins can contaminate various food commodities, including cereals. Moreover, mycotoxins of different classes can co-contaminate food, increasing human health risk. Several analytical methods have been published in the literature dealing with mycotoxins determination in cereals. Nevertheless, in the present work, the aim was to propose an easy and effective system for the extraction of six of the main mycotoxins from corn meal and durum wheat flour, i.e., the main four aflatoxins, ochratoxin A, and the mycoestrogen zearalenone. The developed method exploited magnetic solid phase extraction (SPE, a technique that is attracting an increasing interest as an alternative to classical SPE. Therefore, the use of magnetic graphitized carbon black as a suitable extracting material was tested. The same magnetic material proved to be effective in the extraction of mycoestrogens from milk, but has never been applied to complex matrices as cereals. Ultra high–performance liquid chromatography tandem mass spectrometry was used for detection. Recoveries were >60% in both cereals, even if the matrix effects were not negligible. The limits of quantification of the method results were comparable to those obtained by other two magnetic SPE-based methods applied to cereals, which were limited to one or two mycotoxins, whereas in this work the investigated mycotoxins belonged to three different chemical classes.

  20. Strange quarks in the nucleon and parity violation in polarized electron scattering

    CERN Document Server

    Van de Wiele, J

    2001-01-01

    In this review, we show that the measurement of asymmetry in polarized electron- nucleon scattering provides information about the quark structure of the nucleon.. The formalism of parity-violating electron-nucleon scattering with the theoretical assumptions is presented. An experimental overview of specific experiments with recent results as well as upcoming experiments is discussed.

  1. Application of an activated carbon-based support for magnetic solid phase extraction followed by spectrophotometric determination of tartrazine in commercial beverages.

    Science.gov (United States)

    Rodríguez, José A; Escamilla-Lara, Karen A; Guevara-Lara, Alfredo; Miranda, Jose M; Páez-Hernández, Ma Elena

    2015-01-01

    A method is presented for magnetic solid phase extraction of tartrazine from nonalcoholic beverages. The method involves the extraction and clean-up by activated carbon covered with magnetite dispersed in the sample, followed by the magnetic isolation and desorption of the analyte by basified methanol. The tartrazine eluted from the magnetic support was determined by spectrophotometry. Under optimal conditions, the linear range of the calibration curve ranges from 3 to 30 mg L(-1), with a limit of detection of 1 mg L(-1). The method was validated by comparing the results with those obtained by HPLC. A precision of <5.0% was obtained in all cases and no significant differences were observed (P < 0.05).

  2. Application of an Activated Carbon-Based Support for Magnetic Solid Phase Extraction Followed by Spectrophotometric Determination of Tartrazine in Commercial Beverages

    Directory of Open Access Journals (Sweden)

    José A. Rodríguez

    2015-01-01

    Full Text Available A method is presented for magnetic solid phase extraction of tartrazine from nonalcoholic beverages. The method involves the extraction and clean-up by activated carbon covered with magnetite dispersed in the sample, followed by the magnetic isolation and desorption of the analyte by basified methanol. The tartrazine eluted from the magnetic support was determined by spectrophotometry. Under optimal conditions, the linear range of the calibration curve ranges from 3 to 30 mg L−1, with a limit of detection of 1 mg L−1. The method was validated by comparing the results with those obtained by HPLC. A precision of <5.0% was obtained in all cases and no significant differences were observed (P<0.05.

  3. On the nucleon–nucleon scattering phase shifts through ...

    Indian Academy of Sciences (India)

    By exploiting the supersymmetry-inspired factorization method through a judicious use of deuteron ground state wave function, higher partial wave nucleon–nucleon potentials, both energy independent and energy dependent, are generated. We adopt the phase function method to deal with the scattering phase shifts and ...

  4. Photoproduction ofeta-pi pairs off nucleons and deuterons

    CERN Document Server

    Kaeser, A; Ahrens, J; Annand, J R M; Arends, H J; Bantawa, K; Bartolome, P A; Beck, R; Braghieri, A; Briscoe, W J; Cherepnya, S; Costanza, S; Dieterle, M; Downie, E J; Drexler, P; Fil'kov, L V; Fix, A; Garni, S; Glazier, D I; Hamilton, D; Hornidge, D; Howdle, D; Huber, G M; Jaegle, I; Jude, T C; Kashevarov, V L; Keshelashvili, I; Kondratiev, R; Korolija, M; Krusche, B; Lisin, V; Livingston, K; MacGregor, I J D; Maghrbi, Y; Mancell, J; Manley, D M; Marinides, Z; McGeorge, J C; McNicoll, E; Mekterovic, D; Metag, V; Micanovic, S; Middleton, D G; Mushkarenkov, A; Nikolaev, A; Novotny, R; Oberle, M; Ostrick, M; Otte, P; Oussena, B; Pedroni, P; Pheron, F; Polonski, A; Prakhov, S; Robinson, J; Rostomyan, T; Schumann, S; Sikora, M H; Sober, D; Starostin, A; Strub, Th; Supek, I; Thiel, M; Thomas, A; Unverzagt, M; Walford, N K; Watts, D P; Werthmueller, D; Witthauer, L

    2016-01-01

    Quasi-free photoproduction of $\\pi\\eta$-pairs has been investigated from threshold up to incident photon energies of 1.4 GeV, respectively up to photon-nucleon invariant masses up to 1.9 GeV. Total cross sections, angular distributions, invariant-mass distributions of the $\\pi\\eta$ and meson-nucleon pairs, and beam-helicity asymmetries have been measured for the reactions $\\gamma p\\rightarrow p\\pi^0\\eta$, $\\gamma n\\rightarrow n\\pi^0\\eta$, $\\gamma p\\rightarrow n\\pi^+\\eta$, and $\\gamma n\\rightarrow p\\pi^-\\eta$ from nucleons bound inside the deuteron. For the $\\gamma p$ initial state data for free protons have also been analyzed. Finally, the total cross sections for quasi-free production of $\\pi^0\\eta$ pairs from nucleons bound in $^3$He nuclei have been investigated in view of final state interaction (FSI) effects. The experiments were performed at the tagged photon beam facility of the Mainz MAMI accelerator using an almost $4\\pi$ covering electromagnetic calorimeter composed of the Crystal Ball and TAPS dete...

  5. Introduction to Nucleonics: A Laboratory Course. Teacher's Guide.

    Science.gov (United States)

    Phelps, William; And Others

    This collection of laboratory lessons is designed primarily for the non-college bound high school student. It can be adapted, however, to a wide range of abilities. It begins with an examination of the properties of nuclear radiation, develops an understanding of the fundamentals of nucleonics, and ends with an investigation of careers in areas…

  6. A relativistic quark–diquark model for the nucleon

    Indian Academy of Sciences (India)

    E-mail: Maurizio.DeSanctis@roma1.infn.it. MS received 3 September 2008; accepted 14 October 2008. Abstract. We developed a constituent quark–diquark model for the nucleon and its resonances using a harmonic oscillator potential for the interaction. The effects due to relativistic kinetic energy correction are studied.

  7. Nuclear matter EoS including few-nucleon correlations

    Science.gov (United States)

    Röpke, G.

    2017-11-01

    Improving a mean-field approach to the nuclear matter equation of state (EoS), few-nucleon correlations are investigated. The contribution of clusters to the thermodynamic properties is suppressed at increasing density because of Pauli blocking. Continuum correlations are implemented. Applications to heavy-ion collisions (HIC) are discussed.

  8. Fragmentation Cross Sections of 290 and 400 MeV/nucleon 12C Beamson Elemental Targets

    Energy Technology Data Exchange (ETDEWEB)

    Zeitlin, C.; Guetersloh, S.; Heilbronn, L.; Miller, J.; Fukumura,A.; Iwata, Y.; Murakami, T.

    2007-03-17

    Charge-changing and fragment production cross sections at 0circ have been obtained for interactions of 290 MeV/nucleon and 400MeV/nucleon carbon beams with C, CH2, Al, Cu, Sn, and Pb targets. Thesebeams are relevant to cancer therapy, space radiation, and the productionof radioactive beams. We compare to previously published results using Cand CH2 targets at similar beam energies. Due to ambiguities arising fromthe presence of multiple fragments on many events, previous publicationshave reported only cross sections for B and Be fragments. In this work wehave extracted cross sections for all fragment species, using dataobtained at three distinct values of angular acceptance, supplemented bydata taken with the detector stack placed off the beam axis. A simulationof the experiment with the PHITS Monte Carlo code shows fair agreementwith the data obtained with the large acceptance detectors, but agreementis poor at small acceptance. The measured cross sections are alsocompared to the predictions of the one-dimensional cross section modelsEPAX2 and NUCFRG2; the latter is presently used in NASA's space radiationtransport calculations. Though PHITS and NUCFRG2 reproduce thecharge-changing cross sections with reasonable accuracy, none of themodels is able to accurately predict the fragment cross sections for allfragment species and target materials.

  9. (Multi-nucleon transfer in the reactions 16O, 32S+208Pb

    Directory of Open Access Journals (Sweden)

    Hinde D.J.

    2011-10-01

    Full Text Available A detailed analysis of the projectile-like fragments detected at backward angles in the reactions 16O,32 S+208Pb at energies below the fusion barrier is presented. Excitation functions corresponding to nucleon transfer with ∆Z = 1 and ∆Z = 2 were extracted, indicating surprisingly large absolute probabilities at subbarrier energies. A comparison of 2p transfer probabilities with time-dependent Hartree-Fock calculations suggests strong pairing correlations between the two protons. Excitation energies in the projectile-like fragments ~15 MeV and ~25 MeV for the 16O and 32S-induced reactions, respectively, indicate the population of highly excited states in the residual nuclei. A comparison with expected optimum Q-values suggests large losses in kinetic energy of the projectile-like fragments. These highly inelastic (large excitation energies and complex (correlated few-nucleon transfer processes may be closely related to the depletion of fusion through tunnelling at sub-barrier energies.

  10. Magnetic solid-phase extraction of brominated flame retardants from environmental waters with graphene-doped Fe3O4 nanocomposites.

    Science.gov (United States)

    Yang, Jing; Qiao, Jun-qin; Cui, Shi-hai; Li, Jia-yuan; Zhu, Jin-jin; Yin, He-xing; Zhan, Cheng-yan; Lian, Hong-zhen

    2015-06-01

    Graphene-doped Fe3O4 nanocomposites were prepared by a solvothermal reaction of an iron source with graphene. The nanocomposites were characterized by transmission electron microscopy, atomic force microscopy, X-ray diffraction, superconducting quantum interference, Raman spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. This nanomaterial has been used as a magnetic solid-phase extraction sorbent to extract trace brominated flame retardants from environmental waters. Various extraction parameters were optimized including dosage and reusability of the nanocomposites, and pH of sample matrix. The reliability of the magnetic solid-phase extraction protocol based on graphene-doped Fe3O4 nanocomposites was evaluated by investigating the recoveries of 2,4,6-tribromophenol, tetrabromobisphenol A, 4-bromodiphenyl ether, and 4,4'-dibromodiphenyl ether in water samples. Good recoveries (85.0-105.0%) were achieved with the relative standard deviation ranging from 1.1-7.1%. Moreover, it is speculated from characterization and magnetic solid-phase extraction experiment that there is not only π-π stacking but also possible hydrophobic interaction between the graphene-doped Fe3O4 nanocomposites and analytes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. MAGNET

    CERN Multimedia

    B. Curé

    2011-01-01

    The magnet ran smoothly in the last few months until a fast dump occurred on 9th May 2011. Fortunately, this occurred in the afternoon of the first day of the technical stop. The fast dump was due to a valve position controller that caused the sudden closure of a valve. This valve is used to regulate the helium flow on one of the two current leads, which electrically connects the coil at 4.5 K to the busbars at room temperature. With no helium flow on the lead, the voltage drop and the temperatures across the leads increase up to the defined thresholds, triggering a fast dump through the Magnet Safety System (MSS). The automatic reaction triggered by the MSS worked properly. The helium release was limited as the pressure rise was just at the limit of the safety valve opening pressure. The average temperature of the magnet reached 72 K. It took four days to recover the temperature and refill the helium volumes. The faulty valve controller was replaced by a spare one before the magnet ramp-up resumed....

  12. One-pot synthesis of magnetic zeolitic imidazolate framework/grapheme oxide composites for the extraction of neonicotinoid insecticides from environmental water samples.

    Science.gov (United States)

    Cao, Xiaolin; Jiang, Zejun; Wang, Shanshan; Hong, Sihui; Li, Hui; Shao, Yong; She, Yongxin; Wang, Jing; Jin, Fen; Jin, Maojun

    2017-12-01

    Magnetic zeolitic imidazolate framework 67/graphene oxide composites were synthesized by one-pot method at room temperature for the first time. Electrostatic interactions between positively charged metal ions and both negatively charged graphene oxide and Fe 3 O 4 nanoparticles were expected to chemically stabilize magnetic composites to generate homogeneous magnetic products. The additional amount of graphene oxide and stirring time of graphene oxide, Co 2+ , and Fe 3 O 4 solution were investigated. The zeolitic imidazolate framework 67 and Fe 3 O 4 nanoparticles were uniformly attached on the surface of graphene oxide. The composites were applied to magnetic solid-phase extraction of five neonicotinoid insecticides in environmental water samples. The main experimental parameters such as amount of added magnetic composites, extraction pH, ionic strength, and desorption solvent were optimized to increase the capacity of adsorbing neonicotinoid insecticides. The results show limits of detection at signal-to-noise ratio of 3 were 0.06-1.0 ng/mL under optimal conditions. All analytes exhibited good linearity with correlation coefficients of higher than 0.9915. The relative standard deviations for five neonicotinoid insecticides in environmental samples ranged from 1.8 to 16.5%, and good recoveries from 83.5 to 117.0% were obtained, indicating that magnetic zeolitic imidazolate framework 67/graphene oxide composites were feasible for analysis of trace analytes in environmental water samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Preparation of Fe3O4@C@PANI magnetic microspheres for the extraction and analysis of phenolic compounds in water samples by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Meng, Jiaoran; Shi, Chenyi; Wei, Biwen; Yu, Wenjia; Deng, Chunhui; Zhang, Xiangmin

    2011-05-20

    In this work, core-shell structure Fe(3)O(4)@C@polyaniline magnetic microspheres were synthesized using simple hydrothermal reactions. The carbon-coated magnetic microspheres (Fe(3)O(4)@C) were first synthesized by a hydrothermal reaction, and then aniline was polymerized on the magnetic core via another hydrothermal reaction. Then, the obtained Fe(3)O(4)@C@polyaniline magnetic microspheres were applied as magnetic adsorbents for the extraction of aromatic molecules due to π-π interactions between polyaniline shell and aromatic compounds. In our study, five kinds of phenols including phenol, 2,4-dichlorophenol (DCP), 2,4,5-trichlorophenol (TCP), pentachlorophenol (PCP) and bisphenol A (BPA) were selected as the model analytes to verify the extraction ability of Fe(3)O(4)@C@PANI microspheres. After derivatization, the phenols were detected using gas chromatography-mass spectrometry (GC-MS). The dominant parameters affecting enrichment efficiency were investigated and optimized. Under the optimal conditions, the proposed method was evaluated, and applied to the analysis of phenols in real water samples. The results demonstrated that our proposed method based on Fe(3)O(4)@C@polyaniline magnetic microspheres had good linearity (r(2)>0.991), and limits of quantification (2.52-29.7 ng/mL), high repeatability (RSD<13.1%) and good recovery (85.3-110.6%). Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Nucleon-deuteron scattering with the JISP16 potential

    Science.gov (United States)

    Skibiński, R.; Golak, J.; Topolnicki, K.; Witała, H.; Volkotrub, Yu.; Kamada, H.; Shirokov, A. M.; Okamoto, R.; Suzuki, K.; Vary, J. P.

    2018-01-01

    The nucleon-nucleon J -matrix inverse scattering potential JISP16 is applied to elastic nucleon-deuteron scattering and the deuteron breakup process at the laboratory nucleon energies up to 135 MeV. The formalism of the Faddeev equations is used to obtain three-nucleon scattering states. We compare predictions based on the JISP16 force with data and with results based on various two-body interactions, including the CD Bonn, the Argonne AV18, the chiral force with the semilocal regularization at the fifth order of the chiral expansion and with low-momentum interactions obtained from the CD Bonn force as well as with the predictions from the combination of the AV18 NN interaction and the Urbana IX 3 N force. JISP16 provides a satisfactory description of some observables at low energies but strong deviations from data as well as from standard and chiral potential predictions with increasing energy. However, there are also polarization observables at low energies for which the JISP16 predictions differ from those based on the other forces by a factor of two. The reason for such a behavior can be traced back to the P -wave components of the JISP16 force. At higher energies the deviations can be enhanced by an interference with higher partial waves and by the properties of the JISP16 deuteron wave function. In addition, we compare the energy and angular dependence of predictions based on the JISP16 force with the results of the low-momentum interactions obtained with different values of the momentum cutoff parameter. We found that such low-momentum forces can be employed to interpret the nucleon-deuteron elastic scattering data only below some specific energy which depends on the cutoff parameter. Since JISP16 is defined in a finite oscillator basis, it has properties similar to low momentum interactions and its application to the description of nucleon-deuteron scattering data is limited to a low momentum transfer region.

  15. Nucleon Transition Form Factors and New Perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Gothe, R W

    2007-10-01

    The status of the electro-excitation program to study baryon resonances at Jefferson Lab will be exemplified by the most recent results on resonance parameters and transition form factors in single and double-pion production. These results demonstrate that the separation of resonance and background contributions and therefore the extraction of the electro-coupling amplitudes of resonances become easier and cleaner at higher four-momentum transfers (Q2). Furthermore, the double-pion in comparison to the single-pion channel shows a higher sensitivity to higher excited resonances and a distinctly different Q2 dependence of the background amplitudes. The combined analysis of the single- and double-pion data reduces model dependent uncertainties significantly, which allows us to extract the resonant electrocoupling amplitudes with an unprecedented quality.

  16. Pattern recognition analysis of proton nuclear magnetic resonance spectra of brain tissue extracts from rats anesthetized with propofol or isoflurane.

    Directory of Open Access Journals (Sweden)

    Hiroshi Kawaguchi

    Full Text Available BACKGROUND: General anesthesia is routinely used as a surgical procedure and its safety has been endorsed by clinical outcomes; however, its effects at the molecular level have not been elucidated. General anesthetics influence glucose metabolism in the brain. However, the effects of anesthetics on brain metabolites other than those related to glucose have not been well characterized. We used a pattern recognition analysis of proton nuclear magnetic resonance spectra to visualize the changes in holistic brain metabolic phenotypes in response to the widely used intravenous anesthetic propofol and the volatile anesthetic isoflurane. METHODOLOGY/PRINCIPAL FINDINGS: Rats were randomized into five groups (n = 7 each group. Propofol and isoflurane were administered to two groups each, for 2 or 6 h. The control group received no anesthesia. Brains were removed directly after anesthesia. Hydrophilic compounds were extracted from excised whole brains and measured by proton nuclear magnetic resonance spectroscopy. All spectral data were processed and analyzed by principal component analysis for comparison of the metabolite profiles. Data were visualized by plotting principal component (PC scores. In the plots, each point represents an individual sample. The propofol and isoflurane groups were clustered separately on the plots, and this separation was especially pronounced when comparing the 6-h groups. The PC scores of the propofol group were clearly distinct from those of the control group, particularly in the 6-h group, whereas the difference in PC scores was more subtle in the isoflurane group and control groups. CONCLUSIONS/SIGNIFICANCE: The results of the present study showed that propofol and isoflurane exerted differential effects on holistic brain metabolism under anesthesia.

  17. Generalized folding model for elastic and inelastic nucleus-nucleus scattering using realistic density dependent nucleon-nucleon interaction

    CERN Document Server

    Khoa, D T

    2000-01-01

    A generalized double-folding model for elastic and inelastic nucleus-nucleus scattering is presented. It is designed to accommodate effective nucleon-nucleon (NN) interactions that depend upon the density of nuclear matter in which the two nucleons are immersed. A recently parametrized density dependent M3Y interaction, based on the G-matrix elements of the Paris NN potential, has been used in the present folding calculation. The effects of knock-on exchange of the interacting nucleon pair are included in an accurate local approximation. Examples of the application of this model to study the refractive elastic and inelastic scattering data of sup 1 sup 2 C+ sup 1 sup 2 C and alpha+ sup 5 sup 8 sup , sup 6 sup 0 Ni systems are presented. A detailed comparison of the use of deformed optical potential (DP) and microscopic folded potential in the analysis of inelastic scattering has shown that the use of DP fails to reproduce the inelastic sup 1 sup 2 C+ sup 1 sup 2 C scattering data measured over a wide angular ...

  18. Weak production of strange particles and η mesons off the nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Alam, M. Rafi; Athar, M. Sajjad [Department of Physics, Aligarh Muslim University, Aligarh-202 002 (India); Simo, I. Ruiz [Departamento de Física Atómica, Moleculary Nuclear, and Instituto de Física Teórica y Computacional Carlos I, Universidad de Granada, Granada 18071 (Spain); Alvarez-Ruso, L.; Vacas, M. J. Vicente [Departamento de Física Teórica and Instituto de Física Corpuscular, Centro Mixto Universidad de Valencia-CSIC, E-46071 Valencia (Spain)

    2015-10-15

    The strange particle production induced by (anti)neutrino off nucleon has been studied for |ΔS| = 0 and |ΔS| = 1 channels. The reactions those we have considered are for the production of single kaon/antikaon, eta and associated particle production processes. We have developed a microscopical model based on the SU(3) chiral Lagrangian. The basic parameters of the model are f{sub π}, the pion decay constant, Cabibbo angle, the proton and neutron magnetic moments and the axial vector coupling constants for the baryons octet. For antikaon production we have also included Σ*(1385) resonance and for eta production S{sub 11}(1535) and S{sub 11}(1650) resonances are included.

  19. A measurement of the neutral current neutrino-nucleon elastic cross section at MiniBooNE

    Energy Technology Data Exchange (ETDEWEB)

    Cox, David Christopher [Indiana Univ., Bloomington, IN (United States)

    2008-02-01

    The neutral current neutrino-nucleon elastic interaction v N → v N is a fundamental process of the weak interaction ideally suited for characterizing the structure of the nucleon neutral weak current. This process comprises ~18% of neutrino events in the neutrino oscillation experiment, MiniBooNE, ranking it as the experiment's third largest process. Using ~10% of MiniBooNE's available neutrino data, a sample of these events were identified and analyzed to determine the differential cross section as a function of the momentum transfer of the interaction, Q2. This is the first measurement of a differential cross section with MiniBooNE data. From this analysis, a value for the nucleon axial mass MA was extracted to be 1.34 ± 0.25 GeV consistent with previous measurements. The integrated cross section for the Q2 range 0.189 → 1.13 GeV2 was calculated to be (8.8 ± 0.6(stat) ± 0.2(syst)) x 10-40 cm2.

  20. Preparation and characterization of magnetic Wells-Dawson heteropoly acid nanoparticles for magnetic solid-phase extraction of aromatic amines in water samples.

    Science.gov (United States)

    Amiri, Amirhassan; Saadati-Moshtaghin, Hamid Reza; Zonoz, Farokhzad Mohammadi; Targhoo, Azadeh

    2017-02-03

    In this work, aminopropyl modified silica-coated magnetite nanoparticles with Wells-Dawson heteropoly acid (P2W17Fe@APSCMNPs) was first synthesized and underwent highly efficient magnetic solid-phase extraction (MSPE) of aromatic amines from aqueous samples. The resulted nanomaterials were characterized with different physicochemical techniques such as Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). Aniline, N,N-dimethylaniline, o-toluidine and 3-chloroaniline were selected as target compounds. The sample quantification was carried out using gas chromatography-flame ionization detector (GC-FID). Under optimal working conditions, the developed method showed good linearity (R>0.9912) in the range of 0.01-100ngmL(-1). The method displays detection limits (at an S/N ration of 3) in the range from 0.003 to 0.01ngmL(-1), and the limits of quantification (at an S/N ratio of 10) are between 0.01 and 0.04ngmL(-1). The enrichment factors (EFs) were in the range of 75-113. Relative standard deviations (RSDs) are 4.8-8.3%. The applicability of the developed method was examined by analyzing different water samples (river water, tap water, well water and wastewater) and the relative recovery values for the spiked water samples were found to be in the range of 90.7-99.8%. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. MAGNET

    CERN Multimedia

    B. Curé

    MAGNET During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bough...

  2. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    The magnet worked very well at 3.8 T as expected, despite a technical issue that manifested twice in the cryogenics since June. All the other magnet sub-systems worked without flaw. The issue in the cryogenics was with the cold box: it could be observed that the cold box was getting progressively blocked, due to some residual humidity and air accumulating in the first thermal exchanger and in the adsorber at 65 K. This was later confirmed by the analysis during the regeneration phases. An increase in the temperature difference between the helium inlet and outlet across the heat exchanger and a pressure drop increase on the filter of the adsorber were observed. The consequence was a reduction of the helium flow, first compensated by the automatic opening of the regulation valves. But once they were fully opened, the flow and refrigeration power reduced as a consequence. In such a situation, the liquid helium level in the helium Dewar decreased, eventually causing a ramp down of the magnet current and a field...

  3. MAGNET

    CERN Multimedia

    Benoit Curé.

    The magnet operation restarted end of June this year. Quick routine checks of the magnet sub-systems were performed at low current before starting the ramps up to higher field. It appeared clearly that the end of the field ramp down to zero was too long to be compatible with the detector commissioning and operations plans. It was decided to perform an upgrade to keep the ramp down from 3.8T to zero within 4 hours. On July 10th, when a field of 1.5T was reached, small movements were observed in the forward region support table and it was decided to fix this problem before going to higher field. At the end of July the ramps could be resumed. On July 28th, the field was at 3.8T and the summer CRAFT exercise could start. This run in August went smoothly until a general CERN wide power cut took place on August 3rd, due to an insulation fault on the high voltage network outside point 5. It affected the magnet powering electrical circuit, as it caused the opening of the main circuit breakers, resulting in a fast du...

  4. MAGNET

    CERN Multimedia

    B. Curé

    2013-01-01

    The magnet is fully stopped and at room temperature. The maintenance works and consolidation activities on the magnet sub-systems are progressing. To consolidate the cryogenic installation, two redundant helium compressors will be installed as ‘hot spares’, to avoid the risk of a magnet downtime in case of a major failure of a compressor unit during operation. The screw compressors, their motors, the mechanical couplings and the concrete blocks are already available and stored at P5. The metallic structure used to access the existing compressors in SH5 will be modified to allow the installation of the two redundant ones. The plan is to finish the installation and commissioning of the hot spare compressors before the summer 2014. In the meantime, a bypass on the high-pressure helium piping will be installed for the connection of a helium drier unit later during the Long Shutdown 1, keeping this installation out of the schedule critical path. A proposal is now being prepared for the con...

  5. Determination of type A trichothecenes in coix seed by magnetic solid-phase extraction based on magnetic multi-walled carbon nanotubes coupled with ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Dong, Maofeng; Si, Wenshuai; Wang, Weimin; Bai, Bing; Nie, Dongxia; Song, Weiguo; Zhao, Zhihui; Guo, Yirong; Han, Zheng

    2016-09-01

    Magnetic solid-phase extraction (m-SPE) is a promising sample preparation approach due to its convenience, speed, and simplicity. For the first time, a rapid and reliable m-SPE approach using magnetic multi-walled carbon nanotubes (m-MWCNTs) as the adsorbent was proposed for purification of type A trichothecenes including T-2 toxins (T2), HT-2 toxins (HT-2), diacetoxyscirpenol (DAS), and neosolaniol (NEO) in coix seed. The m-MWCNTs were synthesized by assembling the magnetic nanoparticles (Fe3O4) with MWCNTs by sonication through an aggregation wrap mechanism, and characterized by transmission electron microscope. Several key parameters affecting the performance of the procedure were extensively investigated including extraction solutions, desorption solvents, and m-MWCNT amounts. Under the optimal sample preparation conditions followed by analysis with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), high sensitivity (limit of quantification in the range of 0.3-1.5 μg kg(-1)), good linearity (R (2) > 0.99), satisfactory recovery (73.6-90.6 %), and acceptable precision (≤2.5 %) were obtained. The analytical performance of the developed method has also been successfully evaluated in real coix seed samples. Graphical Abstract Flow chart of determination of type A trichothecenes in coix seed by magnetic solid-phase extraction coupled with ultra-high performance liquid chromatography-tandem mass spectrometry.

  6. Extracting magnetic anomalies based on an improved BEMD method: A case study in the Pangxidong Area, South China

    Science.gov (United States)

    Hou, Weisheng; Yang, Zhijun; Zhou, Yongzhang; Zhang, Liping; Wu, Wenlong

    2012-11-01

    In bidimensional empirical mode decomposition, an appropriate stoppage criterion for the sifting process is important. To solve the problem of unstable convergence, a stepwise stop criterion was presented based on the Cauchy-type criterion. In one sifting process, a squared deviation of two successive residual components is first calculated. Then, an absolute value of the difference between two continuous deviations is calculated. The sifting process will stop when the difference value is less than the a priori value. A comparison of correlation coefficients of the final results decomposed from experimental models demonstrated that those intrinsic mode functions obtained by the stepwise stop criterion meet the requirements of orthogonality, and the mode mixing effect among them is depressed effectively. With the help of the proposed criterion, an example is given for extracting magnetic anomalies in the Pangxidong area, Guangdong Province, South China. The residual components of the first and second order of bidimensional intrinsic mode functions revealed a spatial relationship between ore deposits and anomalies.

  7. A sensitive and selective spectrophotometric method for 2-chlorophenol based on solid phase extraction with mixed hemimicelle magnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    Siriboon Mukdasai

    2016-05-01

    Full Text Available The first study of a sensitive and selective spectrophotometric detection of 2-chlorophenol (2-CP was reported. The method is based on derivatization of 2-CP with 4-aminoantipyrine (4-AAP and subsequent preconcentration by solid phase extraction (SPE using mixed hemimicelles adsorbent of cetyltrimethylammonium bromide coated magnetic nanoparticles (CTAB coated Fe3O4 NPs before its detection by spectrophotometry at 510 nm. The adsorption capacity was evaluated using the Langmuir adsorption isotherm model, with high correlation coefficients (R2 = 0.9983. The optimum conditions for SPE were CTAB coated Fe3O4 NPs 20 mg under vortex 60 s and methanol as the desorption solvent under sonication for 7 min. The linearity of the method was in the range of 0.05–1.0 mg L−1 with correlation coefficient (0.9970. The limit of detection (LOD and limit of quantitation (LOQ were 0.01 mg L−1 and 0.05 mg L−1, respectively. Good precision with relative standard deviation (%RSD, n = 5 less than 3.7% was obtained. The method was successfully applied for the determination of 2-CP in soil samples with satisfactory recoveries (81.7–95.2%.

  8. A novel technique for injecting and extracting beams in a circular hadron accelerator without using septum magnets

    CERN Document Server

    AUTHOR|(SzGeCERN)395725

    2015-01-01

    With a few exceptions, all on-axis injection and extraction schemes implemented in circular particle accelerators, synchrotrons, and storage rings, make use of magnetic and electrostatic septa with systems of slow-pulsing dipoles acting on tens of thousands of turns and fast-pulsing dipoles on just a few. The dipoles create a closed orbit deformation around the septa, usually referred to as an orbit bump. A new approach is presented which obviates the need for the septum deflectors. Fastpulsing elements are still required, but their strength can be minimized by choosing appropriate local accelerator optics. This technique should increase the beam clearance and reduce the usually high radiation levels found around the septa and also reduce the machine impedance introduced by the fast-pulsing dipoles. The basis of the technique is the creation of stable islands around stable fixed points in horizontal phase space. The trajectories of these islands may then be adjusted to match the position and angle of the inco...

  9. Screening of lipase inhibitors from Scutellaria baicalensis extract using lipase immobilized on magnetic nanoparticles and study on the inhibitory mechanism.

    Science.gov (United States)

    Wan, Li-Hong; Jiang, Xiao-Lan; Liu, Yi-Ming; Hu, Jin-Jie; Liang, Jian; Liao, Xun

    2016-03-01

    Scutellaria baicalensis is a traditional Chinese medicinal plant possessing a wide variety of biological activities. In this work, lipase immobilized on magnetic nanoparticles (LMNPs) was used as solid phase extract absorbent for screening of lipase inhibitors from this plant. Three flavonoids were found to bind to LMNPs and were identified as baicalin, wogonin, and oroxylin A by liquid chromatography-mass spectrometry (HPLC-MS). Their IC50 values were determined to be 229.22 ± 12.67, 153.71 ± 9.21, and 56.07 ± 4.90 μM, respectively. Fluorescence spectroscopy and molecular docking were used to probe the interactions between these flavonoids and lipase. All the flavonoids quenched the fluorescence of lipase statically by forming new complexes, implying their affinities with the enzyme. The thermodynamic analysis suggested that van der Waals force and hydrogen bond were the main forces between wogonin and lipase, while hydrophobic force was the main force for the other two flavonoids. The results from a molecular docking study further revealed that all of them could insert into the pocket of lipase binding to a couple of amino acid residues.

  10. Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

    Science.gov (United States)

    Kistrup, Kasper; Skotte Sørensen, Karen; Wolff, Anders; Fougt Hansen, Mikkel

    2015-04-01

    We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible phase filtration and features passive liquid filling and magnetic bead manipulation using an external magnet. In this work, we determine the system compatibility with various surfactants. Moreover, we quantify the volume of liquid co-transported with magnetic bead clusters from Milli-Q water or a lysis-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/μg and 1.72(14) nL/μg were found for Milli-Q water and lysis-binding buffer, respectively.

  11. Solid phase extraction and trace monitoring of cadmium ions in environmental water and food samples based on modified magnetic nanoporous silica

    Energy Technology Data Exchange (ETDEWEB)

    Omidi, Fariborz [Department of Occupational Health Engineering, School of Public Health, Shahroud University of Medical Sciences, Shahroud (Iran, Islamic Republic of); Behbahani, Mohammad, E-mail: mohammadbehbahai89@yahoo.com [Department of Chemistry, Shahid Beheshti University, Evin, Tehran (Iran, Islamic Republic of); Kalate Bojdi, Majid [Faculty of Chemistry, Kharazmi (Tarbiat Moallem) University, Tehran (Iran, Islamic Republic of); Shahtaheri, Seyed Jamaleddin [Department of Occupational Health Engineering, School of Public Health and Institute for Environmental Research, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2015-12-01

    A new method has been developed for trace separation/preconcentration of cadmium ions using pyridine-functionalized magnetic nanoporous silica material (called Py-Fe{sub 3}O{sub 4}@MCM-41) as a new magnetic sorbent and their determination by flame atomic absorption spectrometry (FAAS). The Py-Fe{sub 3}O{sub 4}@MCM-41 sorbent was characterized by thermogravimetric analysis, differential thermal analysis, transmission electron microscopy, Fourier transform infrared spectrometry and X-ray diffraction. The modified Fe{sub 3}O{sub 4}@MCM-41 can be easily separated from an aqueous solution by applying an external magnetic field. Effects of pH, amount of functionalized Fe{sub 3}O{sub 4}@MCM-41, extraction time, type and quantity of eluent, desorption time, and interfering ions on the extraction efficiency were evaluated and optimized. Under the optimized conditions, the detection limit and relative standard deviation was 0.04 μg L{sup –1} and 2.9%, respectively and the maximum adsorption capacity of the synthesized sorbent for cadmium ions was 154 mg g{sup −1}. The proposed method has been applied to the determination of Cd ions at trace levels in real samples such as, rice, onion, carrot, lettuce, parsley, basil, tap water, river water and seawater with satisfactory results. - Highlights: • The introducing of modified magnetic mesoporous silica as a novel magnetic sorbent. • Trace monitoring of cadmium ions. • The limit of detection (LOD) by the proposed solid phase extraction method was 0.04 ng mL{sup −1} for the cadmium ions. • High surface areas and magnetic characteristic of the sorbent. • Maximum adsorption capacity of the sorbent was 154 mg g{sup −1}.

  12. Nucleon structure in terms of OPE with non-perturbative Wilson coefficients

    Energy Technology Data Exchange (ETDEWEB)

    Bietenholz, W. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC]|[Regensburg Univ. (Germany). Inst. fuer Physik 1 - Theoretische Physik; Cundy, N.; Goeckeler, M. [Regensburg Univ. (Germany). Inst. fuer Physik 1 - Theoretische Physik; Horsley, R.; Zanotti, J.M. [Edinburgh Univ. (United Kingdom). School of Physics; Perlt, H.; Schiller, A. [Leipzig Univ. (Germany). Inst. fuer Theoretische Physik; Pleiter, D.; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Division, Dept. of Mathematical Sciences

    2008-10-15

    Lattice calculations could boost our understanding of Deep Inelastic Scattering by evaluating moments of the Nucleon Structure Functions. To this end we study the product of electromagnetic currents between quark states. The Operator Product Expansion (OPE) decomposes it into matrix elements of local operators (depending on the quark momenta) and Wilson coefficients (as functions of the larger photon momenta). For consistency with the matrix elements, we evaluate a set of Wilson coefficients non-perturbatively, based on propagators for numerous momentum sources, on a 24{sup 3} x 48 lattice. The use of overlap quarks suppresses unwanted operator mixing and lattice artifacts. Results for the leading Wilson coefficients are extracted by means of Singular Value Decomposition. (orig.)

  13. Measuring one nucleon transfer reaction 24Mg( p, d)23Mg for astrophysical reaction rates

    Science.gov (United States)

    Lee, E. J.; Chae, K. Y.

    2017-12-01

    The level structure of a radionuclide 23Mg has been studied by using the 24Mg( p, d)23Mg one nucleon transfer reaction measurement for the astrophysical 19Ne(α, γ)23Mg reaction rate. A 41 MeV proton beam was produced and accelerated at the 25 MV tandem accelerator of the Holifield Radioactive Ion Beam Facility of the Oak Ridge National Laboratory in the United States. The beam particles impinged on an isotopically-enriched 24Mg solid target. Angular distributions of recoiling deuterons were extracted by using a large area silicon strip detector array. By comparing the experimentally-obtained angular distributions with zero range distorted wave Born approximation calculations, spins and parities of three energy levels of 23Mg could be constrained for the first time, which is very important information needed to understand the 19Ne(α, γ)23Mg reaction rate.

  14. Nucleon-Nucleus Scattering and Dirac Phenomenology: What We Have Learned and What Remains

    Science.gov (United States)

    Clark, B. C.; Kerr, Lisa K.; Hama, S.

    2005-05-01

    It is now generally recognized that the Dirac equation is a viable alternative to the usual Schrödinger equation approach for analyzing nucleon-nucleus scattering data. This paper reviews the development of Dirac phenomenology, stressing how closely this development has been tied to experiment. In addition we discuss a new method for extracting neutron densities from intermediate energy elastic proton-nucleus scattering observables uses a global Dirac phenomenological (DP) approach based on the Relativistic Impulse Approximation (RIA). Data sets for 40Ca, 48Ca and 208Pb in the energy range from 500 MeV to 1040 MeV are used. The global fits reproducing the data well and this allows one to obtain the proton and neutron densities, their root-mean-square radii, Rp and Rn, and the neutron skin thickness, Sn = Rn - Rp.

  15. Hadronic Expansion Dynamics in Central Pb+Pb Collisions at 158 GeV per Nucleon

    CERN Document Server

    Appelshäuser, H; Bailey, S J; Barnby, L S; Bartke, Jerzy; Barton, R A; Bialkowska, H; Billmeier, A; Blyth, C O; Bock, R; Bormann, C; Brady, F P; Brockmann, R; Brun, R; Buncic, P; Caines, H L; Cebra, D; Cooper, G E; Cramer, J G; Csató, P; Dunn, J; Eckardt, V; Eckhardt, F; Ferguson, M I; Ferenc, D; Fischer, H G; Flierl, D; Fodor, Z; Foka, P Y; Freund, P; Friese, V; Fuchs, M; Gabler, F; Gál, J; Gazdzicki, M; Gladysz-Dziadus, E; Grebieszkow, J; Günther, J; Harris, J W; Hegyi, S; Henkel, T; Hill, L A; Huang, I; Hümmler, H; Igo, G; Irmscher, D; Jacobs, P; Jones, P G; Kadija, K; Kolesnikov, V I; Kowalski, M; Lasiuk, B; Lévai, Peter; Malakhov, A I; Margetis, S; Markert, C; Melkumov, G L; Mock, A; Molnár, J; Nelson, J M; Oldenburg, M; Odyniec, Grazyna Janina; Pálla, G; Panagiotou, A D; Petridis, A; Piper, A; Porter, R J; Poskanzer, A M; Poziombka, S; Prindle, D J; Pühlhofer, F; Rauch, W; Reid, J G; Renfordt, R E; Retyk, W; Ritter, H G; Röhrich, D; Roland, C; Roland, G; Rudolph, H; Rybicki, A; Sandoval, A; Sann, H; Semenov, A Yu; Schäfer, E; Schmischke, D; Schmitz, N; Schönfelder, S; Seyboth, P; Seyerlein, J; Siklér, F; Skrzypczak, E; Squier, G T A; Stock, Reinhard; Ströbele, H; Struck, C; Szentpétery, I; Sziklai, J; Toy, M; Trainor, T A; Trentalange, S; Ullrich, T S; Vassiliou, Maria; Vesztergombi, G; Vranic, D; Wang, F; Weerasundara, D D; Wenig, S; Whitten, C; Wienold, T; Wood, L; Yates, T A; Xu, N; Zimányi, J; Zhu, X Z; Zybert, R

    1998-01-01

    Two-particle correlation functions of negative hadrons over wide phase space, and transverse mass spectra of negative hadrons and deuterons near mid-rapidity have been measured in central Pb+Pb collisions at 158 GeV per nucleon by the NA49 experiment at the CERN SPS. A novel Coulomb correction procedure for the negative two-particle correlations is employed making use of the measured oppositely charged particle correlation. Within an expanding source scenario these results are used to extract the dynamic characteristics of the hadronic source, resolving the ambiguities between the temperature and transverse expansion velocity of the source, that are unavoidable when single and two particle spectra are analysed separately. The source shape, the total duration of the source expansion, the duration of particle emission, the freeze-out temperature and the longitudinal and transverse expansion velocities are deduced.

  16. Surfactant-enhanced spectrofluorimetric determination of total aflatoxins from wheat samples after magnetic solid-phase extraction using modified Fe₃O₄ nanoparticles.

    Science.gov (United States)

    Manafi, Mohammad Hanif; Allahyari, Mehdi; Pourghazi, Kamyar; Amoli-Diva, Mitra; Taherimaslak, Zohreh

    2015-07-05

    The extraction and preconcentration of total aflatoxins (including aflatoxin B1, B2, G1, and G2) using magnetic nanoparticles based solid phase extraction (MSPE) followed by surfactant-enhanced spectrofluorimetric detection was proposed. Ethylene glycol bis-mercaptoacetate modified silica coated Fe3O4 nanoparticles as an efficient antibody-free adsorbent was successfully applied to extract aflatoxins from wheat samples. High surface area and strong magnetization properties of magnetic nanoparticles were utilized to achieve high enrichment factor (97), and satisfactory recoveries (92-105%) using only 100mg of the adsorbent. Furthermore, the fast separation time (less than 10 min) avoids many time-consuming cartridge loading or column-passing procedures accompany with the conventional SPE. In determination step, signal enhancement was performed by formation of Triton X-100 micelles around the analytes in 15% (v/v) acetonitrile-water which dramatically increase the sensitivity of the method. Main factors affecting the extraction efficiency and signal enhancement of the analytes including pH of sample solution, desorption conditions, extraction time, sample volume, adsorbent amount, surfactant concentration and volume and time of micelle formation were evaluated and optimized. Under the optimum conditions, wide linear range of 0.1-50 ng mL(-1) with low detection limit of 0.03 ng mL(-1) were obtained. The developed method was successfully applied to the extraction and preconcentration of aflatoxins in three commercially available wheat samples and the results were compared with the official AOAC method. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. MAGNET

    CERN Multimedia

    Benoit Curé

    The magnet subsystems resumed operation early this spring. The vacuum pumping was restarted mid March, and the cryogenic power plant was restarted on March 30th. Three and a half weeks later, the magnet was at 4.5 K. The vacuum pumping system is performing well. One of the newly installed vacuum gauges had to be replaced at the end of the cool-down phase, as the values indicated were not coherent with the other pressure measurements. The correction had to be implemented quickly to be sure no helium leak could be at the origin of this anomaly. The pressure measurements have been stable and coherent since the change. The cryogenics worked well, and the cool-down went quite smoothly, without any particular difficulty. The automated start of the turbines had to be fine-tuned to get a smooth transition, as it was observed that the cooling power delivered by the turbines was slightly higher than needed, causing the cold box to stop automatically. This had no consequence as the cold box safety system acts to keep ...

  18. MAGNET

    CERN Multimedia

    B. Curé

    During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bought. Th...

  19. Magnetic microsphere-based portable solid phase extraction device for on-site pre-concentration of organics from large-volume water samples.

    Science.gov (United States)

    Yao, Zhijian; Zhao, Qingqing; Ma, Yan; Wang, Wei; Zhou, Qing; Li, Aimin

    2017-08-14

    In this research a new magnetic material called M88 was fully synthetized and characterized for the extraction of pharmaceutical and personal care products in water samples. In addition, a portable prototype of magnetic solidphase extraction (MSPE) device was developed for the onsite preconcentration. The MSPE coupling with high performance liquid chromatography-Diode array detector (HPLC-DAD) method was developed and validated for simultaneous analysis of 11 PPCPs (mefenamic acid, chloroamphenicol, ketoprofen, clofibric acid, indometacin, acetylsalicylic acid, bisphenol A, phenylphenol, gemfibrozil, triclosan, and ibuprofen) in environmental water samples. Experimental parameters affecting the extraction efficiencies, such as the amount of M88, desorption solvent, extraction time, and solution pH and sample volume were investigated. Under the optimal conditions, the limits of detection (LODs, S/N = 3) for the selected PPCPs were found to be in the range of 0.7-9.4 ng/L, with good linear correlation coefficients. It is also shown that the extraction efficiency of M88 was comparable to that of the commercial Oasis HLB and was evidently higher than that of the C18 cartridge. The optimised method was further verified by performing spiking experiments in water samples from Taihu Lake, with good recovery and reproducibility for all the compounds.

  20. Photoproduction of Mesons on Quasi–Free Nucleons

    Directory of Open Access Journals (Sweden)

    Keshelashvili I.

    2014-01-01

    Full Text Available The investigation of excited baryon states is important to understand the underling nature/symmetries of hadronic matter. Historically, the first nucleon excitation experiments have been done using charged pion and kaon secondary beams. Later the antiproton-proton scattering has also been involved. However, since the beginning of the 90’s meson photoproduction reactions have been considered as a powerful tool in baryon spectroscopy. In this contribution, we overview our experimental programs conducted at the bremsstrahlung photon beams of the MAMI accelerator in Mainz and the ELSA accelerator in Bonn. The results are differential and total cross sections for photoproduction of light neutral mesons and of meson pairs off quasi-free nucleons bound in the deuteron (and sometimes other light nuclei. The scientific programs of this experiments also include single and double polarization measurements as well.

  1. Nucleon structure studies with the COMPASS experiment at CERN

    Directory of Open Access Journals (Sweden)

    Platchkov Stephane

    2016-01-01

    Full Text Available The COMPASS experiment at CERN uses hadron and lepton beams for nucleon structure studies. Most of the data collected so far with a muon beam and either proton or deuteron polarised target were analysed in terms of longitudinally or transversely polarised parton distribution functions and transverse momentum-dependent distributions in the nucleon. A negative hadron beam is used to perform Drell-Yan measurements. The COMPASS large polarised target gives access to several momentum-dependent singlespin asymmetries and provides a stringent test of the fundamental QCD factorisation assumptions. With positive and negative muon beams COMPASS also studies Generalised Parton Distributions using exclusive deeply virtual Compton scattering and meson production experiments. An overview of the most recent COMPASS results is given. The expected physics outcome of the forthcoming measurements is discussed.

  2. 11th Workshop on The Physics of Excited Nucleons

    CERN Document Server

    Hammer, Hans-Werner; Thoma, Ulrike; Schmieden, Hartmut; NSTAR 2007

    2008-01-01

    The excitation spectrum of the nucleon promises to offer important insights into the non-perturbative regime of QCD. Dedicated experimental programs at various laboratories exist to perform accurate measurements of meson photo- and electroproduction off the nucleon, studying its excitation. The NStar workshops are a well-established series of meetings that bring together experimenters and theoreticians working on baryon resonances and related areas to discuss New results on pseudoscalar and vector meson production; Partial wave analysis and resonance parameters; Baryon resonance structure and quark models; Dynamical models and coupled channel analysis; Baryon resonances in lattice QCD; Chiral symmetry and baryon resonances; Laboratory reports and future projects. The refereed and edited proceedings constitute an indispensable archival record of the progress in the field.

  3. From Nucleons to Nucleus Concepts of Microscopic Nuclear Theory

    CERN Document Server

    Suhonen, Jouni

    2007-01-01

    From Nucleons to Nucleus deals with single-particle and collective features of spherical nuclei. Each nuclear model is introduced and derived in detail. The formalism is then applied to light and medium-heavy nuclei in worked-out examples, and finally the acquired skills are strengthened by a wide selection of exercises, many relating the models to experimental data. Nuclear properties are discussed using particles, holes and quasiparticles. A large number of matrix elements of standard operators have been tabulated for reference. From Nucleons to Nucleus is based on lectures on nuclear physics given by the author. Its main scope is thus to serve as a textbook for advanced students. But also researchers will appreciate it as wellbalanced reference to theoretical nuclear physics.

  4. Benchmark calculations for polarization observables in three-nucleon scattering

    Energy Technology Data Exchange (ETDEWEB)

    Kievsky, A.; Viviani, M. [Istituto Nazionale di Fisica Nucleare, Piazza Torricelli 2, 56100 Pisa (Italy); Rosati, S. [Dipartimento di Fisica, Universita di Pisa, Piazza Torricelli 2, 56100 Pisa (Italy); Hueber, D. [Los Alamos National Laboratory, M.S. B283, Los Alamos, New Mexico 87545 (United States); Gloeckle, W.; Kamada, H. [Institut fuer Theoretische Physik II, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Witala, H.; Golak, J. [Institute of Physics, Jagellonian University, PL-30059 Cracow (Poland)

    1998-12-01

    High precision benchmark calculations for phase shifts and mixing parameters as well as observables in elastic neutron-deuteron scattering below the deuteron breakup threshold are presented using a realistic nucleon-nucleon potential. Two totally different methods, one using a variational principle in configuration space and the other solving the Faddeev equations in momentum space, are used and compared to each other. The agreement achieved in phase shifts and mixing parameters as well as in the polarization observables is excellent. The extreme sensitivity of the vector analyzing power A{sub y} to small changes of the phase shifts and mixing parameters is pointed out. thinsp {copyright} {ital 1998} {ital The American Physical Society}

  5. Transverse spin structure of the nucleon from lattice QCD simulations

    Energy Technology Data Exchange (ETDEWEB)

    Goeckeler, M.; Schaefer, A. [Regensburg Univ. (Germany). Inst. fuer Physik 1 - Theoretische Physik; Haegeler, P. [Technische Univ. Muenchen, Garching (Germany). Inst. fuer Theoretische Physik; Horsley, R.; Zanotti, J.M. [Edinburgh Univ. (United Kingdom). School of Physics; Nakamura, Y.; Pleiter, D. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Division, Dept. of Mathematical Sciences; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Stueben, H. [Konrad-Zuse-Zentrum fuer Informationstechnik Berlin (ZIB) (Germany)

    2006-12-15

    We present the first calculation in lattice QCD of the lowest two moments of transverse spin densities of quarks in the nucleon. They encode correlations between quark spin and orbital angular momentum. Our dynamical simulations are based on two flavors of clover-improved Wilson fermions and Wilson gluons. We find significant contributions from certain quark helicity flip generalized parton distributions, leading to strongly distorted densities of transversely polarized quarks in the nucleon. In particular, based on our results and recent arguments by Burkardt [Phys. Rev. D 72 (2005) 094020], we predict that the Boer-Mulders-function h{sub 1} {sup perpendicular} {sup to}, describing correlations of transverse quark spin and intrinsic transverse momentum of quarks, is large and negative for both up and down quarks. (orig.)

  6. Moments of nucleon generalized parton distributions from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrou, C. [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Cyprus Institute, Nicosia (Cyprus). Computation-based Science and Technology Research Center; Carbonell, J.; Harraud, P.A.; Papinutto, M. [UJF/CNRS/IN2P3, Grenoble (France). Lab. de Physique Subatomique et Cosmologie; Constantinou, M.; Kallidonis, C. [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Guichon, P. [CEA-Saclay, Gif-sur-Yvette (France). IRFU-Service de Physique Nucleaire; Jansen, K. [DESY, Zeuthen (Germany). NIC; Korzec, T. [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Humboldt Univ. Berlin (Germany). Inst. fuer Physik

    2011-07-15

    We present results on the lower moments of the nucleon generalized parton distributions within lattice QCD using two dynamical flavors of degenerate twisted mass fermions. Our simulations are performed on lattices with three different values of the lattice spacings, namely a=0.089 fm, a=0.070 fm and a=0.056 fm, allowing the investigation of cut-off effects. The volume dependence is examined using simulations on two lattices of spatial length L=2.1 fm and L=2.8 fm. The simulations span pion masses in the range of 260-470 MeV. Our results are renormalized nonperturbatively and the values are given in the MS scheme at a scale {mu}=2 GeV. They are chirally extrapolated to the physical point in order to compare with experiment. The consequences of these results on the spin carried by the quarks in the nucleon are investigated. (orig.)

  7. A gauge theory of nucleonic interactions by contact

    Science.gov (United States)

    Mazilu, Nicolae; Ioannou, Pavlos D.; Agop, Maricel

    2014-04-01

    A gauge theory of contact is presented, based on the general idea that the local deformation of the nucleon surface at contact should be gauged by the variation of curvature. A contact force is then defined so as to cope with both the variation of curvature and the deformation. This force generalizes the classical definition of surface tension, in that it depends on the mean curvature, but also depends on the variance of the second fundamental form of surface, considered as a statistical variable over the ensemble of contact spots. It turns out that the variance of the second fundamental form does not depend but on the metric of the space of curvature parameters, organized as Riemann space. This result compels us to review the definition of physical surface of a nucleon.

  8. Current status of high energy nucleon-meson transport code

    Energy Technology Data Exchange (ETDEWEB)

    Takada, Hiroshi; Sasa, Toshinobu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Current status of design code of accelerator (NMTC/JAERI code), outline of physical model and evaluation of accuracy of code were reported. To evaluate the nuclear performance of accelerator and strong spallation neutron origin, the nuclear reaction between high energy proton and target nuclide and behaviors of various produced particles are necessary. The nuclear design of spallation neutron system used a calculation code system connected the high energy nucleon{center_dot}meson transport code and the neutron{center_dot}photon transport code. NMTC/JAERI is described by the particle evaporation process under consideration of competition reaction of intranuclear cascade and fission process. Particle transport calculation was carried out for proton, neutron, {pi}- and {mu}-meson. To verify and improve accuracy of high energy nucleon-meson transport code, data of spallation and spallation neutron fragment by the integral experiment were collected. (S.Y.)

  9. Strange quark and the electromagnetic structure of the nucleon: the first results from the G{sup 0} experiment; Contribution du quark etrange a la structure electromagnetique du nucleon: les premiers resultats de l'experience G{sup 0}

    Energy Technology Data Exchange (ETDEWEB)

    Guillon, B

    2005-10-15

    In the framework of the Quantum Chromodynamics (QCD), the nucleon is described as being composed of three valence quarks surrounded by a sea of virtual quark-antiquark pairs and gluons. If the role of this virtual sea in the nucleon properties is inferred to be important, this contribution is still poorly understood. In this context, we study the role of the strange quarks in the nucleon since this is the lightest quark flavor of the sea with no valence contribution. We are determining its contribution to the charge and magnetization distributions in the nucleon via parity violation experiments. The measurement is performed by elastically scattering polarized electrons from nucleon target. A world wide program in which the G0 experiment takes place has been performing for a decade. The G0 experiment and the analysis of the results from its forward angles phase are the topics of this thesis. This document presents the physics case of the strangeness content of the nucleon (mass, spin, impulsion). It describes also the formalism related to the electroweak probe and the form factors, and then the principle of parity violating asymmetry measurement. The G0 experimental setup, which was built and installed in the Hall C of the Jefferson Laboratory (Usa), is detailed. This set-up was designed for the measurement of asymmetries of the order of 10{sup -6} with an overall relative uncertainty better than 10 %, over a momentum transfer range 0.1-1 (GeV/c){sup 2}. The various steps of the data analysis are exposed. They have allowed us to start from measured counting rates to reach parity violating physics asymmetries. This required a careful treatment of the various sources of systematical errors which is discussed extensively. Finally the results from the G0 forward angle measurement, its comparison with others experiments and with theoretical models, are presented. They support a non null strange quark contribution. (author)

  10. Exciting Nucleons in Compton Scattering and Hydrogen-Like Atoms

    OpenAIRE

    Hagelstein, Franziska

    2017-01-01

    This PhD thesis is devoted to the low-energy structure of the nucleon (proton and neutron) as seen through electromagnetic probes, e.g., electron and Compton scattering. The research presented here is based primarily on dispersion theory and chiral effective-field theory. The main motivation is the recent proton radius puzzle, which is the discrepancy between the classic proton charge radius determinations (based on electron-proton scattering and normal hydrogen spectroscopy) and the highly p...

  11. Electromagnetic dissociation of relativistic [sup 28]Si by nucleon emission

    Energy Technology Data Exchange (ETDEWEB)

    Sonnadara, U.J.

    1992-12-01

    A detailed study of the electromagnetic dissociation of [sup 28]Si by nucleon emission at E[sub lab]/A = 14.6 (GeV/nucleon was carried out with [sup 28]Si beams interacting on [sup 208]Pb). [sup 120]Sn. [sup 64]C targets. The measurements apparatus consists of detectors in the target area which measure the energy and charged multiplicity, and a forward spectrometer which measures the position, momentum and energy of the reaction fragments. The exclusive electromagnetic dissociation cross sections for decay channels having multiple nucleons in the final state have been measured which enables the selection of events produced in pure electromagnetic interactions. The measured cross sections agree well with previous measurements obtained for the removal of a few nucleons as well as with measurements on total charge removal cross sections from other experiments. The dependence of the integrated cross sections on the target charge Z[sub T] and the target mass AT confirms that for higher Z targets the excitation is largely electromagnetic. Direct measurements of the excitation energy for the electromagnetic dissociation of [sup 28]Si [yields] p+[sup 27]Al and [sup 28]Si [yields] n+[sup 27]Si have been obtained through a calculation of the invariant mass in kinematically, reconstructed events. The excitation energy spectrum for all targets peak near the isovector giant dipole resonance in [sup 28]Si. These distributions are well reproduced by combining the photon spectrum calculated using the Weizsaecker-Williams approximation with the experimental data on the photonuclear [sup 28]Si([sub [gamma],p])[sup 27]Al and [sup 28]Si([sub [gamma],n])[sup 27]Si. The possibilities of observing double giant dipole resonance excitations in [sup 28]Si have been investigated with cross section measurements as well as with excitation energy reconstruction.

  12. Chiral perturbation theory for nucleon generalized parton distributions

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Manashov, A. [Regensburg Univ. (Germany). Inst. fuer Physik 1 - Theoretische Physik]|[Sankt-Petersburg State Univ. (Russian Federation). Dept. of Theoretical Physics; Schaefer, A. [Regensburg Univ. (Germany). Inst. fuer Physik 1 - Theoretische Physik

    2006-08-15

    We analyze the moments of the isosinglet generalized parton distributions H, E, H, E of the nucleon in one-loop order of heavy-baryon chiral perturbation theory. We discuss in detail the construction of the operators in the effective theory that are required to obtain all corrections to a given order in the chiral power counting. The results will serve to improve the extrapolation of lattice results to the chiral limit. (orig.)

  13. Nucleon spin and quark content at the physical point

    CERN Document Server

    Alexandrou, C; Hadjiyiannakou, K; Kallidonis, Ch; Koutsou, G; Jansen, K; Wiese, Ch; Avilés-Casco, A Vaquero

    2016-01-01

    We present results on the spin and quark content of the nucleon using $N_f=2$ twisted mass clover-improved fermion simulations with a pion mass close to its physical value. We use recently developed methods to obtain accurate results for both connected and disconnected contributions. We provide results for the axial charge, quark and gluon momentum fraction as well as the light, strange and charm $\\sigma$-terms.

  14. Photoproduction of ηπ pairs off nucleons and deuterons

    Energy Technology Data Exchange (ETDEWEB)

    Kaeser, A.; Mueller, F.; Dieterle, M.; Garni, S.; Jaegle, I.; Keshelashvili, I.; Krusche, B.; Maghrbi, Y.; Oberle, M.; Pheron, F.; Rostomyan, T.; Strub, T.; Walford, N.K.; Witthauer, L. [University of Basel, Department of Physics, Basel (Switzerland); Ahrens, J.; Arends, H.J.; Bartolome, P.A.; Ostrick, M.; Otte, P.; Thomas, A. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); Annand, J.R.M.; Hamilton, D.; Howdle, D.; Livingston, K.; MacGregor, I.J.D.; Mancell, J.; McGeorge, J.C.; McNicoll, E.; Robinson, J. [University of Glasgow, SUPA School of Physics and Astronomy, Glasgow (United Kingdom); Bantawa, K.; Manley, D.M. [Kent State University, Kent, OH (United States); Beck, R.; Nikolaev, A.; Schumann, S.; Unverzagt, M. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); University Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Braghieri, A.; Costanza, S.; Mushkarenkov, A.; Pedroni, P. [INFN Sezione di Pavia, Pavia (Italy); Briscoe, W.J.; Marinides, Z. [The George Washington University, Center for Nuclear Studies, Washington (United States); Cherepnya, S.; Fil' kov, L.V. [Lebedev Physical Institute, Moscow (Russian Federation); Downie, E.J. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); University of Glasgow, SUPA School of Physics and Astronomy, Glasgow (United Kingdom); The George Washington University, Center for Nuclear Studies, Washington (United States); Drexler, P.; Metag, V.; Novotny, R.; Thiel, M. [University of Giessen, II. Physikalisches Institut, Giessen (Germany); Fix, A. [Tomsk Polytechnic University, Laboratory of Mathematical Physics, Tomsk (Russian Federation); Glazier, D.I. [University of Glasgow, SUPA School of Physics and Astronomy, Glasgow (United Kingdom); University of Edinburgh, SUPA School of Physics, Edinburgh (United Kingdom); Hornidge, D.; Middleton, D.G. [Mount Allison University, Sackville, New Brunswick (Canada); Huber, G.M. [University of Regina, Regina (Canada); Jude, T.C.; Sikora, M.H.; Watts, D.P. [University of Edinburgh, SUPA School of Physics, Edinburgh (United Kingdom); Kashevarov, V.L. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); Lebedev Physical Institute, Moscow (Russian Federation); Kondratiev, R.; Lisin, V.; Polonski, A. [Institute for Nuclear Research, Moscow (Russian Federation); Korolija, M.; Mekterovic, D.; Micanovic, S.; Supek, I. [Rudjer Boskovic Institute, Zagreb (Croatia); Oussena, B. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); The George Washington University, Center for Nuclear Studies, Washington (United States); Prakhov, S.; Starostin, A. [University of California Los Angeles, Los Angeles, California (United States); Sober, D. [The Catholic University of America, Washington (United States); Werthmueller, D. [University of Basel, Department of Physics, Basel (Switzerland); University of Glasgow, SUPA School of Physics and Astronomy, Glasgow (United Kingdom); Collaboration: The A2 Collaboration

    2016-09-15

    Quasi-free photoproduction of πη-pairs has been investigated from threshold up to incident photon energies of 1.4 GeV, respectively up to photon-nucleon invariant masses up to 1.9 GeV. Total cross sections, angular distributions, invariant-mass distributions of the πη and meson-nucleon pairs, and beam-helicity asymmetries have been measured for the reactions γp → pπ{sup 0}η, γn → nπ{sup 0}η, γp → nπ{sup +}η, and γn → pπ{sup -}η from nucleons bound inside the deuteron. For the γp initial-state data for free protons have also been analyzed. Finally, the total cross sections for quasi-free production of π{sup 0}η pairs from nucleons bound in {sup 3} He nuclei have been investigated in view of final state interaction (FSI) effects. The experiments were performed at the tagged photon beam facility of the Mainz MAMI accelerator using an almost 4π covering electromagnetic calorimeter composed of the Crystal Ball and TAPS detectors. The shapes of all differential cross section data and the asymmetries are very similar for protons and neutrons and agree with the conjecture that the reactions are dominated by the sequential Δ*3/2{sup -} → ηΔ(1232) → πηN decay chain, mainly with Δ(1700)3/2{sup -} and Δ(1940)3/2{sup -}. The ratios of the magnitude of the total cross sections also agree with this assumption. However, the absolute magnitudes of the cross sections are reduced by FSI effects with respect to free proton data. (orig.)

  15. Nucleon spin and quark content at the physical point

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrou, Constantia [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; The Cyprus Institute, Nicosia (Cyprus). Computation-based Science and Technology Research Center; Constantinou, Martha; Hadjiyiannakou, Kyriakos; Kallidonis, Christos; Koutsou, Giannis [The Cyprus Institute, Nicosia (Cyprus). Computation-based Science and Technology Research Center; Jansen, Karl; Wiese, Christian [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Vaquero Aviles-Casco, Alejandro [INFN Sezione di Milano-Bicocca, Milano (Italy)

    2016-12-15

    We present results on the spin and quark content of the nucleon using N{sub f}=2 twisted mass clover-improved fermion simulations with a pion mass close to its physical value. We use recently developed methods to obtain accurate results for both connected and disconnected contributions. We provide results for the axial charge, quark and gluon momentum fraction as well as the light, strange and charm σ-terms.

  16. Obtaining {sigma}{yields}{gamma}{gamma} Width from Nucleon Polarizabilities

    Energy Technology Data Exchange (ETDEWEB)

    Prades, Joaquim [CAFPE and Departamento de Fisica Teorica y del Cosmos, Universidad de Granada, Campus de Fuente Nueva, E-18002 Granada (Spain); Bernabeu, Jose [Departament de Fisica Teorica, IFIC, Universitat de Valencia-CSIC, Apt. de Correus 22085, E-46071 Valencia (Spain)

    2009-01-15

    We propose a new method that fixes the coupling to two photons of the recently found lightest QCD resonance, the {sigma}. This coupling provides crucial information for discriminating the yet unknown nature of this special state. Our method uses available data on the nucleon polarizabilities together with analyticity and unitarity. Taking into account all the uncertainties, our result is {gamma}{sub pole}=1.2{+-}0.4keV.

  17. The Nucleon Axial Form Factor and Staggered Lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Aaron Scott [Chicago U.

    2017-01-01

    The study of neutrino oscillation physics is a major research goal of the worldwide particle physics program over the upcoming decade. Many new experiments are being built to study the properties of neutrinos and to answer questions about the phenomenon of neutrino oscillation. These experiments need precise theoretical cross sections in order to access fundamental neutrino properties. Neutrino oscillation experiments often use large atomic nuclei as scattering targets, which are challenging for theorists to model. Nuclear models rely on free-nucleon amplitudes as inputs. These amplitudes are constrained by scattering experiments with large nuclear targets that rely on the very same nuclear models. The work in this dissertation is the rst step of a new initiative to isolate and compute elementary amplitudes with theoretical calculations to support the neutrino oscillation experimental program. Here, the eort focuses on computing the axial form factor, which is the largest contributor of systematic error in the primary signal measurement process for neutrino oscillation studies, quasielastic scattering. Two approaches are taken. First, neutrino scattering data on a deuterium target are reanalyzed with a model-independent parametrization of the axial form factor to quantify the present uncertainty in the free-nucleon amplitudes. The uncertainties on the free-nucleon cross section are found to be underestimated by about an order of magnitude compared to the ubiquitous dipole model parametrization. The second approach uses lattice QCD to perform a rst-principles computation of the nucleon axial form factor. The Highly Improved Staggered Quark (HISQ) action is employed for both valence and sea quarks. The results presented in this dissertation are computed at physical pion mass for one lattice spacing. This work presents a computation of the axial form factor at zero momentum transfer, and forms the basis for a computation of the axial form factor momentum dependence

  18. Effect of valence nucleons on nuclear binding energy

    Energy Technology Data Exchange (ETDEWEB)

    Angeli, I. (Kossuth Lajos Tudomanyegyetem, Debrecen (HU))

    1991-10-01

    The nucleonic promiscuity factor P = N{sub p}N{sub n}/(N{sub p} + N{sub n}), where N{sub p}(N{sub n}) is the number of valence protons (neutrons) or holes, is shown to be a useful parameter in the description of the mass number dependence of nuclear binding energies. This means that most of the deviation from a smooth mass number dependence is caused by the isoscalar interaction between valence protons and neutrons.

  19. Dispersive micro-solid phase extraction based on self-assembling, ionic liquid-coated magnetic particles for the determination of clofentezine and chlorfenapyr in environmental water samples.

    Science.gov (United States)

    Peng, Bing; Zhang, Jiaheng; Lu, Runhua; Zhang, Sanbing; Zhou, Wenfeng; Gao, Haixiang

    2013-11-21

    Two ionic liquid-coated-Fe3O4 magnetic particles (IL-Fe3O4 MPs) were developed for use in two types of dispersive micro-solid phase extraction (D-μ-SPE) for the high-performance liquid chromatographic analysis of clofentezine and chlorfenapyr in environmental water samples. Self-assembling IL-Fe3O4 MPs were used in D-μ-SPE as adsorbents. Two D-μ-SPE extraction methods, namely, direct dispersive micro-solid phase extraction (d-D-μ-SPE) and in situ solvent formation-based dispersive micro-solid phase extraction (ISF-D-μ-SPE), were proposed, using [C8MIM][PF6] to extract analytes through two pathways. Lower IL doses were required in the extraction process compared with those in other IL-based methods. Fe3O4 MPs can also be recycled and reused after extraction and are thus environmentally friendly. These newly developed methods were demonstrated to be feasible for use in the quantitation of clofentezine and chlorfenapyr at trace levels, with lower limit of detection values ranging from 0.4 to 0.5 ng mL(-1) for d-D-μ-SPE and 0.4 ng mL(-1) for ISF-D-μ-SPE. Finally, relative standard deviations of less than 6.0% were obtained.

  20. Magnetic solid-phase extraction using nanoporous three dimensional graphene hybrid materials for high-capacity enrichment and simultaneous detection of nine bisphenol analogs from water sample.

    Science.gov (United States)

    Wang, Lingling; Zhang, Zhenzhen; Zhang, Jing; Zhang, Lei

    2016-09-09

    The synthesis of a magnetic nanoporous three dimensional graphene (3DG)/ZnFe2O4 composite has been achieved. Through formation of graphene hydrogel, ZnFe2O4 magnetic particles was successfully introduced into the nanoporous 3DG, resulting in a magnetic porous carbon material. The morphology, structure, and magnetic behavior of the as-prepared 3DG/ZnFe2O4 were characterized by using the techniques of SEM, XRD, BET, VSM, FTIR, Raman and TGA. The 3DG/ZnFe2O4 has a high specific surface area and super paramagnetism. Its performance was evaluated by the magnetic solid-phase extraction of nine bisphenol analogs (BPs) from water samples followed by HPLC analysis, and showed excellent adsorption capability for the nine target compounds. Under optimized condition, the lower method detection limits (0.05-0.18ngmL(-1)), the higher enrichment factors (800 fold) and good recoveries (95.1-103.8%) with relative standard deviation (RSD) values less than 6.2% were achieved. The results indicated that the developed method based on the use of 3DG/ZnFe2O4 as the magnetic adsorbent has the advantages of convenience and high efficiency, and can be successfully applied to detect the nine BPs in real water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Grafting of allylimidazole and n-vinylcaprolactam as a thermosensitive polymer onto magnetic nano-particles for the extraction and determination of celecoxib in biological samples.

    Science.gov (United States)

    Morovati, Atefeh; Ahmad Panahi, Homayon; Yazdani, Farzaneh

    2016-11-20

    In this research, a novel method is reported for the surface grafting of n-vinylcaprolactam as a thermosensitive agent and allylimidazole with affinity toward celecoxib onto magnetic nano-particles. The grafted nano-particles were characterized by Fourier transform infrared spectroscopy, elemental analysis, and thermogravimetric analysis. The surface morphology was studied using Scanning Electron Microscopy. The resulting grafted nano-particles were used for the determination of trace celecoxib in biological human fluids and pharmaceutical samples. The profile of celecoxib uptake by the modified magnetic nano-particles indicated good accessibility of the active sites in the grafted copolymer. It was found that the adsorption behavior could be fitted by the Langmuir adsorption isotherm model. Solid phase extraction for biological fluids such as urine and serum were investigated. In this study, urine extraction recovery of more than 95% was obtained. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Nucleon structure functions in noncommutative space-time

    Energy Technology Data Exchange (ETDEWEB)

    Rafiei, A.; Rezaei, Z.; Mirjalili, A. [Yazd University, Physics Department, Yazd (Iran, Islamic Republic of)

    2017-05-15

    In the context of noncommutative space-time we investigate the nucleon structure functions which play an important role in identifying the internal structure of nucleons. We use the corrected vertices and employ new vertices that appear in two approaches of noncommutativity and calculate the proton structure functions in terms of the noncommutative tensor θ{sub μν}. To check our results we plot the nucleon structure function (NSF), F{sub 2}(x), and compare it with experimental data and the results from the GRV, GJR and CT10 parametrization models. We show that with the new vertex that arises the noncommutativity correction will lead to a better consistency between theoretical results and experimental data for the NSF. This consistency will be better for small values of the Bjorken variable x. To indicate and confirm the validity of our calculations we also act conversely. We obtain a lower bound for the numerical values of Λ{sub NC} scale which correspond to recent reports. (orig.)

  3. Nucleon resonances in γ p →K*+Λ

    Science.gov (United States)

    Wang, A. C.; Wang, W. L.; Huang, F.; Haberzettl, H.; Nakayama, K.

    2017-09-01

    The high-precision cross section data for the reaction γ p →K*+Λ reported by the CLAS Collaboration at the Thomas Jefferson National Accelerator Facility have been analyzed based on an effective Lagrangian approach in the tree-level approximation. Apart from the t -channel K ,κ ,K* exchanges, the s -channel nucleon (N ) exchange, the u -channel Λ ,Σ ,Σ*(1385 ) exchanges, and the generalized contact term, the contributions from the near-threshold nucleon resonances in the s channel are also taken into account in constructing the reaction amplitude. It is found that to achieve a satisfactory description of the differential cross section data, at least two nucleon resonances should be included. By including the N (2060 ) 5/2 - resonance, which is responsible for the shape of the angular distribution near the K*Λ threshold, and one of the N (2000 ) 5/2 + , N (2040 ) 3/2 +,N (2100 ) 1/2 +,N (2120 ) 3/2 - and N (2190 ) 7/2 - resonances, one can describe the cross section data quite well, with the fitted resonance masses and widths compatible with those advocated by the Particle Data Group. The resulted predictions of the beam, target, and recoil asymmetries are found to be quite different from various fits, indicating the necessity of the spin observable data for γ p →K*+Λ to further pin down the resonance contents and associated parameters in this reaction.

  4. Quantitative Detection of Trace Level Cloxacillin in Food Samples Using Magnetic Molecularly Imprinted Polymer Extraction and Surface-Enhanced Raman Spectroscopy Nanopillars

    DEFF Research Database (Denmark)

    Ashley, Jon; Wu, Kaiyu; Hansen, Mikkel Fougt

    2017-01-01

    the magnetically susceptible characteristics greatly simplified sample handling procedures. Low cost and robust SERS substrates consisting of vertical gold capped silicon nanopillars were fabricated and employed for the detection of cloxacillin. Quantitative SERS was achieved by normalizing signal intensities...... using an internal standard. By coherently combining MMIP extraction and silicon nanopillar-based SERS biosensor, good sensitivity toward cloxacillin was achieved. The detection limit was 7.8 pmol. Cloxacillin recoveries from spiked pig plasma samples were found to be more than 80%....

  5. Parasitic extraction and magnetic analysis for transformers, inductors and igbt bridge busbar with maxwell 2d and maxwell 3d simulation

    Science.gov (United States)

    Zhang, Ning

    This thesis presents the parasitic extraction and magnetic analysis for transformers, inductors, and IGBT bridge busbars with Maxwell 2D and Maxwell 3D simulation. In the first chapter, the magnetic field of a transformer in Maxwell 2D is analyzed. The parasitic capacitance between each winding of the transformer are extracted by Maxwell 2D. According to the actual dimensions, the parasitic capacitances are calculated. The results are verified by comparing with the measurement results from 4395A impedance analyzer. In the second chapter, two CM inductors are simulated in Maxwell 3D. One is the conventional winding inductor, the other one is the proposed one. The magnetic field distributions of different winding directions are analyzed. The analysis is verified by the simulation result. The last chapter introduces a technique to analyze, extract, and measure the parasitic inductance of planar busbars. With this technique, the relationship between self-inductance and mutual-inductance is analyzed. Secondly, a total inductance is calculated based on the developed technique. Thirdly, the current paths and the inductance on a planar busbar are investigated with DC-link capacitors. Furthermore, the analysis of the inductance is addressed. Ansys Q3D simulation and analysis are presented. Finally, the experimental verification is shown by the S-parameter measurement.

  6. Dispersive solid-phase extraction based on magnetic dummy molecularly imprinted microspheres for selective screening of phthalates in plastic bottled beverages.

    Science.gov (United States)

    Qiao, Jindong; Wang, Mingyu; Yan, Hongyuan; Yang, Gengliang

    2014-04-02

    A new magnetic dummy molecularly imprinted dispersive solid-phase extraction (MAG-MIM-dSPE) coupled with gas chromatography-FID was developed for selective determination of phthalates in plastic bottled beverages. The new magnetic dummy molecularly imprinted microspheres (MAG-MIM) using diisononyl phthalate as a template mimic were synthesized by coprecipitation coupled with aqueous suspension polymerization and were successfully applied as the adsorbents for MAG-MIM-dSPE to extract and isolate five phthalates from plastic bottled beverages. Validation experiments showed that the MAG-MIM-dSPE method had good linearity at 0.0040-0.40 μg/mL (0.9991-0.9998), good precision (3.1-6.9%), and high recovery (89.5-101.3%), and limits of detection were obtained in a range of 0.53-1.2 μg/L. The presented MAG-MIM-dSPE method combines the quick separation of magnetic particles, special selectivity of MIM, and high extraction efficiency of dSPE, which could potentially be applied to selective screening of phthalates in beverage products.

  7. Analysis of microcystins using high-performance liquid chromatography and magnetic solid-phase extraction with silica-coated magnetite with cetylpyridinium chloride.

    Science.gov (United States)

    Li, Qiuying; Lian, Lili; Wang, Xiyue; Wang, Runnan; Tian, Yuanyuan; Guo, Xiaoyang; Lou, Dawei

    2017-04-01

    Microcystins (MCs), produced by freshwater cyanobacteria, can be serious water pollutants, so it is important to monitor their concentration in drinking water. We have developed a method for rapid and accurate determination of microcystin levels in environmental water, using magnetic solid-phase extraction and high-performance liquid chromatography with UV detection. The magnetic composite material, which was combined with cetylpyridinium chloride, was prepared by hydrothermal synthesis. The optimal extraction of microcystins in water sample was achieved by optimizing the amount of adsorbent, time of adsorption, ratio of eluting solvent, and volume of eluent. Under the optimal conditions, the limit of detection of MC-LR was 0.001 μg/L, and the limit of quantification was 0.0028 μg/L. The limit of detection of MC-RR was 0.001 μg/L, and the limit of quantification was 0.003 μg/L. These values are far lower than those established by the International Health Organization for the maximum concentration of microcystins in drinking water. The magnetic solid-phase extraction adsorbent used in this method has the advantages of simple preparation, low price, and easy solid-liquid separation, and it can be used for the rapid and sensitive monitoring of trace microcystins in environmental water samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Use of magnetic effervescent tablet-assisted ionic liquid dispersive liquid-liquid microextraction to extract fungicides from environmental waters with the aid of experimental design methodology.

    Science.gov (United States)

    Yang, Miyi; Wu, Xiaoling; Jia, Yuhan; Xi, Xuefei; Yang, Xiaoling; Lu, Runhua; Zhang, Sanbing; Gao, Haixiang; Zhou, Wenfeng

    2016-02-04

    In this work, a novel effervescence-assisted microextraction technique was proposed for the detection of four fungicides. This method combines ionic liquid-based dispersive liquid-liquid microextraction with the magnetic retrieval of the extractant. A magnetic effervescent tablet composed of Fe3O4 magnetic nanoparticles, sodium carbonate, sodium dihydrogen phosphate and 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonimide) was used for extractant dispersion and retrieval. The main factors affecting the extraction efficiency were screened by a Plackett-Burman design and optimized by a central composite design. Under the optimum conditions, good linearity was obtained for all analytes in pure water model and real water samples. Just for the pure water, the recoveries were between 84.6% and 112.8%, the limits of detection were between 0.02 and 0.10 μg L(-1) and the intra-day precision and inter-day precision both are lower than 4.9%. This optimized method was successfully applied in the analysis of four fungicides (azoxystrobin, triazolone, cyprodinil, trifloxystrobin) in environmental water samples and the recoveries ranged between 70.7% and 105%. The procedure promising to be a time-saving, environmentally friendly, and efficient field sampling technique. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Extracted magnetic resonance texture features discriminate between phenotypes and are associated with overall survival in glioblastoma multiforme patients.

    Science.gov (United States)

    Chaddad, Ahmad; Tanougast, Camel

    2016-11-01

    GBM is a markedly heterogeneous brain tumor consisting of three main volumetric phenotypes identifiable on magnetic resonance imaging: necrosis (vN), active tumor (vAT), and edema/invasion (vE). The goal of this study is to identify the three glioblastoma multiforme (GBM) phenotypes using a texture-based gray-level co-occurrence matrix (GLCM) approach and determine whether the texture features of phenotypes are related to patient survival. MR imaging data in 40 GBM patients were analyzed. Phenotypes vN, vAT, and vE were segmented in a preprocessing step using 3D Slicer for rigid registration by T1-weighted imaging and corresponding fluid attenuation inversion recovery images. The GBM phenotypes were segmented using 3D Slicer tools. Texture features were extracted from GLCM of GBM phenotypes. Thereafter, Kruskal-Wallis test was employed to select the significant features. Robust predictive GBM features were identified and underwent numerous classifier analyses to distinguish phenotypes. Kaplan-Meier analysis was also performed to determine the relationship, if any, between phenotype texture features and survival rate. The simulation results showed that the 22 texture features were significant with p value <0.05. GBM phenotype discrimination based on texture features showed the best accuracy, sensitivity, and specificity of 79.31, 91.67, and 98.75 %, respectively. Three texture features derived from active tumor parts: difference entropy, information measure of correlation, and inverse difference were statistically significant in the prediction of survival, with log-rank p values of 0.001, 0.001, and 0.008, respectively. Among 22 features examined, three texture features have the ability to predict overall survival for GBM patients demonstrating the utility of GLCM analyses in both the diagnosis and prognosis of this patient population.

  10. Preparation and Evaluation of Core–Shell Magnetic Molecularly Imprinted Polymers for Solid-Phase Extraction and Determination of Sterigmatocystin in Food

    Directory of Open Access Journals (Sweden)

    Jing-Min Liu

    2017-10-01

    Full Text Available Magnetic molecularly imprinted polymers (MMIPs, combination of outstanding magnetism with specific selective binding capability for target molecules, have proven to be attractive in separation science and bio-applications. Herein, we proposed the core–shell magnetic molecularly imprinted polymers for food analysis, employing the Fe3O4 particles prepared by co-precipitation protocol as the magnetic core and MMIP film onto the silica layer as the recognition and adsorption of target analytes. The obtained MMIPs materials have been fully characterized by scanning electron microscope (SEM, Fourier transform infrared spectrometer (FT-IR, vibrating sample magnetometer (VSM, and re-binding experiments. Under the optimal conditions, the fabricated Fe3O4@MIPs demonstrated fast adsorption equilibrium, a highly improved imprinting capacity, and excellent specificity to target sterigmatocystin (ST, which have been successfully applied as highly efficient solid-phase extraction materials followed by high-performance liquid chromatography (HPLC analysis. The MMIP-based solid phase extraction (SPE method gave linear response in the range of 0.05–5.0 mg·L−1 with a detection limit of 9.1 µg·L−1. Finally, the proposed method was used for the selective isolation and enrichment of ST in food samples with recoveries in the range 80.6–88.7% and the relative standard deviation (RSD <5.6%.

  11. Determination of catecholamines in urine using aminophenylboronic acid functionalized magnetic nanoparticles extraction followed by high-performance liquid chromatography and electrochemical detection.

    Science.gov (United States)

    Jiang, Liwei; Chen, Yibang; Luo, Yanmei; Tan, Yueming; Ma, Ming; Chen, Bo; Xie, Qingji; Luo, Xubiao

    2015-02-01

    A new method was developed for the simultaneous determination of three catecholamines in urine using aminophenylboronic acid functionalized magnetic nanoparticles extraction followed by high-performance liquid chromatography with electrochemical detection. Novel aminophenylboronic acid functionalized magnetic nanoparticles were prepared by multi-step covalent modification, and characterized by transmission electron microscopy, Fourier-transformed infrared spectroscopy, X-ray diffraction, and vibrating sample magnetometry. With the help of the high affinity between the boronate and cis-diol group, the particles were used for the highly selective separation and enrichment of three major catecholamines, norepinephrine, epinephrine, and dopamine. Effects of the pH of the feed solution, the extraction time, the composition of the buffer solution, the amount of the magnetic particles, the elution conditions, and the recycling of aminophenylboronic acid functionalized magnetic nanoparticles were explored. Under the optimized conditions, 13-17-fold enrichment factors were obtained. The linear ranges were 0.01-2.0 μg/mL for the studied analytes. The limits of detection and quantification were in the range of 2.0-7.9 and 6.7-26.3 ng/mL, respectively. The relative recoveries were in the range of 92-108%, with intraday and interday relative standard deviations lower than 6.8%. This method was successfully applied to analysis of catecholamines in real urine. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Determination of the gluon polarisation in the nucleon in the production of hadrons with high transverse momentum at Compass; Determination de la polarisation des gluons dans le nucleon par la production de hadrons a grande impulsion transverse a COMPASS

    Energy Technology Data Exchange (ETDEWEB)

    Procureur, S

    2006-07-15

    The main goal of the COMPASS experiment at CERN is the determination of the gluon polarisation in the nucleon, V. For this, the helicity asymmetry of the photon gluon fusion process is measured, in the scattering of polarized muons on a polarised deuteron target. This process can be tagged by the production of hadrons with high transverse momentum (pT), that allows to get a large statistics. On the other hand, a physical background remains and complicates the extraction of V. This PhD thesis presents different studies performed to optimize the determination of c in this channel. In particular, a study of the alignment of the 200 detection planes is presented, leading to an improvement of the spectrometer resolution. Performances of the 12 Micromegas detectors have also been determined during 2004 run. Then, the asymmetries obtained in the analysis of 2002 to 2004 data are calculated, for various high PT selections: production of 1 or 2 hadrons, at low or high Q2. An optimization of the selection, based on a neural network, has also been developed, and a detailed study of the experimental false asymmetry has been performed. V extraction is then described, based on Monte Carlo simulations (using PYTHIA or LEPTO). For the first time, the asymmetry of the so-called resolved photon processes is estimated. An improvement on the reconstruction of nucleon momentum fraction carried by the gluon is also proposed, by reconstructing pseudo-jets. Finally, small values obtained for GG are discussed, in terms of constraints on the gluon contribution to the nucleon spin. (author)

  13. Development of novel molecularly imprinted magnetic solid-phase extraction materials based on magnetic carbon nanotubes and their application for the determination of gatifloxacin in serum samples coupled with high performance liquid chromatography.

    Science.gov (United States)

    Xiao, Deli; Dramou, Pierre; Xiong, Nanqian; He, Hua; Li, Hui; Yuan, Danhua; Dai, Hao

    2013-01-25

    A novel composite imprinted material, on the basis of magnetic carbon nanotubes (MCNTs)-incorporated layer using gatifloxacin as a template, methacrylic acid as a functional monomer, and ethylene glycol dimethacrylate as a cross-linker, was successfully synthesized by a surface imprinting technique. Adsorption dynamics and a Scatchard adsorption model were employed to evaluate the adsorption process. The results showed that magnetic carbon nanotubes molecularly imprinted polymers (MCNTs@MIP) displayed a rapid dynamic adsorption and a high adsorption capacity of 192.7 μg/mg toward GTFX. Applied MCNTs@MIP as a sorbent, a magnetic solid phase extraction method coupled with high performance liquid chromatography (MSPE-HPLC) was developed for the determination of GTFX in serum samples. The recoveries from 79.1±4.8% to 85.3±4.2% were obtained. MCNTs@MIP can not only be collected and separated fast by external magnetic field but also have high surface-to-volume ratio, outstanding mechanical properties and specific recognition toward template molecule. In addition, the MCNTs@MIP could be regenerated, which could be used for five cycles with lost of less than 7.8% of its recovery on average. These analytical results of serum samples display that the proposed method based on MCNTs@MIP is applicable for fast and selective extraction of therapeutic agents from biological fluids. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. MAGNET

    CERN Multimedia

    B. Curé

    The first phase of the commissioning ended in August by a triggered fast dump at 3T. All parameters were nominal, and the temperature recovery down to 4.5K was carried out in two days by the cryogenics. In September, series of ramps were achieved up to 3 and finally 3.8T, while checking thoroughly the detectors in the forward region, measuring any movement of and around the HF. After the incident of the LHC accelerator on September 19th, corrective actions could be undertaken in the forward region. When all these displacements were fully characterized and repetitive, with no sign of increments in displacement at each field ramp, it was possible to start the CRAFT, Cosmic Run at Four Tesla (which was in fact at 3.8T). The magnet was ramped up to 18.16kA and the 3 week run went smoothly, with only 4 interruptions: due to the VIP visits on 21st October during the LHC inauguration day; a water leak on the cooling demineralized water circuit, about 1 l/min, that triggered a stop of the cooling pumps, and resulte...

  15. MAGNET

    CERN Multimedia

    Benoit Curé

    The cooling down to the nominal temperature of 4.5 K was achieved at the beginning of August, in conjunction with the completion of the installation work of the connection between the power lines and the coil current leads. The temperature gradient on the first exchanger of the cold box is now kept within the nominal range. A leak of lubricant on a gasket of the helium compressor station installed at the surface was observed and several corrective actions were necessary to bring the situation back to normal. The compressor had to be refilled with lubricant and a regeneration of the filters and adsorbers was necessary. The coil cool down was resumed successfully, and the cryogenics is running since then with all parameters being nominal. Preliminary tests of the 20kA coil power supply were done earlier at full current through the discharge lines into the dump resistors, and with the powering busbars from USC5 to UXC5 without the magnet connected. On Monday evening August 25th, at 8pm, the final commissionin...

  16. MAGNET

    CERN Multimedia

    Benoit Curé

    2013-01-01

    Maintenance work and consolidation activities on the magnet cryogenics and its power distribution are progressing according to the schedules. The manufacturing of the two new helium compressor frame units has started. The frame units support the valves, all the sensors and the compressors with their motors. This activity is subcontracted. The final installation and the commissioning at CERN are scheduled for March–April 2014. The overhauls of existing cryogenics equipment (compressors, motors) are in progress. The reassembly of the components shall start in early 2014. The helium drier, to be installed on the high-pressure helium piping, has been ordered and will be delivered in the first trimester of 2014. The power distribution for the helium compressors in SH5 on the 3.3kV network is progressing. The 3.3kV switches, between each compressor and its hot spare compressor, are being installed, together with the power cables for the new compressors. The 3.3kV electrical switchboards in SE5 will ...

  17. RNA extraction from ten year old formalin-fixed paraffin-embedded breast cancer samples: a comparison of column purification and magnetic bead-based technologies

    Directory of Open Access Journals (Sweden)

    Zhang Haiyu

    2007-12-01

    Full Text Available Abstract Background The development of protocols for RNA extraction from paraffin-embedded samples facilitates gene expression studies on archival samples with known clinical outcome. Older samples are particularly valuable because they are associated with longer clinical follow up. RNA extracted from formalin-fixed paraffin-embedded (FFPE tissue is problematic due to chemical modifications and continued degradation over time. We compared quantity and quality of RNA extracted by four different protocols from 14 ten year old and 14 recently archived (three to ten months old FFPE breast cancer tissues. Using three spin column purification-based protocols and one magnetic bead-based protocol, total RNA was extracted in triplicate, generating 336 RNA extraction experiments. RNA fragment size was assayed by reverse transcription-polymerase chain reaction (RT-PCR for the housekeeping gene glucose-6-phosphate dehydrogenase (G6PD, testing primer sets designed to target RNA fragment sizes of 67 bp, 151 bp, and 242 bp. Results Biologically useful RNA (minimum RNA integrity number, RIN, 1.4 was extracted in at least one of three attempts of each protocol in 86–100% of older and 100% of recently archived ("months old" samples. Short RNA fragments up to 151 bp were assayable by RT-PCR for G6PD in all ten year old and months old tissues tested, but none of the ten year old and only 43% of months old samples showed amplification if the targeted fragment was 242 bp. Conclusion All protocols extracted RNA from ten year old FFPE samples with a minimum RIN of 1.4. Gene expression of G6PD could be measured in all samples, old and recent, using RT-PCR primers designed for RNA fragments up to 151 bp. RNA quality from ten year old FFPE samples was similar to that extracted from months old samples, but quantity and success rate were generally higher for the months old group. We preferred the magnetic bead-based protocol because of its speed and higher quantity of

  18. Polypyrrole/magnetic nanoparticles composite as an efficient sorbent for dispersive micro-solid-phase extraction of antidepressant drugs from biological fluids.

    Science.gov (United States)

    Asgharinezhad, Ali Akbar; Karami, Sara; Ebrahimzadeh, Homeira; Shekari, Nafiseh; Jalilian, Niloofar

    2015-10-15

    In this study, polypyrrole/magnetic nanoparticles composites in the presence of two different dopants were synthesized with the aid of chemical oxidative polymerization process for dispersive-μ-solid phase extraction (D-μ-SPE). The synthesized magnetic sorbents were characterized by various techniques. The results exhibited that the nanocomposite modified by polypyrrole with sodium perchlorate as a dopant demonstrated higher extraction efficiency for citalopram (CIT) and sertraline (STR) as the model compounds. This nanosorbent in combination with high performance liquid chromatography-UV detection was applied for extraction, preconcentration and determination of CIT and STR in urine and plasma samples. The effect of various parameters on the extraction efficiency including: sample pH, amount of sorbent, sorption time, eluent and its volume, salt content, and elution time were investigated and optimized. The opted conditions were: sample pH, 9.0; sorbent dosage, 10mg; sorption time, 7 min; elution solvent and its volume, 0.06 mol L(-1) HCl in methanol, 120 μL; elution time, 2 min and without addition of salt to the sample. The calibration curves were linear in the concentration range of 1-800 μg L(-1). The limits of detection (LODs) were obtained in the range of 0.2-1.0 μg L(-1) for CIT and 0.3-0.7 μg L(-1) for STR, respectively. The percent of extraction recoveries and relative standard deviations (n=5) were in the range of 93.4-99, 4.8-8.4 for CIT and 94-98.4, 4.3-9.2 for STR, respectively. Finally, the applicability of the method was successfully confirmed by the extraction and determination of CIT and STR in human urine and plasma samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Time Dependent Channel Packet Calculation of Two Nucleon Scattering Matrix Elements

    Science.gov (United States)

    2010-03-01

    CHANNEL PACKET CALCULATION OF TWO NUCLEON SCATTERING MATRIX ELEMENTS DISSERTATION Brian S. Davis, Major, USAF AFIT/DS/ENP/10-M03...CALCULATION OF TWO NUCLEON SCATTERING MATRIX ELEMENTS DISSERTATION Presented to the Faculty Graduate School of Engineering and Management...ENPIlO-M03 TIME DEPENDENT CHANNEL PACKET CALCULATION OF TWO NUCLEON SCATTERING MATRIX ELEMENTS Brian S. Davis, BA, MS Major, USAF Approved: ~ !Y

  20. A facile synthesis of novel three-dimensional magnetic imprinted polymers for rapid extraction of bovine serum albumin in bovine calf serum.

    Science.gov (United States)

    Yan, Liang; Wang, Jing; Lv, Piaopiao; Xie, Dandan; Zhang, Zhaohui

    2017-05-01

    A novel three-dimensional (3D) magnetic imprinted polymer was prepared with bovine serum albumin as the template molecule, dopamine as the functional monomer, and a graphene oxide and carbon nanotube hybrid 3D nanocomposite as the carrier. The preparation conditions for the 3D magnetic molecularly imprinted polymers were optimized. The 3D magnetic molecularly imprinted polymers were characterized in detail by scanning electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. The 3D magnetic molecularly imprinted polymers possessed a fast adsorption rate and excellent adsorption performance toward bovine serum albumin, with a maximum adsorption capacity of 78.12 mg g-1. The extraction conditions, including the washing solvent, the pH of the eluent, and the desorption time, were also optimized. Combined with high-performance liquid chromatography, the 3D magnetic molecularly imprinted polymers were successfully applied to enrich and separate bovine serum albumin from bovine calf serum samples with recoveries of 84.0-94.5%. Graphical Abstract ᅟ.

  1. Magnetic solid phase extraction coupled with desorption corona beam ionization-mass spectrometry for rapid analysis of antidepressants in human body fluids.

    Science.gov (United States)

    Chen, Di; Zheng, Hao-Bo; Huang, Yun-Qing; Hu, Yu-Ning; Yu, Qiong-Wei; Yuan, Bi-Feng; Feng, Yu-Qi

    2015-08-21

    Ambient ionization techniques show good potential in rapid analysis of target compounds. However, a direct application of these ambient ionization techniques for the determination of analytes in a complex matrix is difficult due to the matrix interference and ion suppression. To resolve this problem, here we developed a strategy by coupling magnetic solid phase extraction (MSPE) with desorption corona beam ionization (DCBI)-mass spectrometry (MS). As a proof of concept, the pyrrole-coated Fe3O4 magnetic nanoparticles (Fe3O4@Ppy) were prepared and used for the extraction of antidepressants. After extraction, the Fe3O4@Ppy with trapped antidepressants was then directly subjected to DCBI-MS analysis with the aid of a homemade magnetic glass capillary. As the MSPE process is rapid and the direct DCBI-MS analysis does not need solvent desorption or chromatographic separation processes, the overall analysis can be completed within 3 min. The proposed MSPE-DCBI-MS method was then successfully used to determine antidepressants in human urine and plasma. The calibration curves were obtained in the range of 0.005-0.5 μg mL(-1) for urine and 0.02-1 μg mL(-1) for plasma with reasonable linearity (R(2) > 0.951). The limits of detection of three antidepressants were in the range of 0.2-1 ng mL(-1) for urine and 2-5 ng mL(-1) for plasma. Acceptable reproducibility for rapid analysis was achieved with relative standard deviations less than 19.1% and the relative recoveries were 85.2-118.7%. Taken together, the developed MSPE-DCBI-MS strategy offers a powerful capacity for rapid analysis of target compounds in a complex matrix, which would greatly expand the applications of ambient ionization techniques with plentiful magnetic sorbents.

  2. Covariant nucleon wave function with S, D, and P-state components

    Energy Technology Data Exchange (ETDEWEB)

    Franz Gross, G. Ramalho, M. T. Pena

    2012-05-01

    Expressions for the nucleon wave functions in the covariant spectator theory (CST) are derived. The nucleon is described as a system with a off-mass-shell constituent quark, free to interact with an external probe, and two spectator constituent quarks on their mass shell. Integrating over the internal momentum of the on-mass-shell quark pair allows us to derive an effective nucleon wave function that can be written only in terms of the quark and diquark (quark-pair) variables. The derived nucleon wave function includes contributions from S, P and D-waves.

  3. Constructing Nucleon Operators on a Lattice for Form Factors with High Momentum Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Syritsyn, Sergey [Stony Brook Univ., NY (United States); Gambhir, Arjun S. [College of William and Mary, Williamsburg, VA (United States); Musch, Bernhard U. [Univ. of Regensburg (Germany); Orginos, Konstantinos [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2017-05-01

    We present preliminary results of computing nucleon form factor at high momentum transfer using the 'boosted' or 'momentum' smearing. We use gauge configurations generated with N f = 2 + 1dynamical Wilson-clover fermions and study the connected as well as disconnected contributions to the nucleon form factors. Our initial results indicate that boosted smearing helps to improve the signal for nucleon correlators at high momentum. However, we also find evidence for large excited state contributions, which will likely require variational analysis to isolate the boosted nucleon ground state.

  4. Numerical Exact Ab Initio Four-Nucleon Scattering Calculations: from Dream to Reality

    Science.gov (United States)

    Fonseca, A. C.; Deltuva, A.

    2017-03-01

    In the present manuscript we review the work of the last ten years on the pursuit to obtain numerical exact solutions of the four-nucleon scattering problem using the most advanced force models that fit two nucleon data up to pion production threshold with a χ ^2 per data point approximately one, together with the Coulomb interaction between protons; three- and four-nucleon forces are also included in the framework of a meson exchange potential model where NN couples to NΔ. Failure to describe the world data on four-nucleon scattering observables in the framework of a non relativistic scattering approach falls necessarily on the force models one uses. Four-nucleon observables pose very clear challenges, particular in the low energy region where there are a number of resonances whose position and width needs to be dynamically generated by the nucleon-nucleon (NN) interactions one uses. In addition, our calculations constitute the most advance piece of work where observables for all four-nucleon reactions involving isospin I=0, I=0 coupled to I=1 and isospin I=1 initial states are calculated at energies both below and above breakup threshold. We also present a very extensive comparison between calculated results and data for cross sections and spin observables. Therefore the present work reveals both the shortcomings and successes of some of the present NN force models in describing four-nucleon data and serve as a benchmark for future developments.

  5. Extracting Ocean-Generated Tidal Magnetic Signals from Swarm Data through Satellite Gradiometry

    DEFF Research Database (Denmark)

    Sabaka, Terence J.; Tyler, Robert H.; Olsen, Nils

    2016-01-01

    Ocean-generated magnetic field models of the Principal Lunar, M2, and the Larger Lunar elliptic, N2, semi-diurnal tidal constituents were estimated through a “Comprehensive Inversion" of the first 20.5 months of magnetic measurements from ESA's Swarm satellite constellation mission. While the con...

  6. Three-Nucleon Forces and Triplet Pairing in Neutron Matter

    Science.gov (United States)

    Papakonstantinou, P.; Clark, J. W.

    2017-12-01

    The existence of superfluidity of the neutron component in the core of a neutron star, associated specifically with triplet P-wave pairing, is currently an open question that is central to interpretation of the observed cooling curves and other neutron-star observables. Ab initio theoretical calculations aimed at resolving this issue face unique challenges in the relevant high-density domain, which reaches beyond the saturation density of symmetrical nuclear matter. These issues include uncertainties in the three-nucleon (3N) interaction and in the effects of strong short-range correlations—and more generally of in-medium modification of nucleonic self-energies and interactions. A survey of existing solutions of the gap equations in the triplet channel demonstrates that the net impact on the gap magnitude of 3N forces, coupled channels, and mass renormalization shows extreme variation dependent on specific theoretical inputs, in some cases even pointing to the absence of a triplet gap, thus motivating a detailed analysis of competing effects within a well-controlled model. In the present study, we track the effects of the 3N force and in-medium modifications in the representative case of the ^3P_2 channel, based on the Argonne v_{18} two-nucleon (2N) interaction supplemented by 3N interactions of the Urbana IX family. Sensitivity of the results to the input interaction is clearly demonstrated. We point out consistency issues with respect to the simultaneous treatment of 3N forces and in-medium effects, which warrant further investigation. We consider this pilot study as the first step toward a systematic and comprehensive exploration of coupled-channel ^3P F_2 pairing using a broad range of 2N and 3N interactions from the current generation of refined semi-phenomenological models and models derived from chiral effective field theory.

  7. Three-nucleon forces in exotic open-shell isotopes

    Directory of Open Access Journals (Sweden)

    Somà V.

    2014-03-01

    Full Text Available Advances in the self-consistent Green’s function approach to finite nuclei are discussed, including the implementation of three-nucleon forces and the extension to the Gorkov formalism. We report results on binding energies in the nitrogen and fluorine isotopic chains, as well as spectral functions of 22O. The application to medium-mass open-shell systems is illustrated by separation energy spectra of two argon isotopes, which are compared to one-neutron removal experiments.

  8. Quarks and gluons in the nucleon: Proceedings. Volume 6

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The purpose of the symposium was to discuss the quark and gluon structure of the nucleon as probed experimentally by hard processes with lepton and hadron beams and studied theoretically by perturbative QCD, lattice QCD and effective models on the one hand and to stimulate research activities in the fields related to RHIC and RHIC-SPIN projects on the other hand. There were 18 talks and 2 discussion sessions. About 50, including 5 from abroad participated in the symposium. An excellent summary in the form of 5 most important transparencies and a one-page explanation is included for each of the invited talks.

  9. Photoproduction of vector mesons off nucleons near threshold

    Energy Technology Data Exchange (ETDEWEB)

    Friman, B. [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik; Soyeur, M. [Laboratoire National Saturne, Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France)

    1995-12-31

    A simple meson-exchange model is proposed for the photoproduction of {rho}- and {omega}-mesons off protons near threshold. This model provides a good description of the available data and implies a large {rho}-nucleon interaction in the scalar channel ({sigma}-exchange). This phenomenological interaction is applied to estimate the leading contribution to the self-energy of {rho}-mesons in matter. The implications of our calculation for experimental studies of the {rho}-meson mass in nuclei are discussed. (author). 28 refs.

  10. Quasielastic Scattering from Relativistic Bound Nucleons: Transverse-Longitudinal Response

    Energy Technology Data Exchange (ETDEWEB)

    Udias, J. M. [Instituto de Estructura de la Materia, CSIC Serrano 123, E-28006 Madrid, (Spain); Departamento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid, (Spain); Caballero, J. A. [Instituto de Estructura de la Materia, CSIC Serrano 123, E-28006 Madrid, (Spain); Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, E-41080 Sevilla, (Spain); Moya de Guerra, E. [Instituto de Estructura de la Materia, CSIC Serrano 123, E-28006 Madrid, (Spain); Amaro, J. E. [Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada, (Spain); Donnelly, T. W. [Center for Theoretical Physics, Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    1999-12-27

    Predictions for electron induced proton knockout from p{sub 1/2} and p{sub 3/2} shells in {sup 16}O are presented using various approximations for the relativistic nucleonic current. Results for differential cross section, transverse-longitudinal response (R{sub TL} ), and left-right asymmetry A{sub TL} are compared at |Q{sup 2}|=0.8(GeV/c){sup 2} . We show that there are important dynamical and kinematical relativistic effects which can be tested by experiment. (c) 1999 The American Physical Society.

  11. Nucleon structure functions from lattice operator product expansion

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, A.J.; Somfleth, K.; Young, R.D.; Zanotti, J.M. [Adelaide Univ., SA (Australia). CSSM, Dept. of Physics; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe (Japan); Perlt, H.; Schiller, A. [Leipzig Univ. (Germany). Inst. fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2017-03-15

    Deep-inelastic scattering, in the laboratory and on the lattice, is most instructive for understanding how the nucleon is built from quarks and gluons. The long-term goal is to compute the associated structure functions from first principles. So far this has been limited to model calculations. In this Letter we propose a new method to compute the structure functions directly from the virtual, all-encompassing Compton amplitude, utilizing the operator product expansion. This overcomes issues of renormalization and operator mixing, which so far have hindered lattice calculations of power corrections and higher moments.

  12. Spatial distribution of angular momentum inside the nucleon

    Science.gov (United States)

    Lorcé, Cédric; Mantovani, Luca; Pasquini, Barbara

    2018-01-01

    We discuss in detail the spatial distribution of angular momentum inside the nucleon. We show that the discrepancies between different definitions originate from terms that integrate to zero. Even though these terms can safely be dropped at the integrated level, they have to be taken into account when discussing distributions. Using the scalar diquark model, we illustrate our results and, for the first time, check explicitly that the equivalence between kinetic and canonical orbital angular momentum persists at the level of distributions, as expected in a system without gauge degrees of freedom.

  13. Single pion production in neutrino-nucleon interactions

    Science.gov (United States)

    Kabirnezhad, M.

    2018-01-01

    This work represents an extension of the single pion production model proposed by Rein [Z. Phys. C 35, 43 (1987)., 10.1007/BF01561054]. The model consists of resonant pion production and nonresonant background contributions coming from three Born diagrams in the helicity basis. The new work includes lepton mass effects, and nonresonance interaction is described by five diagrams based on a nonlinear σ model. This work provides a full kinematic description of single pion production in the neutrino-nucleon interactions, including resonant and nonresonant interactions in the helicity basis, in order to study the interference effect.

  14. A Search for Nucleon Decay via $n \\rightarrow \\bar{\

    CERN Document Server

    :,; Hayato, Y; Iida, T; Iyogi, K; Kameda, J; Koshio, Y; Kozuma, Y; Marti, Ll; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Obayashi, Y; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takenaga, Y; Ueno, K; Ueshima, K; Yamada, S; Yokozawa, T; Ishihara, C; Kaji, H; Kajita, T; Kaneyuki, K; Lee, K P; McLachlan, T; Okumura, K; Shimizu, Y; Tanimoto, N; Kearns, E; Litos, M; Raaf, J L; Stone, J L; Sulak, L R; Goldhaber, M; Bays, K; Kropp, W R; Mine, S; Regis, C; Renshaw, A; Smy, M B; Sobel, H W; Ganezer, K S; Hill, J; Keig, W E; Jang, J S; Kim, J Y; Lim, I T; Albert, J B; Scholberg, K; Walter, C W; Wendell, R; Wongjirad, T M; Ishizuka, T; Tasaka, S; Learned, J G; Matsuno, S; Smith, S N; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nishikawa, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Takeuchi, Y; Ikeda, M; Minamino, A; Nakaya, T; Fukuda, Y; Itow, Y; Mitsuka, G; Tanaka, T; Jung, C K; Lopez, G D; Taylor, I; Yanagisawa, C; Ishino, H; Kibayashi, A; Mino, S; Mori, T; Sakuda, M; Toyota, H; Kuno, Y; Yoshida, M; Kim, S B; Yang, B S; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Yokoyama, M; Totsuka, Y; Martens, K; Schuemann, J; Vagins, M R; Chen, S; Heng, Y; Yang, Z; Zhang, H; Kielczewska, D; Mijakowski, P; Connolly, K; Dziomba, M; Thrane, E; Wilkes, R J

    2013-01-01

    We present the results of searches for nucleon decay via bound neutron to antineutrino plus pizero and proton to antineutrino plus piplus using data from a combined 172.8 kiloton-years exposure of Super-Kamiokande-I, -II, and -III. We set lower limits on the partial lifetime for each of these modes. For antineutrino pizero, the partial lifetime is >1.1x10^{33} years; for antineutrino piplus, the partial lifetime is >3.9x10^{32} years at 90% confidence level.

  15. Color fluctuations in the nucleon in high-energy scattering.

    Science.gov (United States)

    Frankfurt, L; Strikman, M; Treleani, D; Weiss, C

    2008-11-14

    We study quantum fluctuations of the nucleon's parton densities by combining QCD factorization for hard processes with the notion of cross section fluctuations in soft diffraction. The fluctuations of the small-x gluon density are related to the ratio of inelastic and elastic vector meson production in ep scattering. A simple dynamical model explains the HERA data and predicts the x and Q2 dependence of the ratio. In pp/p[over ]p scattering, fluctuations enhance multiple hard processes (but cannot explain the Tevatron CDF data), and reduce gap survival in central exclusive diffraction.

  16. Weak production of strange particles off the nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Alam, M. Rafi; Athar, M. Sajjad [Department of Physics, Aligarh Muslim University, Aligarh-202 002 (India); Simo, I. Ruiz [Dipartimento di Fisica, Universitá degli Studi di Trento Via Sommarive 14, Povo (Trento) I-38123 (Italy); Alvarez-Ruso, L.; Vacas, M. J. Vicente [Departamento de Física Teórica and Instituto de Física Corpuscular, Centro Mixto Universidad de Valencia-CSIC, E-46071 Valencia (Spain)

    2015-05-15

    The strange particle production off the nucleon induced by neutrinos and antineutrinos is investigated at low and intermediate energies. We develop a microscopic model based on the SU(3) chiral Lagrangian. The studied mechanisms are the main source of single kaon production for (anti)neutrino energies up to 1.5 GeV. Using this model we have also studied the associated production of kaons and hyperons. The cross sections are large enough to be measured by experiments such as MINERνA, T2K and NOνA.

  17. Application of magnetic solid phase extraction for separation and determination of aflatoxins B ₁ and B₂ in cereal products by high performance liquid chromatography-fluorescence detection.

    Science.gov (United States)

    Hashemi, Mahdi; Taherimaslak, Zohreh; Rashidi, Somayeh

    2014-06-01

    A simple and sensitive method based on the magnetic solid phase extraction with modified magnetic nanoparticles followed by high performance liquid chromatography with fluorescence detection has been developed for extraction and determination of aflatoxins B1 (AFB1) and B2 (AFB2) in cereal products. Magnetic nanoparticle coated with 3-(trimethoxysilyl)-1-propanthiol (TMSPT) and modified with 2-amino-5-mercapto-1,3,4-thiadiazole (AMT) was used as an antibody-free adsorbent. Under the optimal conditions, the calibration curves for AFB1 and AFB2 were linear in the ranges of 0.2-15 μg L(-1) and 0.04-3 μg L(-1), respectively. Detection limit was 0.041 μg L(-1) for AFB1 and 0.013 μg L(-1) for AFB2. The proposed method was successfully applied to the determination of AFB1 and AFB2 in spiked corn and rice samples with an average recovery of 93.5%. The results demonstrated that the developed method is simple, rapid, inexpensive, accurate and remarkably free from interference effects. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Computational-aided design of magnetic ultra-thin dummy molecularly imprinted polymer for selective extraction and determination of morphine from urine by high-performance liquid chromatography.

    Science.gov (United States)

    Xi, Shuangling; Zhang, Kai; Xiao, Deli; He, Hua

    2016-11-18

    In this work, a novel magnetic ultra-thin dummy molecularly imprinted polymer (MMIP) for morphine (MO) was prepared. In order to obtain highly selective recognition cavities, the MMIP has been designed using semi-flexible docking to screen the optimal monomer and its ratio to morphine from six representative monomers. Furthermore, the dummy template was creatively screened by semi-flexible docking method from opioid drugs. The system of dihydrocodeine (DI) as dummy template, methacrylamide (MAC) as founctional monomer, ethyleneglycol dimethacrylate (EGDMA) as crosslinker was chosen for MO imprinting. The morphological and magnetic properties of MMIP were characterized by FT-IR, TEM and VSM. The results suggested that molecularly imprinted polymer (MIP) was synthesized evenly on Fe3O4 surface. The adsorption experiments revealed that MMIP showed better extraction capacity and selectivity toward MO and its analogues than the non-imprinted polymer (NIP). The MMIP possessed adsorption capacity of 14.71mg/g for MO and the imprinting factor was 2.10 at separate adsorption and 1.87 at competitive adsorption. A magnetic molecularly imprinted solid phase extraction coupled with HPLC method (M-MISPE-HPLC) has been established for the analysis of MO in urine sample. The developed method was validated for its linearity (0.038-100mgL-1 R2=0.9937), precision (1.07%-3.72%) and accuracy (83.62%-100.37%). Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Transverse target-spin asymmetry associated with deeply virtual Compton scattering on the proton and a resulting model-dependent constraint on the total angular momentum of quarks in the nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Zhenyu

    2007-02-15

    In this thesis we report on the rst results on the transverse target-spin asymmetry associated with deeply virtual Compton scattering on the proton. It is shown that this asymmetry can provide one of the rare possibilities to access the Generalized Parton Distribution (GPD) E of the nucleon, and thus, through models for E, also to the total angular momentum of u and d quarks in the nucleon. The measurement was performed using the 27.6 GeV positron beam of the HERA storage ring and the transversely polarized hydrogen target of the HERMES experiment at DESY. The two leading azimuthal amplitudes of the asymmetry are extracted from the HERMES 2002-2004 data, corresponding to an integrated luminosity of 65.3 pb.1. By comparing the results obtained at HERMES and theoretical predictions based on a phenomenological model of GPDs, we obtain a model-dependent constraint on the total angular momentum of quarks in the nucleon. (orig.)

  20. Magnetic graphene dispersive solid phase extraction-ultra performance liquid chromatography tandem mass spectrometry for determination of β-agonists in urine.

    Science.gov (United States)

    Wang, Geng Nan; Wu, Ning Peng; He, Xin; Zhang, Hui Cai; Liu, Jing; Wang, Jian Ping

    2017-11-01

    In this study, a magnetic graphene-based dispersive solid phase extraction method was first developed for extraction of β-agonists in urine. During the experiments, the absorbent amount, sample pH, extraction time, elution solution and elution time were optimized respectively. The optimized extraction method was finished within 10min, and showed high enrichment factors for 9 β-agonists (20-26 folds). Furthermore, this absorbent could be reused for at least 60 times. Then this extraction method was combined with ultra performance liquid chromatography triple quadrupole tandem mass spectrometry to determine the 9 drugs in urine. The limits of detection for the 9 drugs were in a range of 0.015-0.023ngmL-1, and the recoveries from the standards fortified blank urine were in a range of 60.2%-109.4%. Therefore, this method could be used as a simple, rapid, sensitive and accurate tool to determine trace level of β-agonists in urine. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Ionic liquid-based dispersive liquid-liquid microextraction combined with functionalized magnetic nanoparticle solid-phase extraction for determination of industrial dyes in water.

    Science.gov (United States)

    Liang, Ning; Hou, Xiaohong; Huang, Peiting; Jiang, Chao; Chen, Lijuan; Zhao, Longshan

    2017-10-23

    N-butyl pyridinium bis((trifluoromethyl)sulfonyl)imide ([Hpy]NTf2) functionalized core/shell magnetic nanoparticles (MNPs, Fe3O4@SiO2@[Hpy]NTf2)) were prepared and applied as an adsorbent for magnetic solid phase extraction (MSPE) of three commonly used industrial dyes including malachite green, crystal violet and methylene blue. Extraction solution was mixed with 100 mg extraction material of Fe3O4@SiO2@[Hpy]NTf2, and 1 mL of acetonitrile was used to elute target analytes for further extraction and purification. [Hpy]NTf2 was used as extraction solution, and 500 μL methanol was selected as dispersive solvent in ionic liquid (IL) dispersive liquid-liquid microextraction (DLLME) method. After sonication for 5 min and centrifugation at 447 g for 10 min, 20 μL of sedimented phase was injected into HPLC-UV system. The limit of detection (LOD) and limit of quantification (LOQ) of current method were 0.03 and 0.16 μg·L(-1), respectively, which indicated the sensitivity was comparable or even superior to other reported methods. The relative recoveries of the target analytes ranged from 86.1% to 100.3% with relative standard deviations between 0.3% and 4.5%. The developed method has been successfully applied to determine the level of three industrial dyes in different water samples.

  2. Determination of trace labile copper in environmental waters by magnetic nanoparticle solid phase extraction and high-performance chelation ion chromatography.

    Science.gov (United States)

    Wei, Z; Sandron, S; Townsend, A T; Nesterenko, P N; Paull, B

    2015-04-01

    Cobalt magnetic nanoparticles surface functionalised with iminodiacetic acid were evaluated as a nano-particulate solid phase extraction absorbent for copper ions (Cu(2+)) from environmental water samples. Using an external magnetic field, the collector nanoparticles could be separated from the aqueous phase, and adsorbed ions simply decomplexed using dilute HNO3. Effects of pH, buffer concentration, sample and sorbent volume, extraction equilibrium time, and interfering ion concentration on extraction efficiency were investigated. Optimal conditions were then applied to the extraction of Cu(2+) ions from natural water samples, prior to their quantitation using high-performance chelation ion chromatography. The limits of detection (LOD) of the combined extraction and chromatographic method were ~0.1 ng ml(-1), based upon a 100-fold preconcentration factor (chromatographic performance; LOD=9.2 ng ml(-1) Cu(2+)), analytical linear range from 20 to 5000 ng mL(-1), and relative standard deviations=4.9% (c=1000 ng ml(-1), n=7). Accuracy and precision of the combined approach was verified using a certified reference standard estuarine water sample (SLEW-2) and comparison of sample determinations with sector field inductively coupled plasma mass spectrometry. Recoveries from the addition of Cu(2+) to impacted estuarine and rain water samples were 103.5% and 108.5%, respectively. Coastal seawater samples, both with and without prior UV irradiation and dissolved organic matter removal were also investigated using the new methodology. The effect of DOM concentration on copper availability was demonstrated. Copyright © 2015. Published by Elsevier B.V.

  3. Extraction of toxic compounds from saliva by magnetic-stirring-assisted micro-solid-phase extraction step followed by headspace-gas chromatography-ion mobility spectrometry.

    Science.gov (United States)

    Criado-García, Laura; Arce, Lourdes

    2016-09-01

    A new sample extraction procedure based on micro-solid-phase extraction (μSPE) using a mixture of sorbents of different polarities (polymeric reversed-phase sorbent HLB, silica-based sorbent C18, and multiwalled carbon nanotubes) was applied to extract benzene, toluene, butyraldehyde, benzaldehyde, and tolualdehyde present in saliva to avoid interference from moisture and matrix components and enhance sensitivity and selectivity of the ion mobility spectrometry (IMS) methodology proposed. The extraction of target analytes from saliva samples by using μSPE were followed by the desorption step carried out in the headspace vials placed in the autosampler of the IMS device. Then, 200 μL of headspace was injected into the GC column coupled to the IMS for its analysis. The method was fully validated in terms of sensitivity, precision, and recovery. The LODs and LOQs obtained, when analytes were dissolved in saliva samples to consider the matrix effect, were within the range of 0.38-0.49 and 1.26-1.66 μg mL(-1), respectively. The relative standard deviations were <3.5 % for retention time and drift time values, which indicate that the method proposed can be applied to determine toxic compounds in saliva samples. Graphical abstract Summary of steps followed in the experimental set up of this work.

  4. Ultrasound-assisted magnetic solid-phase extraction for the determination of some transition metals in Orujo spirit samples by capillary electrophoresis.

    Science.gov (United States)

    Peña Crecente, Rosa M; Lovera, Carlha Gutiérrez; García, Julia Barciela; Latorre, Carlos Herrero; Martín, Sagrario García

    2016-01-01

    Ultrasound-assisted magnetic solid-phase extraction coupled to capillary electrophoresis was optimized for the preconcentration and determination of Zn(II), Cu(II), Mn(II) and Cd(II) as their complexes with 1,10-phenanthroline (Phen). Both pre- and on-capillary complexations were employed to obtain stable metal-Phen complexes. The parameters that have an influence on the electrophoretic separation and the MSPE process were studied and optimized using different experimental designs. Metals were extracted from 10 mL of sample at pH 5 using 3mg of magnetic particles functionalized with carboxylic groups. The metals were eluted as metal-Phen complexes and analyzed by capillary electrophoresis. The method showed low limits of detection for metals 0.49-2.19 μg L(-1), and high preconcentration factors, 39-44, The efficiencies of the extraction method were in the range 77.1-87.5% and the precision (RSD < 10%) and accuracy were between 98.2% and 101.6%. The method was applied to the determination of the aforementioned metals in Galician Orujo spirit samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Rapid determination of endogenous cytokinins in plant samples by combination of magnetic solid phase extraction with hydrophilic interaction chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Liu, Zhao; Cai, Bao-Dong; Feng, Yu-Qi

    2012-04-01

    A 2-acrylamido-2-methyl-1-propanesulfonic acid-co-ethylene glycol dimethacrylate (Fe₃O₄/SiO₂/P(AMPS-co-EGDMA)) copolymer was prepared and used as a magnetic solid phase extraction (MSPE) medium for recovery of endogenous cytokinins (CKs) from plant extracts. This magnetic porous polymer was characterized by electron microscopy, nitrogen sorption experiments, elemental analysis and Fourier-transformed infrared spectroscopy. It was demonstrated to have high extraction capacity toward CKs in plants due to its specificity, surface area and porous structure. Coupled with hydrophilic interaction chromatography-tandem mass spectrometry (HILIC-MS/MS), a rapid, simple, and effective MSPE-HILIC-MS/MS analytical method for the quantitative analysis of endogenous CKs in Oryza sativa (O. sativa) roots was successfully established. Good linearities were obtained for all CKs investigated with correlation coefficients (R²>0.9975. The results showed that LODs (S/N=3) were ranged from 0.18 to 3.65 pg mL⁻¹. Reproducibility of the method was obtained with intra-day and inter-day relative standard deviations (RSDs) less than 16.1% and the recoveries in plant samples ranged from 72.8% to 115.5%. Finally, the MSPE-HILIC-MS/MS method was applied to several plant samples, and the amounts of endogenous CKs in O. sativa roots, leaves and Arabidopsis thaliana (A. thaliana) were successfully determined. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Quantitative Detection of Trace Level Cloxacillin in Food Samples Using Magnetic Molecularly Imprinted Polymer Extraction and Surface-Enhanced Raman Spectroscopy Nanopillars.

    Science.gov (United States)

    Ashley, Jon; Wu, Kaiyu; Hansen, Mikkel Fougt; Schmidt, Michael Stenbæk; Boisen, Anja; Sun, Yi

    2017-11-07

    There is an increasing demand for rapid, sensitive, and low cost analytical methods to routinely screen antibiotic residues in food products. Conventional detection of antibiotics involves sample preparation by liquid-liquid or solid-phase extraction, followed by analysis using liquid chromatography-mass spectrometry (LC-MS), capillary electrophoresis (CE), or gas chromatography (GC). The process is labor-intensive, time-consuming, and expensive. In this study, we developed a new analytical method that combines magnetic molecularly imprinted polymer (MMIP)-based sample preparation with surface-enhanced Raman spectroscopy (SERS)-based detection for quantitative analysis of cloxacillin in pig serum. MMIP microspheres were synthesized using a core-shell technique. The large loading capacity and high selectivity of the MMIP microspheres enabled efficient extraction of cloxacillin, while the magnetically susceptible characteristics greatly simplified sample handling procedures. Low cost and robust SERS substrates consisting of vertical gold capped silicon nanopillars were fabricated and employed for the detection of cloxacillin. Quantitative SERS was achieved by normalizing signal intensities using an internal standard. By coherently combining MMIP extraction and silicon nanopillar-based SERS biosensor, good sensitivity toward cloxacillin was achieved. The detection limit was 7.8 pmol. Cloxacillin recoveries from spiked pig plasma samples were found to be more than 80%.

  7. Magnetic Solid-Phase Extraction Using Fe3O4@SiO2 Magnetic Nanoparticles Followed by UV-Vis Spectrometry for Determination of Paraquat in Plasma and Urine Samples

    Directory of Open Access Journals (Sweden)

    Ou Sha

    2017-01-01

    Full Text Available A rapid and simple method was optimized and validated for the separation and quantification of paraquat, a frequently used herbicide and a leading cause of fatal poisoning worldwide, at trace levels with UV-Vis spectrophotometry in plasma and urine samples by direct magnetic solid-phase extraction. Fe3O4@SiO2 nanoparticles (NPs were used as the magnetic solid-phase extraction agents and the paraquat absorbed on NPs was eluted using NaOH and ascorbic acid. Upon optimization, paraquat could be extracted and concentrated from various samples by 35-fold. The linear range, limit of detection (LOD, correlation coefficient (R, and relative standard deviation (RSD could reach 15.0–400.0 μg/L, 12.2 μg/L, 0.9987, and 0.65% (n=5, c = 40.0 μg/L, respectively. The Fe3O4@SiO2 NPs could be reused up to five times. The method was successfully applied to the determination of paraquat in urine and plasma at different hemoperfusion numbers in a local hospital for the patient of paraquat poisoning. The experiment result could not only enable immediate medical intervention but also benefit patients’ survival.

  8. Bio-dispersive liquid liquid microextraction based on nano rhaminolipid aggregates combined with magnetic solid phase extraction using Fe3O4@PPy magnetic nanoparticles for the determination of methamphetamine in human urine.

    Science.gov (United States)

    Haeri, Seyed Ammar; Abbasi, Shahryar; Sajjadifar, Sami

    2017-09-15

    In the present investigation, extraction and preconcentration of methamphetamine in human urine samples was carried out using a novel bio-dispersive liquid liquid microextraction (Bio-DLLME) technique coupled with magnetic solid phase extraction (MSPE). Bio-DLLME is a kind of microextraction technique based nano-materials which have potential capabilities in many application fields. Bio-DLLME is based on the use of a binary part system consisting of methanol and nano rhaminolipid biosurfactant. Use of this binary mixture is ecologically accepted due to their specificity, biocompatibility and biodegradable nature. The potential of nano rhaminolipid biosurfactant as a biological agent in the extraction of organic compounds has been investigated in recent years. They are able to partition at the oil/water interfaces and reduce the interfacial tension in order to increase solubility of hydrocarbons. The properties of the prepared Fe3O4@PPy magnetic nanoparticles were characterized using Fourier transform infrared spectroscopy and X-ray diffraction methods The influences of the experimental parameters on the quantitative recovery of analyte were investigated. Under optimized conditions, the enrichment factor was 310, the calibration graph was linear in the methamphetamine concentration range from 1 to 60μgL(-1), with a correlation coefficient of 0.9998. The relative standard deviations for six replicate measurements was 5.2%. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Preparation of magnetic graphene/mesoporous silica composites with phenyl-functionalized pore-walls as the restricted access matrix solid phase extraction adsorbent for the rapid extraction of parabens from water-based skin toners.

    Science.gov (United States)

    Feng, Jianan; He, Xinying; Liu, Xiaodan; Sun, Xueni; Li, Yan

    2016-09-23

    In this work, phenyl-functionalized magnetic graphene/mesoporous silica composites (MG-mSiO2-Ph) were prepared and applied as restricted access matrix solid phase extraction (RAM-SPE) adsorbents to determine the parabens in commercially available retail cosmetics. MG-mSiO2-Ph composites were synthesized by a surfactant-mediated co-condensation reaction in which mesoporous silica with phenyl-functionalized pore-walls was coated on a magnetic graphene sheet. The obtained nano-composites were proven to be of sufficient quality for an ideal RAM-SPE adsorbent with a large specific surface area of 369m(2)g(-1), uniform mesopores of 2.8nm, and special phenyl-functionalized pore-walls. Parabens, such as methyl paraben, ethyl paraben and propyl paraben, were extracted from water-based skin toners using one step of the RAM-SPE and were then analysed by a HPLC-DAD system. The SPE conditions were optimized by studying the parameters, such as the adsorbent amount, elution solvent type, adsorption time and desorption time, that influence the extraction efficiency. For each analyte, there were good linearities of approximately 0.10-120μgmL(-1) with determination coefficients (R(2))>0.995. The sensitivity was as low as 0.01-0.025μgmL(-1) for the LOD, and the percent recoveries were 98.37-105.84%. The intra-day and inter-day RSDs were 1.44-6.11% (n=6) and 3.12-11.70% (n=6), respectively. The results indicated that this method with novel RAM-SPE adsorbents is sensitive and convenient. The results also offered an attractive alternative for the extraction and determination of paraben preservatives in a complex matrix, such as cosmetics. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Combined use of high-resolution α-glucosidase inhibition profiling and high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy for investigation of antidiabetic principles in crude plant extracts.

    Science.gov (United States)

    Kongstad, Kenneth T; Özdemir, Ceylan; Barzak, Asmah; Wubshet, Sileshi G; Staerk, Dan

    2015-03-04

    Type 2 diabetes is a metabolic disorder affecting millions of people worldwide, and new drug leads or functional foods containing selective α-glucosidase inhibitors are needed. Crude extract of 24 plants were assessed for α-glucosidase inhibitory activity. Methanol extracts of Cinnamomum zeylanicum bark, Rheum rhabarbarum peel, and Rheum palmatum root and ethyl acetate extracts of C. zeylanicum bark, Allium ascalonicum peel, and R. palmatum root showed IC50 values below 20 μg/mL. Subsequently, high-resolution α-glucosidase profiling was used in combination with high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy for identification of metabolites responsible for the α-glucosidase inhibitory activity. Quercetin (1) and its dimer (2), trimer (3), and tetramer (4) were identified as main α-glucosidase inhibitors in A. ascalonicum peel, whereas (E)-piceatannol 3'-O-β-D-glucopyranoside (5), (E)-rhapontigenin 3'-O-β-D-glucopyranoside (6), (E)-piceatannol (8), and emodin (12) were identified as main α-glucosidase inhibitors in R. palmatum root.

  11. Drift motion of the magnetic monopole of Poljakov-'t Hooft in the air and the ball-lightning phenomenon

    Energy Technology Data Exchange (ETDEWEB)

    Korshunov, V.K. (Korshunov Valentin Konstantinovich, Krupskoy Street 78-A, 614077 PERM-77 (SU))

    1990-08-30

    In this paper by virtue of theoretical investigations of V. Rubakov on nucleons and nuclei decay with monopole-nucleon interaction, a qualitative analysis of the drift motion of the mon in the air is conducted. The physical picture obtained coincided in detail with the descriptions of the ball-lightning, for which reason ball- lightning is considered evidence for the magnetic monopole.

  12. Preparation of a magnetic molecularly imprinted polymer by atom-transfer radical polymerization for the extraction of parabens from fruit juices.

    Science.gov (United States)

    You, Xiaoxiao; Piao, Chungying; Chen, Ligang

    2016-07-01

    A silica-based surface magnetic molecularly imprinted polymer for the selective recognition of parabens was prepared using a facile and general method that combined atom-transfer radical polymerization with surface imprinting technique. The prepared magnetic molecularly imprinted polymer was characterized by transmission electron microscopy, Fourier transform infrared spectrometry and physical property measurement. The isothermal adsorption experiment and kinetics adsorption experiment investigated the adsorption property of magnetic molecularly imprinted polymer to template molecule. The four parabens including methylparaben, ethylparaben, propylparaben, and butylparaben were used to assess the rebinding selectivity. An extraction method, which used magnetic molecularly imprinted polymer as adsorbents coupled with high-performance liquid chromatography for the determination of the four parabens in fruit juice samples was developed. Under the optimal conditions, the limits of detections of the four parabens were 0.028, 0.026, 0.021, and 0.026 mg/L, respectively. The precision expressed as relative standard deviation ranging from 2.6 to 8.9% was obtained. In all three fortified levels, recoveries of parabens were in the range of 72.5-89.4%. The proposed method has been applied to different fruit juice samples including orange juice, grape juice, apple juice and peach juice, and satisfactory results were obtained. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Magnetic Solid-Phase Extraction of N,N-Diethyl-m-Toluamide From Baby Toilet Water Prior to its HPLC-UV Detection.

    Science.gov (United States)

    Ma, Xiaowei; Feng, Fan; Yang, Yang; Dang, Xueping; Huang, Jianlin; Chen, Huaixia

    2017-07-01

    Fe3O4@MIL-100 (MIL, Material Institut Lavoisier) core-shell magnetic microspheres were prepared and applied as the sorbent for the magnetic solid phase extraction (MSPE) of N,N-diethyl-m-toluamide (DEET) in baby toilet water for the first time. The synthesized magnetic metal-organic frameworks were characterized by transmission electron microscope, infrared spectroscopy and thermogravimetric analysis. The functionalized magnetic microparticles showed excellent dispersibility in aqueous solution. The MSPE conditions were investigated in detail. Under the optimized conditions, an MSPE-high performance liquid chromatography method for the determination of DEET was developed. The method was linear in the concentration range from 5 to 500 μg L-1 for DEET in baby toilet water and good linearity (r2 > 0.9998) was obtained for the calibration curve. The limit of detection was 1.5 μg L-1. Both the intra-day and inter-day precisions (relative standard deviations) were <3%. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Temperature measurement of fragment emitting systems in Au+Au 35 MeV/nucleon collisions

    Science.gov (United States)

    Milazzo, P. M.; Vannini, G.; Azzano, M.; Fontana, D.; Margagliotti, G. V.; Mastinu, P. F.; Rui, R.; Tonetto, F.; Colonna, N.; Botvina, A.; Bruno, M.; D'agostino, M.; Fiandri, M. L.; Gramegna, F.; Iori, I.; Moroni, A.; Dinius, J. D.; Gaff, S.; Gelbke, C. K.; Glasmacher, T.; Huang, M. J.; Kunde, G. J.; Lynch, W. G.; Martin, L.; Montoya, C. P.; Xi, H.

    1998-08-01

    We report on the results of experiments performed to investigate the Au+Au 35 MeV/nucleon reaction. The reaction products generated in the disassembly of the unique source formed in central collisions and those coming from the decay of the quasiprojectile in peripheral and midperipheral ones (five different impact parameters) were identified through a careful data selection based on the study of energy and angular distributions. The excitation energies of the fragment sources have been extracted through a calorimetric method and by means of a comparison with model calculations. The nuclear temperatures of these decaying systems have been measured from the relative isotopic abundances and, also for central collisions, from the relative populations of excited states. The temperatures of the quasiprojectile disassembling systems are slowly increasing going towards smaller impact parameter. The relationship between temperature and excitation energy seems to be almost independent of the characteristics of the emitting source. The extracted caloric curve shows a slow monotonic increase with increasing excitation energy. A comparison with data derived from Au fragmentation at much higher incident energies is discussed.

  15. Unveiling the nucleon tensor charge at Jefferson Lab: A study of the SoLID case

    Directory of Open Access Journals (Sweden)

    Zhihong Ye

    2017-04-01

    Full Text Available Future experiments at the Jefferson Lab 12 GeV upgrade, in particular, the Solenoidal Large Intensity Device (SoLID, aim at a very precise data set in the region where the partonic structure of the nucleon is dominated by the valence quarks. One of the main goals is to constrain the quark transversity distributions. We apply recent theoretical advances of the global QCD extraction of the transversity distributions to study the impact of future experimental data from the SoLID experiments. Especially, we develop a simple strategy based on the Hessian matrix analysis that allows one to estimate the uncertainties of the transversity quark distributions and their tensor charges extracted from SoLID data simulation. We find that the SoLID measurements with the proton and the effective neutron targets can improve the precision of the u- and d-quark transversity distributions up to one order of magnitude in the range 0.05

  16. The isovector/isoscalar ratio for the imaginary part of the medium-energy nucleon optical model potential studied by the quantum molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Chiba, Satoshi; Niita, Koji; Fukahori, Tokio; Maruyama, Tomoyuki; Maruyama, Toshiki; Iwamoto, Akira [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-05-01

    Energy dependence of the ratio of the isovector and isoscalar strengths in the imaginary part of the nucleon optical model potential at the medium energy range was extracted from an analysis of proton and neutron induced total reaction cross sections on {sup 11}Li with a theoretical framework called quantum molecular dynamics (QMD). The isovector/isoscalar ratio was found to be about 0.8 at 100 MeV, and decreased almost linearly in log(E) to 0 at several hundred MeV. This result was consistent with an estimate at lower energy, and was also in good accord with the values used by Kozack and Madland for the analysis of nucleon + {sup 208}Pb reactions. (author)

  17. Nucleon charge-exchange reactions at intermediate energy

    Energy Technology Data Exchange (ETDEWEB)

    Alford, W.P. [Western Ontario Univ., London, ON (Canada). Dept. of Physics]|[TRIUMF, Vancouver, BC (Canada); Spicer, B.M. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1997-12-31

    An historical review of the development of ideas pertaining to Gamow-Teller giant resonances is given, and a description of the emergence of techniques for the study of charge exchange reactions - particularly the technical advances which yielded the recent volume of new date. The present status of charge exchange reactions is reviewed and assessed. Evidence is presented from the {sup 14}C(p,n) reaction for the dominance of the spin-isospin component of the nucleon-nucleon interaction in intermediate energy reactions. In (p,n) reactions the Gamow-Teller giant resonance dominates the spectra, with higher multipoles contributing. By contrast, in (n,p) reactions in the heavier nuclei, the Gamow-Teller transitions are substantially Pauli-blocked and the spin dipole resonance dominates, with contributions from higher multipoles. Discussions of the multipole decomposition process, used to obtain from the data the contributions of the different multipoles, and the contributions of the multipoles, are given. 226 refs., 19 figs.

  18. Do nucleons in abnormal-parity states contribute to deformation

    Energy Technology Data Exchange (ETDEWEB)

    Bhatt, K.H. (Department of Physics and Astronomy, University of Mississippi, University, Mississippi 38677 (United States) Joint Institute for Heavy-Ion Research, Holifield Heavy Ion Research Facility, Oak Ridge, Tennessee 37831 (United States)); Nestor, C.W. Jr.; Raman, S. (Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States))

    1992-07-01

    We consider intrinsic states of highly deformed nuclei in the framework of the universal Woods-Saxon model and show that valence nucleons in abnormal-parity high-{ital j} states contribute {similar to}20% to the electric quadrupole moments of these nuclei. Similarly, we show that in the single-shell asymptotic Nilsson model this contribution is {similar to}25% if reasonable effective charges are employed. We discuss, at some length, procedures used to arrive at reasonable effective charges. Both models reproduce the measured {ital B}({ital E}2;0{sub 1}{sup +}{r arrow}2{sub 1}{sup +}) values in the rare-earth and actinide regions without the need for normalization constants. No support is found for the assumption made in the pseudo-SU(3) and the fermion dynamic symmetry models that valence nucleons in abnormal-parity high-{ital j} states do not contribute to deformation. This counterintuitive assumption leads to an underestimate of the {ital B}({ital E}2;0{sub 1}{sup +}{r arrow}2{sub 1}{sup +}) values, which is compensated in these models by the use of appropriate normalization constants. Once the magnitudes are fixed, both models do correctly reproduce the {ital B}({ital E}2) trends.

  19. Cooling of Compact Stars with Nucleon Superfluidity and Quark Superconductivity

    Science.gov (United States)

    Noda, Tsuneo; Hashimoto, Masa-aki; Yasutake, Nobutoshi; Maruyama, Toshiki; Tatsumi, Toshitaka

    We show a cooling scenario of compact stars to satisfy recent observations of compact stars. The central density of compact stars can exceed the nuclear density, and it is considered that many hadronic phases appear at such a density. It is discussed that neutron superfluidity (1S0 for lower density, and 3P2 for higher density) and proton superfluidity/superconductivity (1S0) appears in all compact stars. And some "Exotic" states are considered to appear in compact stars, such as meson condensation, hyperon mixing, deconfinement of quarks and quark colour superconductivity. These exotic states appear at the density region above the threshold densities of each state. We demonstrate the thermal evolution of isolated compact stars, adopting the effects of nucleon superfluidity and quark colour superconductivity. We assume large gap energy (Δ > 10 MeV) for colour superconducting quark phase, and include the effects of nucleon superfluidity with parametrised models. We simulate the cooling history of compact stars, and shows that the heavier star does not always cool faster than lighter one, which is determined by the parameters of neutron 3P2 superfluidity.

  20. First results of the cosmic ray NUCLEON experiment

    Science.gov (United States)

    Atkin, E.; Bulatov, V.; Dorokhov, V.; Gorbunov, N.; Filippov, S.; Grebenyuk, V.; Karmanov, D.; Kovalev, I.; Kudryashov, I.; Kurganov, A.; Merkin, M.; Panov, A.; Podorozhny, D.; Polkov, D.; Porokhovoy, S.; Shumikhin, V.; Sveshnikova, L.; Tkachenko, A.; Tkachev, L.; Turundaevskiy, A.; Vasiliev, O.; Voronin, A.

    2017-07-01

    The NUCLEON experiment was designed to study the chemical composition and energy spectra of galactic cosmic ray nuclei from protons to zinc at energies of ~ 1011-1015 eV per particle. The research was carried out with the NUCLEON scientific equipment installed on the Russian satellite "Resource-P" No. 2 as an additional payload. This article presents the results for the measured nuclei spectra related to the first approximately 250 days of the scientific data collection during 2015 and 2016. The all-particle spectrum and the spectra of p, He, C, O, Ne, Mg, Si and Fe are presented. Some interesting ratios of the spectra are also presented and discussed. The experiment is now in its beginning stage and the data still have a preliminary character, but they already give numerous indications of the existence of various non-canonical phenomena in the physics of cosmic rays, which are expressed in the violation of a simple universal power law of the energy spectra. These features of the data are briefly discussed.

  1. Controlling excited-state contamination in nucleon matrix elements

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Boram; Gupta, Rajan; Bhattacharya, Tanmoy; Engelhardt, Michael; Green, Jeremy; Joó, Bálint; Lin, Huey-Wen; Negele, John; Orginos, Kostas; Pochinsky, Andrew; Richards, David; Syritsyn, Sergey; Winter, Frank

    2016-06-01

    We present a detailed analysis of methods to reduce statistical errors and excited-state contamination in the calculation of matrix elements of quark bilinear operators in nucleon states. All the calculations were done on a 2+1 flavor ensemble with lattices of size $32^3 \\times 64$ generated using the rational hybrid Monte Carlo algorithm at $a=0.081$~fm and with $M_\\pi=312$~MeV. The statistical precision of the data is improved using the all-mode-averaging method. We compare two methods for reducing excited-state contamination: a variational analysis and a two-state fit to data at multiple values of the source-sink separation $t_{\\rm sep}$. We show that both methods can be tuned to significantly reduce excited-state contamination and discuss their relative advantages and cost-effectiveness. A detailed analysis of the size of source smearing used in the calculation of quark propagators and the range of values of $t_{\\rm sep}$ needed to demonstrate convergence of the isovector charges of the nucleon to the $t_{\\rm sep} \\to \\infty $ estimates is presented.

  2. Study of Z boson production in PbPb collisions at nucleon-nucleon centre of mass energy = 2.76 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Chatrchyan, S. [Yerevan Physics Institute (Aremenia); et al.,

    2011-05-01

    A search for Z bosons in the mu^+mu^- decay channel has been performed in PbPb collisions at a nucleon-nucleon centre of mass energy = 2.76 TeV with the CMS detector at the LHC, in a 7.2 inverse microbarn data sample. The number of opposite-sign muon pairs observed in the 60--120 GeV/c^2 invariant mass range is 39, corresponding to a yield per unit of rapidity (y) and per minimum bias event of (33.8 +/- 5.5 (stat) +/- 4.4 (syst)) 10^{-8}, in the |y|<2.0 range. Rapidity, transverse momentum, and centrality dependencies are also measured. The results agree with next-to-leading order QCD calculations, scaled by the number of incoherent nucleon-nucleon collisions.

  3. Planar graphene oxide-based magnetic ionic liquid nanomaterial for extraction of chlorophenols from environmental water samples coupled with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Cai, Mei-Qiang; Su, Jie; Hu, Jian-Qiang; Wang, Qian; Dong, Chun-Ying; Pan, Sheng-Dong; Jin, Mi-Cong

    2016-08-12

    A planar graphene oxide-based magnetic ionic liquid nanomaterial (PGO-MILN) was synthesized. The prepared PGO-MILN was characterized by transmission electronmicroscopy (TEM) and Fourier-transform infrared spectrometry (FTIR). The results of adsorption experiments showed that the PGO-MILN had great adsorption capacity for 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP) and pentachlorophenol (PCP). Based on the adsorption experimental data, a sensitive magnetic method for determination of the five CPs in environmental water samples was developed by an effective magnetic solid-phase extraction (MSPE) procedure coupled with high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The effects of main MSPE parameters including the solution pH, extraction time, desorption time, and volume of desorption solution on the extraction efficiencies had been investigated in detail. The recoveries ranged from 85.3 to 99.3% with correlation coefficients (r) higher than 0.9994 and the linear ranges were between 10 and 500ngL(-1). The limits of detection (LODs) and limits of quantification (LOQs) of the five CPs ranged from 0.2 to 2.6ngL(-1) and 0.6 to 8.7ngL(-1), respectively. The intra- and inter- day relative standard deviations (RSDs) were in the range from 0.6% to 7.4% and from 0.7% to 8.4%, respectively. It was confirmed that the PGO-MILN was a kind of highly effective MSPE materials used for enrichment of trace CPs in the environmental water. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. First report on soapnut extract-mediated synthesis of sulphur-substituted nanoscale NdFeB permanent magnets and their characterization

    Science.gov (United States)

    Jayapala Rao, G. V. S.; Prasad, T. N. V. K. V.; Shameer, Syed; Arun, T.; Purnachandra Rao, M.

    2017-10-01

    Biosynthesis of nanoscale materials has its own advantages over other physical and chemical methods. Using soapnut extract as reducing and stabilizing agent for the synthesis of inorganic nanoscale materials is novel and has not been exploited to its potential so far. Herein, we report for the first time on the effects of sulphur substitution on soapnut extract-mediated synthesis of nanoscale NdFeB (S-NdFeB) permanent magnetic powders (Nd 15%, Fe 77.5%, B 7.5% and S with molar ratios: 0.1, 0.2, 0.3, 0.4, and 0.5). To synthesize, a 10 ml of 10% soapnut extract was added to 90 ml of respective chemical composition and heated to 60 °C for 30 min and aged for 24 h. The dried powder was sintered at 500 °C for 1 h. The characterization of the as-prepared nanoscale S-NdFeB magnetic materials was done using the techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersion spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS for size and zeta potential measurements) and vibrating sample magnetometer (VSM)-hysteresis loop studies. The results revealed that particles were highly stable (with a negative zeta potential of 25.7 mV) with irregular and spherical shape (with measured hydrodynamic diameter 6.7 and 63.5 nm). The tetragonal structures of the formed powders were revealed by XRD micrographs. Hysteresis loop studies clearly indicate the effect of S concentration on the enhanced magnetization of the materials.

  5. Fabrication and evaluation of magnetic activated carbon as adsorbent for ultrasonic assisted magnetic solid phase dispersive extraction of bisphenol A from milk prior to high performance liquid chromatographic analysis with ultraviolet detection.

    Science.gov (United States)

    Filippou, Olga; Deliyanni, Eleni A; Samanidou, Victoria F

    2017-01-06

    In the present study, the impregnation of a micro - meso porous activated carbon with magnetite (Fe3O4) was successfully achieved by sonication and the magnetic activated carbon prepared (Bmi) was evaluated as a new adsorbent for ultrasonic assisted magnetic solid phase dispersive extraction of Bisphenol A (BPA) from cow milk and human breast milk samples, prior to the determination by HPLC with UV detection. The prepared Bmi was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The effect of pH on adsorption, initial concentration, contact time and desorption were studied. The main experimental parameters influencing extraction efficiency of BPA, such as type and amount of the adsorbent, sample amount, type of desorption solvent, time of adsorption and desorption, type of precipitation solvent, were investigated and optimized. Under the optimal extraction conditions the absolute recovery of BPA was 81% and 95% in cow milk and human breast milk samples, respectively. Good linearity was observed in the investigated concentration range of 2.5μgkg(-1)-5000μgkg(-1) (R(2)=0.9997). Limit of detection (LOD) was 0.75μgL(-1), which is in accordance with the specific migration limit (SML) established by the European Union, and limit of quantification (LOQ) was 2.5μgL(-1). Within-day and between-day recoveries ranged from 91.4% to 98.6% and 89.1% to 99.4% respectively and the RSDs were less than 3.7%. Due to the excellent magnetic behavior of Bmi the proposed method was shown to be simple and rapid. Besides these, this method is sensitive, low cost, efficient and environmentally friendly. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Biogenic synthesis of Fe{sub 3}O{sub 4} magnetic nanoparticles using Pisum sativum peels extract and its effect on magnetic and Methyl orange dye degradation studies

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Cheera; Yuvaraja, Gutha; Venkateswarlu, Ponneri, E-mail: ponneri.venkateswarlu@gmail.com

    2017-02-15

    We have been developed facile and ecofriendly method for the synthesis of Fe{sub 3}O{sub 4} magnetic nanoparticles (MNPs) using an aqueous extract of Pisum sativum peels (PS) is used as reducing and capping agent. The as synthesized PS-Fe{sub 3}O{sub 4} MNPs are characterized by diverse techniques such as FTIR, powder XRD, TEM, BET and Raman spectroscopy measurements. The results show that the obtained Fe{sub 3}O{sub 4} nanoparticles exhibits high specific surface area (∼17.6 m{sup 2}/g) and agglomerated spherical in shape with the size range of 20–30 nm. The magnetic properties of PS-Fe{sub 3}O{sub 4} MNPs sample clearly exhibits ferromagnetic nature with a saturation magnetization of 64.2 emu/g. Further, the catalytic properties of PS-Fe{sub 3}O{sub 4} MNPs for degradation of Methyl orange (MO) dye in aqueous solution have been investigated by UV–visible spectroscopy. The results show that PS-Fe{sub 3}O{sub 4} MNPs is an efficient catalyst for degradation of Methyl orange dye than previously reported ones. - Highlights: • PS-Fe{sub 3}O{sub 4} MNPs are synthesized using Pisum sativum peels extract. • PS-Fe{sub 3}O{sub 4} MNPs exhibits high specific surface area 17.6 m{sup 2}/g and ferro magnetic behavior. • PS-Fe{sub 3}O{sub 4} MNPs exhibits good catalyst for degradation of Methyl orange dye.

  7. $\\chi$EFT studies of few-nucleon systems: a status report

    Energy Technology Data Exchange (ETDEWEB)

    Schiavilla, Rocco [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Old Dominion Univ., Norfolk, VA (United States)

    2016-06-01

    A status report on $\\chi$EFT studies of few-nucleon electroweak structure and dynamics is provided, including electromagnetic elastic form factors of few-nucleon systems, the $pp$ weak fusion and muon weak captures on deuteron and $^3$He, and a number of parity-violating processes induced by hadronic weak interactions.

  8. Results and Perspectives on Nucleon Form Factors from Snd and CMD-3

    Science.gov (United States)

    Achasov, M. N.; Akhmetshin, R. R.; Anisenkov, A. V.; Aulchenko, V. M.; Banzarov, V. S.; Barkov, L. M.; Barnyakov, A. Yu.; Bashtovoy, N. S.; Beloborodov, K. I.; Berdyugin, A. V.; Berkaev, D. E.; Bogdanchikov, A. G.; Bondar, A. E.; Botov, A. A.; Bragin, A. V.; Dimova, T. V.; Druzhinin, V. P.; Eidelman, S. I.; Epifanov, D. A.; Epshteyn, L. B.; Erofeev, A. L.; Fedotovich, G. V.; Gayazov, S. E.; Golubev, V. B.; Grebenuk, A. A.; Grevtsov, K. A.; Grigoriev, D. N.; Gromov, E. M.; Ignatov, F. V.; Kardapoltsev, L. V.; Karpov, S. V.; Kazanin, V. F.; Kharlamov, A. G.; Khazin, B. I.; Kirpotin, A. N.; Koop, I. A.; Korol, A. A.; Koshuba, S. V.; Kovalenko, O. A.; Kovrizhin, D. P.; Kozyrev, A. N.; Kozyrev, E. A.; Krokovny, P. P.; Kupich, A. S.; Kuzmenko, A. E.; Kuzmin, A. S.; Logashenko, I. B.; Lukin, P. A.; Lysenko, A. P.; Martin, K. A.; Mikhailov, K. Yu.; Obrazovsky, A. E.; Okhapkin, V. S.; Pakhtusova, E. V.; Perevedentsev, E. A.; Pestov, Yu. N.; Popov, A. S.; Popov, Yu. S.; Razuvaev, G. P.; Rogovsky, Yu. A.; Romanov, A. L.; Ruban, A. A.; Ryskulov, N. M.; Ryzhenenkov, A. E.; Serednyakov, S. I.; Shatunov, P. Yu.; Shatunov, Yu. M.; Shebalin, V. E.; Shemyakin, D. N.; Shtol, D. A.; Shwartz, B. A.; Sibidanov, A. L.; Silagadze, Z. K.; Solodov, E. P.; Surin, I. K.; Talyshev, A. A.; Titov, V. M.; Vasiljev, A. V.; Vorobiov, A. I.; Yudin, Yu. V.; Zemlyansky, I. M.; Zharinov, Yu. M.

    2014-12-01

    During years 2011 and 2012 data taking runs have been carried out at VEPP-2000 e+e- collider to measure the production of the nucleon-antinucleon pairs (p\\bar {p}, n\\bar {n}) near threshold. In this talk the preliminary results on the nucleon timelike electromagnetic form factors (FF) and the |GE/GM| ratio are presented.

  9. Disappearance of flow and the in-medium nucleon-nucleon cross section for {sup 64}Zn+{sup 27}Al collisions at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Zhi-Yong He [Caen Univ., 14 (France). Lab. de Physique Corpusculaire]|[Academia Sinica, Lanzhou, GS (China). Inst. of Modern Physics; Peter, J.; Angelique, J.C.; Bizard, G.; Brou, R.; Cussol, D. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire; Auger, A.; Cabot, C.; Crema, E. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Buta, A. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire]|[Institute of Atomic Physics, Bucharest (Romania)] [and others

    1996-09-01

    Experimental measurement and theoretical comparison of collective flow can give important information about the nuclear equation of state (EOS) and the in-medium nucleon-nucleon cross section. Experimental measurements of {sup 64}Zn+{sup 27}Al collision from 35 to 79 MeV/u with the 4{pi} array MUR=TONNEAU are presented. The results are compared to BUU calculations. (K.A.).

  10. In Situ Synthesis of a Magnetic Graphene Platform for the Extraction of Benzimidazoles from Food Samples and Analysis by High-Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Qianchun Zhang

    2017-01-01

    Full Text Available A novel method was proposed for the determination of five benzimidazoles (oxfendazole, mebendazole, flubendazole, albendazole, and fenbendazole using magnetic graphene (G-Fe3O4. G-Fe3O4 was synthesized via in situ chemical coprecipitation. The properties of G-Fe3O4 were characterized by various instrumental methods. G-Fe3O4 exhibited a great adsorption ability and good stability towards analytes. Various experimental parameters that might affect the extraction efficiency such as the amount of G-Fe3O4, extraction solvent, extraction time, and desorption conditions were evaluated. Under the optimized conditions, a method based on G-Fe3O4 magnetic solid-phase extraction coupled with high-performance liquid chromatography was developed. A good linear response was observed in the concentration range of 0.100–100 μg/L for the five benzimidazoles, with correlation coefficients ranging from 0.9966 to 0.9998. The limits of detection (S/N=3 of the method were between 17.2 and 32.3 ng/L. Trace benzimidazoles in chicken, chicken blood, and chicken liver samples were determined and the concentrations of oxfendazole, mebendazole, flubendazole, and fenbendazole in these samples were 13.0–20.2, 1.62–4.64, 1.94–6.42, and 0.292–1.04 ng/g, respectively. The recovery ranged from 83.0% to 115%, and the relative standard deviations were less than 7.9%. The proposed method was sensitive, reliable, and convenient for the analysis of trace benzimidazoles in food samples.

  11. The two-nucleon system at next-to-next-to-next-to-leading order

    Energy Technology Data Exchange (ETDEWEB)

    Evgeny Epelbaum; Walter Gloeckle; Ulf-G. Meissner

    2005-01-01

    We consider the two-nucleon system at next-to-next-to-next-to-leading order (N{sup 3}LO) in chiral effective field theory. The two--nucleon potential at N{sup 3}LO consists of one-, two- and three-pion exchanges and a set of contact interactions with zero, two and four derivatives. In addition, one has to take into account various isospin--breaking and relativistic corrections. We employ spectral function regularization for the multi--pion exchanges. Within this framework, it is shown that the three-pion exchange contribution is negligibly small. The low--energy constants (LECs) related to pion-nucleon vertices are taken consistently from studies of pion-nucleon scattering in chiral perturbation theory. The total of 26 four--nucleon LECs has been determined by a combined fit to some np and pp phase shifts from the Nijmegen analysis together with the nn scattering length.

  12. Shear viscosity of pionic and nucleonic components from their different possible mesonic and baryonic thermal fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Sabyasachi, E-mail: sabyaphy@gmail.com [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Sao Paulo, SP (Brazil). Instituto de Fisica Teorica

    2015-12-15

    Owing to the Kubo relation, the shear viscosities of pionic and nucleonic components have been evaluated from their corresponding retarded correlators of viscous stress tensor in the static limit, which become non-divergent only for the non-zero thermal widths of the constituent particles. In the real-time thermal field theory, the pion and nucleon thermal widths have respectively been obtained from the pion self-energy for different meson, baryon loops, and the nucleon self-energy for different pion-baryon loops. We have found non-monotonic momentum distributions of pion and nucleon thermal widths, which have been integrated out by their respective Bose-enhanced and Pauli-blocked phase space factors during evaluation of their shear viscosities. The viscosity to entropy density ratio for this mixed gas of pion-nucleon system decreases and approaches its lower bound as the temperature and baryon chemical potential increase within the relevant domain of hadronic matter. (author)

  13. Nonequilibrium distribution functions of nucleons in relativistic nucleus-nucleus collisions

    Directory of Open Access Journals (Sweden)

    D. Anchishkin

    2013-03-01

    Full Text Available The collision smearing of the nucleon momenta about their initial values during relativistic nucleus-nucleus collisions is investigated. To a certain degree, our model belongs to the transport type, and we investigate the evolution of the nucleon system created at a nucleus-nucleus collision. However, we parameterize this development by the number of collisions of every particle during evolution rather than by the time variable. It is assumed that the group of nucleons which leave the system after the same number of collisions can be joined in a particular statistical ensemble. The nucleon nonequilibrium distribution functions are derived which depend on a certain number of collisions of a nucleon before a freeze-out.

  14. Quark structure of the nucleon and angular asymmetry of proton-neutron hard elastic scattering.

    Science.gov (United States)

    Granados, Carlos G; Sargsian, Misak M

    2009-11-20

    We investigate an asymmetry in the angular distribution of hard elastic proton-neutron scattering with respect to the 90 degrees center of mass scattering angle and demonstrate that it's magnitude is related to the helicity-isospin symmetry of the quark wave function of the nucleon. Our estimate of the asymmetry within the quark-interchange model of hard scattering demonstrates that the quark wave function of a nucleon based on the exact SU(6) symmetry predicts an angular asymmetry opposite to that of experimental observations. We found that the quark wave function based on the diquark picture of the nucleon produces a correct asymmetry. Comparison with the data allowed us to show that the vector diquarks contribute around 10% in the nucleon wave function and they are in negative phase relative to the scalar diquarks. These observations are essential in constraining QCD models of a nucleon.

  15. pH recycling aqueous two-phase systems applied in extraction of Maitake β-Glucan and mechanism analysis using low-field nuclear magnetic resonance.

    Science.gov (United States)

    Hou, Huiyun; Cao, Xuejun

    2015-07-31

    In this paper, a recycling aqueous two-phase systems (ATPS) based on two pH-response copolymers PADB and PMDM were used in purification of β-Glucan from Grifola frondosa. The main parameters, such as polymer concentration, type and concentration of salt, extraction temperature and pH, were investigated to optimize partition conditions. The results demonstrated that β-Glucan was extracted into PADB-rich phase, while impurities were extracted into PMDM-rich phase. In this 2.5% PADB/2.5% PMDM ATPS, 7.489 partition coefficient and 96.92% extraction recovery for β-Glucan were obtained in the presence of 30mmol/L KBr, at pH 8.20, 30°C. The phase-forming copolymers could be recycled by adjusting pH, with recoveries of over 96.0%. Furthermore, the partition mechanism of Maitake β-Glucan in PADB/PMDM aqueous two-phase systems was studied. Fourier transform infrared spectra, ForteBio Octet system and low-field nuclear magnetic resonance (LF-NMR) were introduced for elucidating the partition mechanism of β-Glucan. Especially, LF-NMR was firstly used in the mechanism analysis in partition of aqueous two-phase systems. The change of transverse relaxation time (T2) in ATPS could reflect the interaction between polymers and β-Glucan. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Solution of two nucleon systems using vector variables in momentum space - an innovative approach

    Science.gov (United States)

    Veerasamy, Saravanan

    An alternate formalism that uses vector variables to treat the two-body Lippmann-Schwinger equation for realistic nucleon-nucleon potentials in momentum space is discussed in this thesis. The formalism uses the symmetry properties of the nucleon-nucleon potential and expands the nucleon-nucleon potential in terms of six linearly independent spin operators. The alternate formalism discussed in this thesis brings to light the role of time-odd spin operators. The vector variable formalism's treatment of spin degrees of freedom heavily depends on the analytical computation of hundreds of algebraic expression. A mathematical framework and computer algorithms for an automated symbolic reduction of algebraic expressions into scalar functions of vector variables are explained in this thesis. The vector variable formalism requires nucleon-nucleon potentials that are in operator form as input. The configuration space nucleon-nucleon potential Argonne V18 is one such potential that can be used for relativistic energies if it can be computed efficiently in momentum space. This thesis develops an efficient numerical technique using Chebyshev approximation to compute the Argonne V18 potential in momentum-space. The tools discussed in this thesis, the algebraic system and the efficient computation of the Argonne V18 potential in momentum space are tested by computing the binding energy and bound state wavefunctions of the deuteron using the vector variable approach. The results were successful and the first step towards a higher goal of using vector formalism of the three-body Faddeev equations for intermediate and high energies has been made.

  17. Magnetic solid phase extraction of brominated flame retardants and pentachlorophenol from environmental waters with carbon doped Fe{sub 3}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jing [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering and Center of Materials Analysis, Nanjing University, 22 Hankou Road, Nanjing 210093 (China); Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biomedical Materials, College of Chemistry and Materials Science, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023 (China); Li, Jia-yuan; Qiao, Jun-qin [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering and Center of Materials Analysis, Nanjing University, 22 Hankou Road, Nanjing 210093 (China); Cui, Shi-hai [Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biomedical Materials, College of Chemistry and Materials Science, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023 (China); Lian, Hong-zhen, E-mail: hzlian@nju.edu.cn [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering and Center of Materials Analysis, Nanjing University, 22 Hankou Road, Nanjing 210093 (China); Chen, Hong-yuan [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering and Center of Materials Analysis, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)

    2014-12-01

    Graphical abstract: - Highlights: • Magnetic Fe{sub 3}O{sub 4}/C nanospheres were used in MSPE of BFRs and PCP from water samples. • The method shows merits of simpleness, reliableness and environmental friendliness. • The bonding between Fe{sub 3}O{sub 4} and coated organic carbon has been demonstrated in Fe{sub 3}O{sub 4}/C. • The straight influences of synthesis conditions of Fe{sub 3}O{sub 4}/C on MSPE were investigated. • The extraction characteristics of Fe{sub 3}O{sub 4}/C nanoparticles were further elucidated. - Abstract: Carbon doped Fe{sub 3}O{sub 4} nanoparticles (Fe{sub 3}O{sub 4}/C) prepared by a facile hydrothermal reaction of glucose with iron resource have been applied as magnetic solid-phase extraction (MSPE) sorbent, for the first time, to extract trace brominated flame retardants (BFRs) and pentachlorophenol (PCP) from environmental waters. Various MSPE parameters were optimized including amount of Fe{sub 3}O{sub 4}/C nanoparticles, pH of sample solution, enrichment factor of analytes and reusability of Fe{sub 3}O{sub 4}/C sorbent. The reliability of the MSPE method was evaluated by the recoveries of BFRs and PCP in spiked water samples. Good recoveries (80.0–110.0%) were achieved with the relative standard deviations range from 0.3% to 6.8%. In this paper, the extraction characteristics of Fe{sub 3}O{sub 4}/C sorbent were further elucidated. It is found that the adsorption process of Fe{sub 3}O{sub 4}/C to analytes predominates the MSPE efficiency. There is hybrid hydrophobic interaction and hydrogen bonding or dipole–dipole attraction between Fe{sub 3}O{sub 4}/C and analytes. Notably, the chemical components of carbon layer on the surface of Fe{sub 3}O{sub 4} nanoparticles were identified by X-ray photoelectron spectroscopy and thermogravimetry-mass spectrometry, and in consequence the covalent bonds between Fe{sub 3}O{sub 4} and the coated carbon have been observed. In addition, the straight influence of synthesis condition of Fe

  18. Determination of polycyclic aromatic hydrocarbons in coffee and tea samples by magnetic solid-phase extraction coupled with HPLC-FLD.

    Science.gov (United States)

    Shi, Yating; Wu, Hao; Wang, Chaoqiong; Guo, Xiaozhen; Du, Juanli; Du, Liming

    2016-05-15

    This study reports the synthesis of a benign nano-adsorbent based on an ionic liquid of immobilized Fe3O4@3-(Trimethoxysilyl)propyl methacrylate@ionic liquid magnetic nanoparticles (Fe3O4@MPS@IL NPs). This material was applied to the magnetic solid phase extraction of seven heavy molecular weight polycyclic aromatic hydrocarbons (PAHs) from coffee and tea samples for high performance liquid chromatography coupled with fluorescence detection. The effects of various parameters of the analytical method were investigated, including pH, sorbent amount, desorption solvent, desorption volume, and extraction and desorption time. Under the optimized conditions, good linearities were obtained, with correlation coefficients (R(2)) between 0.9987 and 0.9998. The detection limits of the proposed method were in the range of 0.1-10ngL(-1). The spiked recoveries of the seven PAHs in coffee and tea samples ranged from 87.5% to 104.5%, with RSDs of less than 3.7%. In addition, a satisfactory reproducibility was achieved, with intra- and inter-day precisions with RSDs of less than 3.1% and 3.8%, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Selective enrichment and determination of monoamine neurotransmitters by CU(II) immobilized magnetic solid phase extraction coupled with high-performance liquid chromatography-fluorescence detection.

    Science.gov (United States)

    He, Maofang; Wang, Chaozhan; Wei, Yinmao

    2016-01-15

    In this paper, iminodiacetic acid-Cu(II) functionalized Fe3O4@SiO2 magnetic nanoparticles were prepared and used as new adsorbents for magnetic solid phase extraction (MSPE) of six monoamine neurotransmitters (MNTs) from rabbit plasma. The selective enrichment of MNTs at pH 5.0 was motivated by the specific coordination interaction between amino groups of MNTs and the immobilized Cu(II). The employed weak acidic extraction condition avoided the oxidation of MNTs, and thus facilitated operation and ensured higher recoveries. Under optimal conditions, the recoveries of six MNTs from rabbit plasma were in the range of 83.9-109.4%, with RSD of 2.0-10.0%. When coupled the Cu(II) immobilized MSPE with high-performance liquid chromatography-fluorescence detection, the method exhibited relatively lower detection limits than the previously reported methods, and the method was successfully used to determine the endogenous MNTs in rabbit plasma. The proposed method has potential application for the determination of MNTs in biological samples. Also, the utilization of coordination interaction to improve the selectivity might open another way to selectively enrich small alkaloids from complex samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Solid phase extraction of amoxicillin using dibenzo-18-crown-6 modified magnetic-multiwalled carbon nanotubes prior to its spectrophotometric determination.

    Science.gov (United States)

    Ahmadi, Mazaher; Madrakian, Tayyebeh; Afkhami, Abbas

    2016-01-01

    This work reports on a method for selective extraction and sensitive determination of amoxicillin drug (AMX). The method is based on solid phase extraction of AMX by a novel modified magnetic nanoadsorbent prior to spectrophotometric determination of AMX using a procedure based on formation a colored azo-derivative of the investigated drug. The nanoadsorbent has been synthesized by modification of magnetic-multiwalled carbon nanotube with dibenzo-18-crown-6 moieties. The synthesized nanoparticles were characterized using TEM, XRD and FT-IR measurements. At the next step, various factors that could potentially affect adsorption and desorption efficiencies of AMX, have been optimized. The results showed that under the optimized conditions, sensitive and selective determination of the investigated drug in concentration range of 5.0-1000.0 ng mL(-1) with the limit of detection of 3.0 ng mL(-1) was achievable. Furthermore, the real sample analysis (i.e. amoxicillin capsules and human urine samples) results indicated that a reliable promising candidate method has been developed for the determination of AMX in the investigated real samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Magnetic solid-phase extraction based on magnetic multiwalled carbon nanotubes for the simultaneous enantiomeric analysis of five β-blockers in the environmental samples by chiral liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Wang, Zhaokun; Zhang, Xue; Jiang, Shenmeng; Guo, Xingjie

    2018-04-01

    In this work, the magnetic multiwalled carbon nanotubes (Mag-MWCNTs) were prepared by self-assembly method and characterized by scanning electron microscopy, X-ray powder diffraction, energy dispersive X-ray and vibrating sample magnetometer. Then, these synthetic Mag-MWCNTs were used as sorbents to extract five β-blockers (atenolol, metoprolol, esmolol, pindolol and arotinolol) by magnetic solid-phase extraction. The target analytes adsorbed on Mag-MWCNTs were eluted and determined on a chiral α-acid glycoprotein column coupled with a triple quadrupole mass spectrometry. Eventually, the proposed method was applied to the analysis of the enantiomeric composition of the studied β-blockers in three environmental samples, including river water, influent wastewater and effluent wastewater. Method detection and quantification limits for all enantiomers were in the range of 0.50-1.45 and 1.63-3.75ng/L, respectively. Satisfactory recovery (82.9-95.6%), good intra-day precision (RSD 0.4-10.4%) and inter-day precision (RSD 2.9-7.4%) were also obtained. With numerous advantages such as simplicity of operation, rapidity and high enrichment factor, the newly developed method has potential to assess the enantioselectivity of chiral drugs in ecotoxicity and biodegradation processes, which is also a new expanded application of Mag-MWCNTs in the environmental analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Mass distributions in nucleon-induced fission at intermediate energies

    CERN Document Server

    Duijvestijn, M C; Hambsch, F J

    2001-01-01

    Temperature-dependent fission barriers and fission-fragment mass distributions are calculated in the framework of the multimodal random neck-rupture model (MM-RNRM). It is shown how the distinction between the different fission modes disappears at higher excitation energies, due to the melting of shell effects. The fission-fragment mass yield calculations are coupled to the nuclear reaction code ALICE-91, which takes into account the competition between the other reaction channels and fission. With the combination of the temperature-dependent MM-RNRM and ALICE-91 nucleon-induced fission is investigated at energies between 10 and 200 MeV for nuclei varying from Au to Am. (72 refs).

  3. Relativity constraints on the two-nucleon contact potential

    Energy Technology Data Exchange (ETDEWEB)

    Girlanda, Luca [Univ. of Pisa (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Pisa (Italy); Pastore, Saori [Old Dominion Univ., Norfolk, VA (United States); Schiavilla, Rocco [Old Dominion Univ., Norfolk, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Viviani, Michele [Istituto Nazionale di Fisica Nucleare (INFN), Pisa (Italy)

    2010-03-01

    We construct the most general, relativistically invariant, contact Lagrangian at order $Q^2$ in the power counting, $Q$ denoting the low momentum scale. A complete, but non-minimal, set of (contact) interaction terms is identified, which upon non-relativistic reduction generate 2 leading independent operator combinations of order $Q^0$ and 7 sub-leading ones of order $Q^2$---a result derived previously in the heavy-baryon formulation of effective field theories (EFT's). We show that Poincar\\'e covariance of the theory requires that additional terms with fixed coefficients be included, in order to describe the two-nucleon potential in reference frames other than the center-of-mass frame. These terms will contribute in systems with mass number $A>2$, and their impact on EFT calculations of binding energies and scattering observables in these systems should be studied.

  4. Studies of spin-dependent hyperon-nucleon interactions

    Energy Technology Data Exchange (ETDEWEB)

    Nakai, K. [Tokyo Univ. of Science, Dept. of Physics, Noda, Chiba (Japan)

    2003-03-01

    The observation of the LS-effect in {sigma}-hyper nuclear experiments has been explored at KEK-ps(proton synchrotron) to study the {sigma}N interaction through the hyperon -scattering experiments. In this experiment, a newly developed track-imaging detector named SCITIC (SCIntillation Track Image Camera) was used. The results on asymmetries of polarized {sigma}{sup +} and {lambda} hyperon scattering on protons have indicated a large {sigma}{sup +}p LS-interaction in contrast to the small {lambda}p LS-interaction. This experimental result is in accord with the quark-model predictions. The {sigma} hyperons are depolarized due to interaction with nucleons in nuclei, but the {lambda} hyperons suffer little depolarization. The result indicates the weakness of the interaction between s-quark and u-, d-quarks. (Y. Kazumata)

  5. Nucleon parton distributions in a light-front quark model

    Energy Technology Data Exchange (ETDEWEB)

    Gutsche, Thomas [Universitaet Tuebingen, Institut fuer Theoretische Physik, Kepler Center for Astro and Particle Physics, Tuebingen (Germany); Lyubovitskij, Valery E. [Universitaet Tuebingen, Institut fuer Theoretische Physik, Kepler Center for Astro and Particle Physics, Tuebingen (Germany); Tomsk State University, Department of Physics, Tomsk (Russian Federation); Tomsk Polytechnic University, Laboratory of Particle Physics, Mathematical Physics Department, Tomsk (Russian Federation); Universidad Tecnica Federico Santa Maria, Departamento de Fisica y Centro Cientifico Tecnologico de Valparaiso (CCTVal), Valparaiso (Chile); Schmidt, Ivan [Universidad Tecnica Federico Santa Maria, Departamento de Fisica y Centro Cientifico Tecnologico de Valparaiso (CCTVal), Valparaiso (Chile)

    2017-02-15

    Continuing our analysis of parton distributions in the nucleon, we extend our light-front quark model in order to obtain both the helicity-independent and the helicity-dependent parton distributions, analytically matching the results of global fits at the initial scale μ∝ 1 GeV; they also contain the correct Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution. We also calculate the transverse parton, Wigner and Husimi distributions from a unified point of view, using our light-front wave functions and expressing them in terms of the parton distributions q{sub v}(x) and δq{sub v}(x). Our results are very relevant for the current and future program of the COMPASS experiment at SPS (CERN). (orig.)

  6. Time-like nucleon form factor measurements at overline{textbf{P}}textbf{ANDA}

    Science.gov (United States)

    Sudoł, Małgorzata

    2009-11-01

    The electromagnetic probe is an excellent tool to investigate the structure of the nucleon. The nearly 4 π detector PANDA, to be installed on the FAIR accelerator complex at Darmstadt, will allow to make a precise determination of the electromagnetic form factors of the proton in the time-like (TL) region with unprecedented precision. In the framework of the one-photon exchange, the center of mass unpolarized differential cross section of the reaction overline{p} p rightarrow e^+ e^- is a linear combination of the squared moduli of the electric Gp_E and magnetic Gp_M proton form factors. The precise measurement of the angular distribution over almost full angular range then directly gives these quantities. Only two experiments have provided the ratio R = {|Gp_E|/|Gp_M|} but with very large statistical uncertainties. Within PANDA, there is a unique opportunity to measure separately the moduli of these two proton form factors Gp_E and Gp_M in good conditions, up to around q 2 = 14 GeV2.

  7. Hermann Grid's Dark Diagonals Disprove QM's ``Beliefs,'' Reveal Stringy Electron, Nucleons, Stick Figure Constellations

    Science.gov (United States)

    McLeod, Roger David; McLeod, David Matthew

    2011-11-01

    Vision detects electric field amplitude information from spatial Fourier transforms, SFTs, of object space. Optics states: at focal, not image, surfaces, for Hermann, and pincushion, grids. Von B'ek'esy's skin pressure experiments prove brain circuitry interprets focal diffraction patterns as inverse SFTs. This knocks out QM beliefs, enhanced by Schr"odinger's electron assertions. Mc Leods' electron string model, based on a neutrino in chiral embrace with a parallel, magnetically repellant, antineutrino, transversely aligned in continuous pairings along each wave-string's closure. This generalized, in Recife, PE, Brazil, to the three-ring, up quark, down quark, up quark, of our Dumbo Proton, underpass-overpass string. Cut by an antineutrino scissor, and merged with our compressed, neutrino-cut electron, a Mickey Neutron with over- or underpass pairs only, emerges, is unstable, and is of 4/3 e string units length. Dumbo Proton is 5/3 e units; this string theory predicts a Trinitarian Electron, with charge -1/3 e, whatever phase, Standing Wave Up, SWU, Traveling Wave, TW, or Standing Wave Down, SWD. It explains solar neutrino flux factor 3 shortfall. Camcorders capture this electron at gigapower n values. Peruvian Nazcans recorded high energy, composite nucleon trajectories for us, as ``applied optical (VISION) physicists.''

  8. Gamma-ray spectroscopy of neutron-rich actinides after multi-nucleon transfer reactions

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, Andreas; Birkenbach, Benedikt; Reiter, Peter [IKP, Universitaet zu Koeln (Germany); Corradi, Lorenzo [INFN - LNL (Italy); Szilner, Suzana [IRB Zagreb (Croatia); Collaboration: LNL 11.22-Collaboration

    2015-07-01

    Excited states in neutron-rich actinide Th and U nuclei were investigated after multi-nucleon transfer reactions employing the AGATA demonstrator and PRISMA setup at LNL (INFN, Italy). A primary 1 GeV {sup 136}Xe beam hitting a {sup 238}U target was used to produce the nuclei of interest in the actinide region. Beam-like reaction products in the Xe-region were identified and selected by the magnetic spectrometer PRISMA. Hence, fission fragments can be discriminated against surviving nuclei, DANTE-MCPs were installed within the target chamber to exploit kinematic coincidences between the binary reaction products which allows for clean conditions for in-beam γ-ray spectroscopy. Coincident γ-rays from excited states in beam- and target-like particles were measured with the position-sensitive AGATA HPGe detectors. An improved Doppler correction for both beam- and target-like nuclei is based on the novel γ-ray tracking technique. An extension of the ground-state rotational band in {sup 240}U and insights into n-rich Th isotopes were achieved. Based on relative cross-section distributions for various reaction channels, perspectives and limitations for the production of the hard-to-reach neutron-rich isotopes with this experimental method will be presented.

  9. Nitrogen-doped carbon quantum dots as a fluorescence probe combined with magnetic solid-phase extraction purification for analysis of folic acid in human serum.

    Science.gov (United States)

    Wang, Meng; Jiao, Yang; Cheng, Chunsheng; Hua, Jianhao; Yang, Yaling

    2017-12-01

    A novel and sensitive method based on nitrogen-doped carbon quantum dots as a fluorescence probe coupled with magnetic solid-phase extraction (MSPE) purification for analysis of folic acid (FA) in human serum samples has been established for the first time. In the developed system, magnetic nanoparticles coated with hexanoic acid (Fe3O4@C6) were synthesized by a one-step chemical co-precipitation method with good magnetic properties and dispersibility for sample purification, and it is better to be separated from the sample. High fluorescence nitrogen-doped carbon quantum dots (N-CQDs), simply prepared using a one-step hydrothermal method with nitrilotriacetic acid, could be selectively quenched by FA. Based on this phenomenon, a fluorescence assay was proposed for specific determination of FA. Various operational experiment parameters have been studied and optimized in detail. Under the optimum experimental conditions, the detection limit of the proposed method for FA was evaluated to be 0.5 nM (S/N = 3), while the relative standard deviation (RSD) was 1.2% (n = 6). Finally, the proposed method was applied for determination of trace levels of FA from human serum samples and quantitative recoveries were achieved within the range of 95.7-103.5%. All of the results showed that the proposed method had significant application in further research. Graphical abstract Schematic of synthesis of N-CQDs and schematic of suggested mode for analysis of folic acid (FA).

  10. Magnetic covalent triazine framework for rapid extraction of phthalate esters in plastic packaging materials followed by gas chromatography-flame ionization detection.

    Science.gov (United States)

    Yan, Zijun; He, Man; Chen, Beibei; Gui, Bo; Wang, Cheng; Hu, Bin

    2017-11-24

    Covalent triazine frameworks (CTFs), featuring with high surface area, good thermal, chemical and mechanical stability, are good adsorbents in sample pretreatment. Herein, magnetic CTFs/Ni composite was prepared by in situ reduction of nickel ions on CTFs matrix with a solvothermal method. The prepared CTFs/Ni composite exhibited good preparation reproducibility, high chemical stability, and high extraction efficiency for targeted phthalate esters (PAEs) due to π-π interaction and hydrophobic effect. The porous structure of CTFs/Ni composite benefited the fast transfer of target PAEs from aqueous solution to the adsorbents, and the integrated magnetism contributed to the rapid separation of adsorbents from sample and elution solution. Based on it, a novel method of magnetic solid phase extraction (MSPE) combined with gas chromatography-flame ionization detector (GC-FID) was developed for the analysis of PAEs including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di-2-ethylhexl phthalate (DEHP), and di-n-octyl phthalate (DNOP) in plastic packaging materials. Under the optimal experimental conditions, the limits of detection (LODs, S/N=3) for six PAEs were found to be in the range of 0.024-0.085mg/kg. The linear range was 0.32-16mg/kg for DMP, DEP, 0.08-80mg/kg for DBP, 0.16-32mg/kg for BBP, DEHP, and 0.32-32mg/kg for DNOP, respectively. The enrichment factors ranged from 59 to 88-fold (theoretical enrichment factor was 133-fold). The proposed method was successfully applied to the analysis of PAEs in various plastic packaging materials with recoveries in the range of 70.6-119% for the spiked samples. This method is characterized with short operation time, high sensitivity, low consumption of harmful organic solvents and can be extended to the analysis of other trace aromatic compounds. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Determination of fluoroquinolone antibiotics in environmental water samples based on magnetic molecularly imprinted polymer extraction followed by liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chen Ligang; Zhang Xiaopan; Xu Yang [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, Jilin (China); Du Xiaobo; Sun Xin [College of Physics, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Sun Lei; Wang Hui; Zhao Qi; Yu Aimin; Zhang Hanqi [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, Jilin (China); Ding Lan, E-mail: dinglan@jlu.edu.cn [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, Jilin (China)

    2010-03-03

    A simple method based on magnetic separation for selective extraction of fluoroquinolones (FQs) from environmental water samples has been developed using magnetic molecularly imprinted polymer (MMIP) as sorbent. The MMIP has been prepared using ciprofloxacin as template molecule, methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross-linking agent and Fe{sub 3}O{sub 4} magnetite as magnetic component. The polymer has been characterized by scanning electron microscopy, Fourier-transform infrared spectrometry and vibrating sample magnetometry. Various parameters affecting the extraction efficiency were evaluated in order to achieve optimal concentration and reduce non-specific interactions. The analytes desorbed from the polymers were determined by liquid chromatography-tandem mass spectrometry. The matrix effect was evaluated by using different washing solvents for removing interfering compounds from the MMIPs after sample loading. Under the optimal conditions, the linearity of the method obtained is in the range of 20-2000 ng L{sup -1}. The detection limits of FQs are in the range of 3.2-6.2 ng L{sup -1}. The relative standard deviations of intra- and inter-day tests ranging from 2.5 to 7.2% and from 3.6 to 9.1% are obtained. In all three spiked levels (20, 100 and 200 ng L{sup -1}), the recoveries of FQs are in the range of 76.3-94.2%. The proposed method was successfully applied to determine FQs including ciprofloxacin, enrofloxacin, lomefloxacin, levofloxacin, fleroxacin and sparfloxacin in different water samples, such as lake water, river water, primary and final sewage effluent. Ciprofloxacin and fleroxacin were found in primary and final sewage effluent samples with the contents in the range of 26-87 ng L{sup -1}.

  12. Development of novel magnetic solid phase extraction materials based on Fe3O4/SiO2/poly(acrylamide-N,N'-methylene bisacrylamide)-Pluronic L64 composite microspheres and their application to the enrichment of natamycin.

    Science.gov (United States)

    Tian, Miaomiao; Zou, Yongcun; Zhou, Shaoyan; Wang, Tianpeng; Lv, Xueju; Jia, Qiong

    2015-12-15

    Novel magnetic adsorbents based on Fe3O4/SiO2/poly(acrylamide-N,N'-methylene bisacrylamide) magnetic microspheres modified with non-ionic triblock copolymer surfactant were successfully prepared as a magnetic solid phase extraction adsorbent for the determination of trace natamycin in jam samples. The adsorbent was characterized by scanning electron microscopy, transmission electron microscopy, Fourier transformed infrared spectroscopy, vibrating sample magnetometer, and X-ray diffractometer analysis, confirming that Pluronic L64 was effectively functionalized on the magnetic materials. Various experimental parameters affecting the extraction capacity were investigated including adsorbent amount, extraction time, desorption time, sample pH, and ionic strength. For recovery evaluations, the jam samples were spiked at two concentration levels of 100 and 200μgkg(-1) of natamycin and the recovery values were in the range of 78.8-93.4%. The relative standard deviations (RSD) for the recoveries were less than 3.5%. The novel magnetic solid phase extraction method provided several advantages, such as simplicity, low environmental impact, convenient extraction procedure, and short analysis time when used for natamycin analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Magnetic reduced graphene oxide functionalized with β-cyclodextrin as magnetic solid-phase extraction adsorbents for the determination of phytohormones in tomatoes coupled with high performance liquid chromatography.

    Science.gov (United States)

    Li, Na; Chen, Juan; Shi, Yan-Ping

    2016-04-08

    A β-cyclodextrin (β-CD) functionalized magnetic reduced graphene oxide composite (Fe3O4/RGO@β-CD) has been prepared and its application as a selective adsorbent for the determination of the two naphthalene-derived phytohormones (1-naphthalene acetic acid (NAA) and 2-naphthoxyacetic acid (2-NOA)) has been investigated. Magnetic reduced graphene oxide composite (Fe3O4/RGO) was first synthesized via in situ chemical precipitation method and then β-CD was applied to further functionalize the resultant Fe3O4/RGO composite. The as-prepared Fe3O4/RGO@β-CD was characterized by Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). Compared with Fe3O4/RGO, the as-prepared Fe3O4/RGO@β-CD showed better molecular selectivity and higher extraction efficiency for NAA and 2-NOA by dint of the size complementarity brought by the introduction of β-CD. Response surface methodology (RSM), a multivariate experimental design technique, was used to optimize experimental parameters affecting the extraction efficiency in detail. Under the optimal conditions, good performance data was obtained. The calibration curves were linear over the concentration ranging from 2 to 600 ngg(-1) with correlation coefficients (R(2)) between 0.9995 and 0.9997 for all the analytes. The limits of detection (LODs) were 0.67 ngg(-1) for both NAA and 2-NOA. The intra- and inter-day relative standard deviations (RSDs) were less than 6.02% and 7.34%, respectively. The recoveries ranged from 91.45% to 95.89%. Taken together, the proposed method was an efficient pretreatment and enrichment procedure and could be successfully applied for selective extraction and determination of naphthalene-derived phytormones in complex matrices. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. First measurement of the gluon polarisation in the nucleon using D mesons at COMPASS

    CERN Document Server

    von Hodenberg, Martin

    2005-01-01

    The complicated structure of the nucleon has been studied with great success in deep-inelastic lepton-nucleon scattering (DIS) experiments at CERN, SLAC and DESY. As a result the unpolarised structure functions have been measured accurately over a wide kinematic range. From these measurements it is possible to determine the gluon density in the nucleon with good accuracy via a so-called QCD fit. In the case of the spin structure of the nucleon the situation is different. Even after decades of experimental and theoretical efforts it remains to be understood how the spin of the nucleon of 1/2 in units of h-bar is to be accounted for in terms of contributions from the quarks and gluons inside the nucleon. Of particular interest is the question whether the polarised gluon density can explain the unexpected smallness of the quark contribution to the nucleon spin. The QCD fit, which worked well in the unpolarised case, yields a polarised gluon density Delta G which is only badly constrained. This is due to the fact...

  15. Leading order relativistic hyperon-nucleon interactions in chiral effective field theory

    Science.gov (United States)

    Li, Kai-Wen; Ren, Xiu-Lei; Geng, Li-Sheng; Long, Bing-Wei

    2018-01-01

    We apply a recently proposed covariant power counting in nucleon-nucleon interactions to study strangeness S=‑1 {{\\varLambda }}N-{{\\varSigma }}N interactions in chiral effective field theory. At leading order, Lorentz invariance introduces 12 low energy constants, in contrast to the heavy baryon approach, where only five appear. The Kadyshevsky equation is adopted to resum the potential in order to account for the non-perturbative nature of hyperon-nucleon interactions. A fit to the 36 hyperon-nucleon scattering data points yields {χ }2≃ 16, which is comparable with the sophisticated phenomenological models and the next-to-leading order heavy baryon approach. However, one cannot achieve a simultaneous description of the nucleon-nucleon phase shifts and strangeness S=‑1 hyperon-nucleon scattering data at leading order. Supported by the National Natural Science Foundation of China (11375024, 11522539, 11375120), the China Postdoctoral Science Foundation (2016M600845, 2017T100008) and the Fundamental Research Funds for the Central Universities

  16. Optimized Extraction of H– by Three-Electrode Faraday Cup System in Magnetized Sheet Plasma Ion Source

    Directory of Open Access Journals (Sweden)

    M. S. Fernandez

    2003-06-01

    Full Text Available A locally designed rectangular parallelepiped, three-electrode Faraday cup system has been developed.Its design incorporates the capability of simultaneous extraction and deposition of the H– ions on substrates.The device functions to attain prescribed selectivity conditions of extracted ions, with controlled energies,for deposition or adsorption. It has been proven to detect the ions at filter bias voltage of 13.61 V with acurrent density of 5.3 A/m2 that is relatively higher than reported (Abate & Ramos, 2000.

  17. Rapid and high-throughput determination of endogenous cytokinins in Oryza sativa by bare Fe3O4 nanoparticles-based magnetic solid-phase extraction.

    Science.gov (United States)

    Cai, Bao-Dong; Zhu, Jiu-Xia; Gao, Qiang; Luo, Dan; Yuan, Bi-Feng; Feng, Yu-Qi

    2014-05-02

    A rapid method was developed for determination of endogenous cytokinins (CKs) based on magnetic solid-phase extraction (MSPE) followed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). We illustrated the hydrophilic character of bare Fe3O4 nanoparticles that were directly used as a MSPE sorbent for rapid enrichment of endogenous CKs from complex plant extract. To the best of our knowledge, this is the first report of bare Fe3O4 directly used as efficient extraction sorbent to enrich target CKs based on hydrophilic interaction. Under the optimized conditions, a rapid, sensitive and high-throughput method for the determination of 16 CKs was established by combination of MSPE with UPLC-MS/MS. Good linearity was obtained with correlation coefficients (r) from 0.9902 to 0.9998. The limits of detection (LODs) and quantification (LOQs) ranged from 1.2 pg mL(-1) to 391.3 pg mL(-1) and 4.1 pg mL(-1) to 1304.3 pg mL(-1), respectively. 16 CKs could be successfully determined in spiked sample with 80.6-117.3% recoveries and the relative standard deviations (RSDs) were less than 16.6%. Finally, 10 endogenous CKs were successfully quantified in 50mg Oryza sativa sample using the developed MSPE-UPLC-MS/MS method. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. A Novel Magnetic Nano-hybrid as a Sorbent for Solid-phase Extraction-spectrophotometric Determination of Methyl Violet 10B Dye

    Directory of Open Access Journals (Sweden)

    Naser Samadi

    2017-12-01

    Full Text Available In this research, the magnetite polystyrene maleic anhydride (MPSMA was synthesized and structure and morphology characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy techniques. The obtained nano-structured inorganic material was employed as a novel magnetic nanosorbent for separation and pre-concentration of Methyl violet (10B dye from aqueous solutions, which can be spectrophotometrically monitored at λ = 585 nm after pre-concentration by solid phase extraction (SPE. The effect of several parameters including pH of the sample solution, amount of the sorbent, extraction and desorption times, and elution conditions and sample volume were investigated and optimized. UV–Vis spectrophotometer was used for determination of MV (10B concentration after desorption of the dye by nitric acid solution. Under the optimum experimental conditions, the limit of detection and the relative standard deviation were 0.08 µg L–1 and 1.10 %, respectively. The enrichment factor of 200 was achieved and the calibration graph using the presented solid phase extraction system was linear in the range of 0.3 – 1500 µg L–1 with a correlation coefficient of 0.9989. The method was successfully applied to pre-concentration of MV (10B from several textile waste water effluents.

  19. Magnetic form factors of the trinucleons

    Energy Technology Data Exchange (ETDEWEB)

    Schiavilla, R; Pandharipande, V R; Riska, Dan-Olof

    1989-11-01

    The magnetic form factors of 3H and 3He are calculated with the Monte Carlo method from variational ground-state wave functions obtained for the Argonne and Urbana two- and three-nucleon interactions. The electromagnetic current operator contains one- and two-body terms that are constructed so as to satisfy the continuity equation with the two-nucleon potential in the Hamiltonian. The results obtained with the Argonne two-nucleon interaction are in overall agreement with the empirical values. It appears that the remaining theoretical uncertainty, in the calculation of these form factors from a given interaction model, is dominated by that in the electromagnetic form factors of the nucleon. It is found that the isovector magnetic form factors are rather sensitive to the details of the isospin-dependent tensor force, and they are much better reproduced with the Argonne than the Urbana potential. The isoscalar magnetic form factors appear to be sensitive to the spin-orbit interactions, and are better reproduced with the Urbana potential. The Argonne potential has a stronger τ1∙τ2 tensor force, while the Urbana one has a shorter-range spin-orbit interaction.

  20. Three Birds with One Fe3O4 Nanoparticle: Integration of Microwave Digestion, Solid Phase Extraction, and Magnetic Separation for Sensitive Determination of Arsenic and Antimony in Fish.

    Science.gov (United States)

    Jia, Yun; Yu, Huimin; Wu, Li; Hou, Xiandeng; Yang, Lu; Zheng, Chengbin

    2015-06-16

    An environmentally friendly and fast sample treatment approach that integrates accelerated microwave digestion (MWD), solid phase extraction, and magnetic separation into a single step was developed for the determination of arsenic and antimony in fish samples by using Fe3O4 magnetic nanoparticles (MNPs). Compared to conventional microwave digestion, the consumption of HNO3 was reduced significantly to 12.5%, and the digestion time and temperature were substantially decreased to 6 min and 80 °C, respectively. This is largely attributed to Fe3O4 magnetic nanoparticles being a highly effective catalyst for rapid generation of oxidative radicals from H2O2, as well as an excellent absorber of microwave irradiation. Moreover, potential interferences from sample matrices were eliminated because the As and Sb species adsorbed on the nanoparticles were efficiently separated from the digests with a hand-held magnet prior to analysis. Limits of detection for arsenic and antimony were in the range of 0.01-0.06 μg g(-1) and 0.03-0.08 μg g(-1) by using hydride generation atomic fluorescence spectrometry, respectively, and further improved to 0.002-0.005 μg g(-1) and 0.005-0.01 μg g(-1) when inductively coupled plasma mass spectrometry was used as a detector. The precision of replicate measurements (n = 9) was better than 6% by analyzing 0.1 g test sample spiked with 1 μg g(-1) arsenic and antimony. The proposed method was validated by analysis of two certified reference materials (DORM-3 and DORM-4) with good recoveries (90%-106%).