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Sample records for extended skyrme interaction

  1. Neutron Matter Properties Using Skyrme Interaction

    NASA Astrophysics Data System (ADS)

    Mansour, H. M. M.; Guirguis, Jannette W.; Abdelmageed, A. I.; Hager, S. A.

    The purpose of the present work is to extend earlier nuclear matter calculations to study the properties of neutron matter. The binding energy per particle, symmetry energy, single particle potential, effective mass, and magnetic susceptibility are calculated using a modified Skyrme interaction. These are calculated as a function of the Fermi momentum kf in the range 0 < kf < 2 fm-1. Two sets of the interaction parameters are obtained by fitting the interaction parameters using the available information on neutron matter. Relativistic corrections to the order 1/c2 are also calculated. The relativistic corrections are very small and they increase as kf is increased.Translated AbstractDie Eigenschaften von Neutronenmaterie bei Annahme von Skyrme-WechselwirkungDie Arbeit zielt auf die Erweiterung früherer Berechnungen zur Kernmaterie auf die Eigenschaftsbestimmung von Neutronenmaterie. Unter Benutzung einer modifizierten Skyrme-Wechselwirkung werden die Bindungsenergie pro Partikel, die Symmetrieenergie, das Einteilchenpotential, die effektive Masse und die magnetische Suszeptibilität als Funktionen des Fermi-Impulses kf im Intervall 0 < kf < 2 fm-1 berechnet. Zwei angepaßte Parameter werden betrachtet. Die relativistischen Korrekturen werden bis zur Größenordnung 1/c2 berechnet. Sie sind sehr klein, wachsen mit wachsendem kf.

  2. Extended Skyrme equation of state in asymmetric nuclear matter

    NASA Astrophysics Data System (ADS)

    Davesne, D.; Pastore, A.; Navarro, J.

    2016-01-01

    We present a new equation of state for infinite systems (symmetric, asymmetric, and neutron matter) based on an extended Skyrme functional that has been constrained by microscopic Brueckner-Bethe-Goldstone results. The resulting equation of state reproduces the main features of microscopic calculations very accurately and is compatible with recent measurements of two times Solar-mass neutron stars. We provide all necessary analytical expressions to facilitate a quick numerical implementation of quantities of astrophysical interest.

  3. Vibrational excitations and a separable approximation for Skyrme interactions

    SciTech Connect

    Severyukhin, A. P.; Voronov, V. V.; Nguyen Van Giai

    2009-01-28

    Starting from an effective Skyrme interaction we present the finite rank separable approach for the quasiparticle random phase approximation. The approach is generalized to take into account the residual particle-particle interaction. As an illustration of the method properties of the low-lying quadrupole states in the even-even nuclei around {sup 132}Sn are studied.

  4. Extended supersymmetry and BPS solutions in baby Skyrme models

    NASA Astrophysics Data System (ADS)

    Adam, C.; Queiruga, J. M.; Sanchez-Guillen, J.; Wereszczynski, A.

    2013-05-01

    We continue the investigation of supersymmetric extensions of baby Skyrme models in d = 2 + 1 dimensions. In a first step, we show that the CP(1) form of the baby Skyrme model allows for the same N = 1 SUSY extension as its O(3) formulation. Then we construct the N = 1 SUSY extension of the gauged baby Skyrme model, i.e., the baby Skyrme model coupled to Maxwell electrodynamics. In a next step, we investigate the issue of N = 2 SUSY extensions of baby Skyrme models. We find that all gauged and ungauged submodels of the baby Skyrme model which support BPS soliton solutions allow for an N = 2 extension such that the BPS solutions are one-half BPS states (i.e., annihilated by one-half of the SUSY charges). In the course of our investigation, we also derive the general BPS equations for completely general N = 2 supersymmetric field theories of (both gauged and ungauged) chiral superfields, and apply them to the gauged nonlinear sigma model as a further, concrete example.

  5. Self-consistent RPA calculations with Skyrme-type interactions: The skyrme_rpa program

    NASA Astrophysics Data System (ADS)

    Colò, Gianluca; Cao, Ligang; Van Giai, Nguyen; Capelli, Luigi

    2013-01-01

    Random Phase Approximation (RPA) calculations are nowadays an indispensable tool in nuclear physics studies. We present here a complete version implemented with Skyrme-type interactions, with the spherical symmetry assumption, that can be used in cases where the effects of pairing correlations and of deformation can be ignored. The full self-consistency between the Hartree-Fock mean field and the RPA excitations is enforced, and it is numerically controlled by comparison with energy-weighted sum rules. The main limitations are that charge-exchange excitations and transitions involving spin operators are not included in this version. Program summaryProgram title: skyrme_rpa (v 1.00) Catalogue identifier: AENF_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AENF_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 5531 No. of bytes in distributed program, including test data, etc.: 39435 Distribution format: tar.gz Programming language: FORTRAN-90/95; easily downgradable to FORTRAN-77. Computer: PC with Intel Celeron, Intel Pentium, AMD Athlon and Intel Core Duo processors. Operating system: Linux, Windows. RAM: From 4 MBytes to 150 MBytes, depending on the size of the nucleus and of the model space for RPA. Word size: The code is written with a prevalent use of double precision or REAL(8) variables; this assures 15 significant digits. Classification: 17.24. Nature of problem: Systematic observations of excitation properties in finite nuclear systems can lead to improved knowledge of the nuclear matter equation of state as well as a better understanding of the effective interaction in the medium. This is the case of the nuclear giant resonances and low-lying collective excitations, which can be described as small amplitude collective motions in the framework of

  6. New Skyrme interaction with improved spin-isospin properties

    NASA Astrophysics Data System (ADS)

    Roca-Maza, X.; Colò, G.; Sagawa, H.

    2012-09-01

    A correct determination of the spin-isospin properties of the nuclear effective interaction should lead to, among other improvements, an accurate description of the Gamow-Teller resonance (GTR). These nuclear excitations impact on a variety of physical processes: from the response in charge-exchange reactions of nuclei naturally present in the Earth, to the description of the stellar nucleosynthesis and of the pre-supernova explosion core-collapse evolution of massive stars in the Universe. A reliable description of the GTR provides also stringent tests for neutrinoless double-β decay calculations. We present a new Skyrme interaction as accurate as previous forces in the description of finite nuclei and of uniform matter properties around saturation density, and that accounts well for the GTR in 48Ca, 90Zr, and 208Pb, and the isobaric analog resonance and spin dipole resonance in 90Zr and 208Pb.

  7. Second RPA calculations with the Skyrme and Gogny interactions

    NASA Astrophysics Data System (ADS)

    Gambacurta, Danilo; Grasso, Marcella

    2016-07-01

    The Second Random Phase Approximation (SRPA) is a natural extension of RPA where more general excitation operators are introduced. These operators contain, in addition to the one particle-one hole configurations already considered in RPA, also two particle-two hole excitations. Only in the last years, large-scale SRPA calculations have been performed, showing the merits and limits of this approach. In the first part of this paper, we present an overview of recent applications of the SRPA based on the Skyrme and Gogny interactions. Giant resonances in 16O will be studied and their properties discussed by using different models. In particular, we will present the first applications of the SRPA model with the finite-range Gogny interaction, discussing the advantages and drawbacks of using such an interaction in this type of calculations. After that, some more recent results, obtained by using a subtraction procedure to overcome double-counting in the SRPA, will be discussed. We will show that this procedure leads to results that are weakly cutoff dependent and that a strong reduction of the SRPA downwards shift with respect to the RPA spectra is found. Moreover, applying this procedure for the first time in the Gogny-SRPA framework, we will show that this method is able to reduce the anomalous shift found in previous calculations and related to some proton-neutron matrix elements of the residual interaction.

  8. Some properties of (3 + 1) dimensional vortex solutions in the extended CP N Skyrme-Faddeev model

    NASA Astrophysics Data System (ADS)

    Ferreira, L. A.; Klimas, P.; Zakrzewski, W. J.

    2011-12-01

    We look at properties of vortex solutions of the extended CP N SkyrmeFaddeev model. We show that only holomorphic solutions of the CP N model are also solutions of the Skyrme-Faddeev model. As the total energy of these solutions is infinite these solutions should be interpreted as describing time dependent vortices. We describe their dynamics and, in partcular, point out that one of the terms in the energy density is related to the Noether charge of the model.

  9. Kaon-Nucleon systems and their interactions in the Skyrme model

    NASA Astrophysics Data System (ADS)

    Ezoe, Takashi; Hosaka, Atsushi

    2016-08-01

    We study kaon-nucleon systems in the Skyrme model in a method based on the bound state approach of Callan-Klebanov but with the kaon around the physical nucleon of the rotating hedgehog. This corresponds to the variation after projection, reversing the order of semiclassical quantization of 1 /Nc expansion. The method, however, is considered to be suited to the study of weakly interacting kaon-nucleon systems including loosely K ¯N bound states such as Λ (1405 ). We have found a bound state with binding energy of order 10 MeV, consistent with the observed state. We also discuss the K ¯N interaction and find that it consists of an attraction in the middle range and a repulsion in the short range.

  10. Large scale calculations for cluster structure of light nuclei with Skyrme interaction

    NASA Astrophysics Data System (ADS)

    Fukuoka, Y.; Funaki, Y.; Nakatsukasa, T.; Yabana, K.

    2013-04-01

    We present a computational approach to describe structure of light nuclei including cluster states. Apart from the use of an empirical nuclear force, Skyrme interaction, our scheme does not utilize any a priori knowledge on the structure of nuclei. In our framework, we first generate a number of Slater determinants in a stochastic way. We then make projections of parity and angular momentum, and perform configuration mixing calculation. We show results for 12C and 16O nuclei. Our calculation provides a reasonable description for the ground state rotational band, Hoyle state, and low-lying negative parity states of 12C. We may also describe the 0+2 rotational band of 16O, although excitation energies are slightly overestimated.

  11. Deformation and cluster structures in 12C studied with configuration mixing using Skyrme interactions

    NASA Astrophysics Data System (ADS)

    Fukuoka, Y.; Shinohara, S.; Funaki, Y.; Nakatsukasa, T.; Yabana, K.

    2013-07-01

    We report an investigation of the structure of the 12C nucleus employing a newly developed configuration-mixing method. In the three-dimensional coordinate-space representation, we generate a number of Slater determinants with various correlated structures using the imaginary-time algorithm. We then diagonalize a many-body Hamiltonian with the Skyrme interaction in the space spanned by the Slater determinants with parity and angular momentum projections. Our calculation reasonably describes the ground and excited states of the 12C nucleus, both for shell-model-like and cluster-like states. The excitation energies and transition strengths of the ground-state rotational band are well reproduced. Negative-parity excited states, 11-, 21-, and 31-, are also reasonably described. The second and third 0+ states, 02+ and 03+, appear at around 8.8 and 15 MeV, respectively. The 02+ state shows a structure consistent with former results of the α-cluster models. However, the calculated radius of the 02+ state is smaller than in those calculations. The three-α linear-chain configuration dominates in the 03+ state.

  12. Isovector splitting of nucleon effective masses, ab initio benchmarks and extended stability criteria for Skyrme energy functionals

    SciTech Connect

    Lesinski, T.; Meyer, J.

    2006-10-15

    We study the effect of the splitting of neutron and proton effective masses with isospin asymmetry on the properties of the Skyrme energy density functional. We discuss the ability of the latter to predict observables of infinite matter and finite nuclei, paying particular attention to controlling the agreement with ab initio predictions of the spin-isospin content of the nuclear equation of state, as well as diagnosing the onset of finite size instabilities, which we find to be of critical importance. We show that these various constraints cannot be simultaneously fulfilled by the standard Skyrme force, calling at least for an extension of its P-wave part.

  13. Stochastic approach to correlations beyond the mean field with the Skyrme interaction

    NASA Astrophysics Data System (ADS)

    Fukuoka, Y.; Nakatsukasa, T.; Funaki, Y.; Yabana, K.

    2012-10-01

    Large-scale calculation based on the multi-configuration Skyrme density functional theory is performed for the light N = Z even-even nucleus, 12C. Stochastic procedures and the imaginary-time evolution are utilized to prepare many Slater determinants. Each state is projected on eigenstates of parity and angular momentum. Then, performing the configuration mixing calculation with the Skyrme Hamiltonian, we obtain low-lying energy-eigenstates and their explicit wave functions. The generated wave functions are completely free from any assumption and symmetry restriction. Excitation spectra and transition probabilities are well reproduced, not only for the ground-state band, but for negative-parity excited states and the Hoyle state.

  14. Extended Thomas-Fermi density functionals in the presence of a tensor interaction in spherical symmetry

    SciTech Connect

    Bartel, J.; Bencheikh, K.; Meyer, J.

    2008-02-15

    For a one-body Hamiltonian obtained from the energy-density functional associated with a Skyrme effective interaction, including a tensor force, semiclassical functional densities are derived in the framework of the Extended Thomas-Fermi method, in spherical symmetry, for the kinetic energy and spin-orbit density. The structure of the self-consistent mean-field potentials constructed with such semiclassical functionals is studied. The impact of the tensor force in particular on the spin-orbit form factor clearly indicates the necessity of including such tensor-force terms in the theoretical description of atomic nuclei and their possible influence on the shell structure of exotic nuclei.

  15. On the theory of phase transitions in dense neutron matter with generalized Skyrme interactions and anisotropic spin-triplet p-wave pairing in strong magnetic field

    NASA Astrophysics Data System (ADS)

    Tarasov, A. N.

    2014-03-01

    In the framework of the generalized non-relativistic Fermi-liquid approach we study phase transitions in spatially uniform dense pure neutron matter from normal to superfluid states with a spin-triplet p-wave pairing (similar to anisotropic superfluid phases 3He-A1 and 3He-A2) in a steady and homogeneous strong magnetic field H (but |\\mu_{\\text{n}}| H\\ll E_{\\text{c}}<\\varepsilon_{\\text{F}}(n) , where \\mu_{\\text{n}} is the magnetic dipole moment of a neutron, E_{\\text{c}} is the cutoff energy and \\varepsilon_{\\text{F}}(n) is the Fermi energy in neutron matter with density of particles n). The previously derived general formulas (valid for the arbitrary parametrization of the effective Skyrme interaction in neutron matter) for phase transition (PT) temperatures T_{\\text{c}1,2}(n,H) (which are nonlinear functions of the density n and linear functions of the magnetic field H) are specified here for new generalized BSk20 and BSk21 parameterizations of the Skyrme forces (with additional terms dependent on the density n) in the interval 0.1\\cdot n_{0} < n<3.0\\cdot n_{0} , where n_{0}=0.17\\ \\text{fm}^{-3} is the nuclear density. Our main results are mathematical expressions and figures for PT temperatures in the absence of magnetic field, T_{\\text{c0,BSk20}}(n)< 0.17\\ \\text{MeV} and T_{\\text{c0,BSk21}}(n)< 0.064\\ \\text{MeV} (at E_{\\text{c}}=10\\ \\text{MeV} ), and T_{\\text{c1,2}}(n,H) in strong magnetic fields (which may approach to 10^{17}\\ \\text{G} or even more as in the liquid outer core of magnetars —strongly magnetized neutron stars). These are realistic non-monotone functions with a bell-shaped density profile.

  16. Exact results in the Skyrme model in (3+1) dimensions via the generalized hedgehog ansatz

    NASA Astrophysics Data System (ADS)

    Canfora, Fabrizio

    2016-09-01

    We present exact results in the (3 + 1) -dimensional Skyrme model. First of all, it will be shown that, in the Pionic sector, a quite remarkable phenomenon for a non-integrable (3 + 1) -dimensional field theory appears: a non-linear superposition law is available allowing the composition of solutions in order to generate new solutions of the full field equations keeping alive, at the same time, the interactions terms in the energy-density. Secondly, it will be shown that the generalized hedgehog ansatz can be extended to suitable curved backgrounds. Interestingly, one can choose the background metric in such a way to describe finite-volume effects and, at the same time, to simplify the Skyrme field equations. In this way, it is possible to construct the first exact multi-Skyrmionic configurations of the (3 + 1) -dimensional Skyrme model with arbitrary high winding number and living at finite volume. Last but not least, a novel BPS bound (which is sharper than the usual one in term of the winding number) will be derived which can be saturated and reduces the field equations to a first-order equation for the profile.

  17. Gauged multisoliton baby Skyrme model

    NASA Astrophysics Data System (ADS)

    Samoilenka, A.; Shnir, Ya.

    2016-03-01

    We present a study of U (1 ) gauged modification of the 2 +1 -dimensional planar Skyrme model with a particular choice of the symmetry breaking potential term which combines a short-range repulsion and a long-range attraction. In the absence of the gauge interaction, the multisolitons of the model are aloof, as they consist of the individual constituents which are well separated. A peculiar feature of the model is that there are usually several different stable static multisoliton solutions of rather similar energy in a topological sector of given degree. We investigate the pattern of the solutions and find new previously unknown local minima. It is shown that coupling of the aloof planar multi-Skyrmions to the magnetic field strongly affects the pattern of interaction between the constituents. We analyze the dependency of the structure of the solutions, their energies, and magnetic fluxes on the strength of the gauge coupling. It is found that, generically, in the strong coupling limit, the coupling to the gauge field results in effective recovery of the rotational invariance of the configuration.

  18. Baby Skyrme model, near-BPS approximations, and supersymmetric extensions

    NASA Astrophysics Data System (ADS)

    Bolognesi, S.; Zakrzewski, W.

    2015-02-01

    We study the baby Skyrme model as a theory that interpolates between two distinct BPS systems. For this, a near-BPS approximation can be used when there is a small deviation from each of the two BPS limits. We provide analytical explanation and numerical support for the validity of this approximation. We then study the set of all possible supersymmetric extensions of the baby Skyrme model with N =1 and the particular ones with extended N =2 supersymmetries and relate this to the above mentioned almost-BPS approximation.

  19. Effect of the tensor part of Skyrme interaction on the description of elastic nucleon-nucleus scattering on the basis of the optical model

    SciTech Connect

    Kuprikov, V. I.; Pilipenko, V. V.

    2013-01-15

    A microscopic optical nucleon-nucleus potential constructed on the basis of calculating the mass operator for the single-particle Green's function with Skyrme nucleon-nucleon forces was used to study the effect of the tensor part of Skyrme forces on describing differential cross sections for elastic nucleon-nucleus scattering and the structure of nuclei within a self-consistent approach. It was shown that an increase in the tensor terms of nucleon-nucleon forces impaired the description of nucleon-nucleus scattering within the model being considered. The parameters of Skyrme forces were optimized on the basis of an analysis of cross sections for neutron-nucleus scattering, the properties of nuclear matter and the structure of nuclei being tested in doing this. This optimization led to nucleon-nucleon force versions where the tensor part was small or zero and which described satisfactorily the structure of nuclei and cross sections for elastic neutron and proton scattering on nuclei over a broad range of target mass numbers.

  20. Nuclear matter magnetization in the Skyrme model

    SciTech Connect

    Aguirre, R.

    2011-05-15

    The effects of an external magnetic field on the nuclear medium are studied within the Skyrme model of the nuclear interaction. The equation of state, spin polarization, and magnetization are evaluated at zero temperature for both neutron matter and isospin symmetric nuclear matter. We consider the anomalous magnetic moments of the nucleons and the quantization induced by a magnetic field over the proton energy spectrum. A comparison of two versions of the model, allowing or not for spontaneous magnetization, is performed. We cover a range of magnetic-field strengths and matter densities appropriate for astrophysical studies.

  1. Inflating baby-Skyrme branes in six dimensions

    SciTech Connect

    Brihaye, Yves; Delsate, Terence; Kodama, Yuta; Sawado, Nobuyuki

    2010-11-15

    We consider a six-dimensional brane world model, where the brane is described by a localized solution to the baby-Skyrme model extending in the extra dimensions. The branes have a cosmological constant modeled by inflating four-dimensional slices, and we further consider a bulk cosmological constant. We construct solutions numerically and present evidence that the solutions cease to exist for large values of the brane cosmological constant in some particular case. Then we study the stability of the model by considering perturbation of the gravitational part (resp. baby Skyrmion) with fixed matter fields (resp. gravitational background). Our results indicate that the perturbation equations do not admit localized solutions for certain type of perturbation. The stability analysis can be alternatively seen as leading to a particle spectrum; we give mass estimations for the baby-Skyrme perturbation and for the graviton.

  2. Extending theories on muon-specific interactions

    SciTech Connect

    Carlson, Carl E.; Freid, Michael C.

    2015-11-23

    The proton radius puzzle, the discrepancy between the proton radius measured in muonic hydrogen and electronic hydrogen, has yet to be resolved. There are suggestions that beyond the standard model (BSM) physics could resolve both this puzzle and the muon anomalous magnetic moment discrepancy. Karshenboim et al. point out that simple, nonrenormalizable, models in this direction involving new vector bosons have serious problems when confronting high energy data. The prime example is radiative corrections to W to μν decay which exceed experimental bounds. We show how embedding the model in a larger and arguably renormalizable theory restores gauge invariance of the vector particle interactions and controls the high energy behavior of decay and scattering amplitudes. Thus BSM explanations of the proton radius puzzle can still be viable.

  3. Extending theories on muon-specific interactions

    DOE PAGESBeta

    Carlson, Carl E.; Freid, Michael C.

    2015-11-23

    The proton radius puzzle, the discrepancy between the proton radius measured in muonic hydrogen and electronic hydrogen, has yet to be resolved. There are suggestions that beyond the standard model (BSM) physics could resolve both this puzzle and the muon anomalous magnetic moment discrepancy. Karshenboim et al. point out that simple, nonrenormalizable, models in this direction involving new vector bosons have serious problems when confronting high energy data. The prime example is radiative corrections to W to μν decay which exceed experimental bounds. We show how embedding the model in a larger and arguably renormalizable theory restores gauge invariance ofmore » the vector particle interactions and controls the high energy behavior of decay and scattering amplitudes. Thus BSM explanations of the proton radius puzzle can still be viable.« less

  4. Investigation of restricted baby Skyrme models

    SciTech Connect

    Adam, C.; Romanczukiewicz, T.; Wereszczynski, A.; Sanchez-Guillen, J.

    2010-04-15

    A restriction of the baby Skyrme model consisting of the quartic and potential terms only is investigated in detail for a wide range of potentials. Further, its properties are compared with those of the corresponding full baby Skyrme models. We find that topological (charge) as well as geometrical (nucleus/shell shape) features of baby Skyrmions are captured already by the soliton solutions of the restricted model. Further, we find a coincidence between the compact or noncompact nature of solitons in the restricted model, on the one hand, and the existence or nonexistence of multi-Skyrmions in the full baby Skyrme model, on the other hand.

  5. Baby Skyrme models without a potential term

    NASA Astrophysics Data System (ADS)

    Ashcroft, Jennifer; Haberichter, Mareike; Krusch, Steffen

    2015-05-01

    We develop a one-parameter family of static baby Skyrme models that do not require a potential term to admit topological solitons. This is a novel property as the standard baby Skyrme model must contain a potential term in order to have stable soliton solutions, though the Skyrme model does not require this. Our new models satisfy an energy bound that is linear in terms of the topological charge and can be saturated in an extreme limit. They also satisfy a virial theorem that is shared by the Skyrme model. We calculate the solitons of our new models numerically and observe that their form depends significantly on the choice of parameter. In one extreme, we find compactons while at the other there is a scale invariant model in which solitons can be obtained exactly as solutions to a Bogomolny equation. We provide an initial investigation into these solitons and compare them with the baby Skyrmions of other models.

  6. Monopoles and knots in skyrme theory.

    PubMed

    Cho, Y M

    2001-12-17

    We show that the Skyrme theory is actually a theory of monopoles which allows a new type of soliton, the topological knot made of the monopole-antimonopole pair, which is different from the well-known skyrmion. Furthermore, we derive a generalized Skyrme action from the Yang-Mills action of QCD, which we propose to be an effective action of QCD in the infrared limit. We discuss the physical implications of our results. PMID:11736568

  7. Baryon spectrum of the Skyrme model

    NASA Astrophysics Data System (ADS)

    Mattis, Michael P.; Karliner, Marek

    1985-06-01

    We calculate the spectrum of nucleon and Δ resonances of the Skyrme model. The masses that we find are accurate on the average to within 8% of their experimental values up to 3 GeV. For most partial waves the model reproduces many significant features of the experimental Argand diagrams correctly. The values of the Skyrme parameters obtained from a best fit to the spectrum improve some of the static properties of the model.

  8. Extended cognition and the space of social interaction.

    PubMed

    Krueger, Joel

    2011-09-01

    The extended mind thesis (EM) asserts that some cognitive processes are (partially) composed of actions consisting of the manipulation and exploitation of environmental structures. Might some processes at the root of social cognition have a similarly extended structure? In this paper, I argue that social cognition is fundamentally an interactive form of space management--the negotiation and management of "we-space"--and that some of the expressive actions involved in the negotiation and management of we-space (gesture, touch, facial and whole-body expressions) drive basic processes of interpersonal understanding and thus do genuine social-cognitive work. Social interaction is a kind of extended social cognition, driven and at least partially constituted by environmental (non-neural) scaffolding. Challenging the Theory of Mind paradigm, I draw upon research from gesture studies, developmental psychology, and work on Moebius Syndrome to support this thesis. PMID:20970358

  9. Fission barriers for neutron-rich nuclei by means of Skyrme-Hartree-Fock-Bogoliubov calculation

    SciTech Connect

    Hashizume, K.; Wada, T.; Ohta, M.; Samyn, M.; Goriely, S.

    2007-02-26

    The nuclear fission barrier height has been estimated by means of the constraint Skyrme Hartree-Fock-Bogoliubov method. The potential energy surfaces obtained by the method are analyzed with the flooding method to find several saddle points. The results for U, Np, Bk isotopes are compared with the barrier derived from the extended Thomas-Fermi plus Strutinsky integral method.

  10. Hyperon puzzle of neutron stars with Skyrme force models

    NASA Astrophysics Data System (ADS)

    Lim, Yeunhwan; Hyun, Chang Ho; Kwak, Kyujin; Lee, Chang-Hwan

    2015-12-01

    We consider the so-called hyperon puzzle of neutron star (NS). We employ Skyrme force models for the description of in-medium nucleon-nucleon (NN), nucleon-Lambda hyperon (NΛ) and Lambda-Lambda (ΛΛ) interactions. A phenomenological finite-range force (FRF) for the ΛΛ interaction is considered as well. Equation of state (EoS) of NS matter is obtained in the framework of density functional theory, and Tolman-Oppenheimer-Volkoff (TOV) equations are solved to obtain the mass-radius relations of NSs. It has been generally known that the existence of hyperons in the NS matter is not well supported by the recent discovery of large-mass NSs (M ≃ 2M⊙) since hyperons make the EoS softer than the one without them. For the selected interaction models, NΛ interactions reduce the maximum mass of NS by about 30%, while ΛΛ interactions can give about 10% enhancement. Consequently, we find that some Skyrme force models predict the maximum mass of NS consistent with the observation of 2M⊙ NSs, and at the same time satisfy observationally constrained mass-radius relations.

  11. Dynamics of magnetic bubbles in a Skyrme model

    NASA Astrophysics Data System (ADS)

    Papanicolaou, N.; Zakrzewski, W. J.

    1996-01-01

    The dynamics of magnetic bubbles is studied within a strictly 2D model in which a Skyrme-like term is included to ensure stability. We calculate the profile of static bubbles with unit winding number and then examine two basic dynamical questions. First, we demonstrate that magnetic bubbles exhibit skew deflection in an applied magnetic-field gradient where the semi-empirical golden rule of bubble dynamics is verified in its gross features but not its finer details. Second, we show that two interacting magnetic bubbles with the same winding number orbit around each other while undergoing a mild Larmor precession.

  12. Compact and extended objects from self-interacting phantom fields

    NASA Astrophysics Data System (ADS)

    Dzhunushaliev, Vladimir; Folomeev, Vladimir; Makhmudov, Arislan; Urazalina, Ainur; Singleton, Douglas; Scott, John

    2016-07-01

    In this work, we investigate localized and extended objects for gravitating, self-interacting phantom fields. The phantom fields come from two scalar fields with a "wrong-sign" (negative) kinetic energy term in the Lagrangian. This study covers several solutions supported by these phantom fields: phantom balls, traversable wormholes, phantom cosmic strings, and "phantom" domain walls. These four systems are solved numerically, and we try to draw out general, interesting features in each case.

  13. RKKY interaction between extended magnetic defect lines in graphene

    NASA Astrophysics Data System (ADS)

    Gorman, P. D.; Duffy, J. M.; Power, S. R.; Ferreira, M. S.

    2014-09-01

    Of fundamental interest in the field of spintronics is the mechanism of indirect exchange coupling between magnetic impurities embedded in metallic hosts. A range of physical features, such as magnetotransport and overall magnetic moment formation, are predicated upon this magnetic coupling, often referred to as the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction. Recent theoretical studies on the RKKY in graphene have been motivated by possible spintronic applications of magnetically doped graphene systems. In this paper a combination of analytic and numerical techniques are used to examine the effects of defect dimensionality on such an interaction. We show, in a mathematically transparent manner, that moving from single magnetic impurities to extended lines of impurities effectively reduces the dimensionality of the system and increases the range of the interaction. This has important consequences for the spintronic application of magnetically-doped systems, and we illustrate this with a simple magnetoresistance device.

  14. Skyrme-Einstein closed cosmic chiral strings

    SciTech Connect

    Rybakov, Yu. P. Ivanova, I. S.

    2007-07-15

    Within the theory of general relativity, the configuration of a closed string (vortex) characterized by a topological charge of the degree type is described for the Skyrme-Einstein SU (2) chiral model. In the approximation of a large vortex-closure radius (a), a solution to equations of motion is obtained, along with estimates for the vortex energy and radius.

  15. Tensor part of the Skyrme energy density functional: Spherical nuclei

    NASA Astrophysics Data System (ADS)

    Lesinski, T.; Bender, M.; Bennaceur, K.; Duguet, T.; Meyer, J.

    2007-07-01

    We perform a systematic study of the impact of the J2 tensor term in the Skyrme energy functional on properties of spherical nuclei. In the Skyrme energy functional, the tensor terms originate from both zero-range central and tensor forces. We build a set of 36 parametrizations, covering a wide range of the parameter space of the isoscalar and isovector tensor term coupling constants with a fit protocol very similar to that of the successful SLy parametrizations. We analyze the impact of the tensor terms on a large variety of observables in spherical mean-field calculations, such as the spin-orbit splittings and single-particle spectra of doubly-magic nuclei, the evolution of spin-orbit splittings along chains of semi-magic nuclei, mass residuals of spherical nuclei, and known anomalies of radii. The major findings of our study are as follows: (i) Tensor terms should not be added perturbatively to existing parametrizations; a complete refit of the entire parameter set is imperative. (ii) The free variation of the tensor terms does not lower the χ2 within a standard Skyrme energy functional. (iii) For certain regions of the parameter space of their coupling constants, the tensor terms lead to instabilities of the spherical shell structure, or even to the coexistence of two configurations with different spherical shell structures. (iv) The standard spin-orbit interaction does not scale properly with the principal quantum number, such that single-particle states with one or several nodes have too large spin-orbit splittings, whereas those of nodeless intruder levels are tentatively too small. Tensor terms with realistic coupling constants cannot cure this problem. (v) Positive values of the coupling constants of proton-neutron and like-particle tensor terms allow for a qualitative description of the evolution of spin-orbit splittings in chains of Ca, Ni, and Sn isotopes. (vi) For the same values of the tensor term coupling constants, however, the overall agreement of

  16. Vacuum alignment in the breaking of extended hypercolor interactions

    NASA Astrophysics Data System (ADS)

    León, J.; Ramón-Medrano, M.

    1983-08-01

    We analyze how the search for the true vacuum at the first breaking of an extended-hypercolor-interaction theory determines the physics at energies of the order of ΛHC. The effects of vacuum alignment on the light-fermion spectrum-number of families, isospin violations in fermion mass matrices, along with pseudo-Goldstone-boson and gauge-meson spectra-are explicitly shown in a SUL(2)×SUC(3)×UY(1)×SUEHC(8)×OHC'(6) model.

  17. Solitons in Skyrme - Faddeev spinor model and quantum mechanics

    NASA Astrophysics Data System (ADS)

    Rybakov, Y.

    2016-07-01

    We discuss the possibility of unification of Skyrme and Faddeev approaches for the description of baryons and leptons respectively as topological solitons within the scope of 16-spinor model. The motivation for such a unification is based on a special 8- semispinor identity invented by the Italian geometrician F. Brioschi. This remarkable identity permits one to realize baryon or lepton states through the effect of spontaneous symmetry breaking emerging due to special structure of the Higgs potential in the model. At large distances from the particle - soliton small excitation of the vacuum satisfies Klein - Gordon equation with some mass that permits one to establish the correspondence with quantum mechanics in special stochastic representation of the wave function for extended particles - solitons. Finally, we illustrate the peculiar properties of stochastic representation by the famous T. Young's experiment with n slits in soliton realization.

  18. Exact kink solitons in Skyrme crystals

    NASA Astrophysics Data System (ADS)

    Chen, Shouxin; Li, Yijun; Yang, Yisong

    2014-01-01

    We present an explicit integration of the kink soliton equation obtained in a recent interesting study of the classical Skyrme model where the field configurations are of a generalized hedgehog form which is of a domain-wall type. We also show that in such a reduced one-dimensional setting the first-order and second-order equations are equivalent. Consequently, in such a context, all finite-energy solitons are Bogomolnyi-Prasad-Sommerfield type and precisely known.

  19. The extended interacting wind structure of Eta Carinae

    NASA Astrophysics Data System (ADS)

    Gull, T. R.; Nielsen, K. E.; Corcoran, M. F.; Madura, T. I.; Owocki, S. P.; Russell, C. M. P.; Hillier, D. J.; Hamaguchi, K.; Kober, G. V.; Weis, K.; Stahl, O.; Okazaki, A. T.

    2009-07-01

    The highly eccentric binary system, η Car, provides clues to the transition of massive stars from hydrogen-burning via the CNO cycle to a helium-burning evolutionary state. The fast-moving wind of η Car B creates a cavity in η Car A's slower, but more massive, stellar wind, providing an in situ probe. The Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS), with its high spatial and spectral resolutions, is well matched to follow temporal spatial and velocity variations of multiple wind features. We use observations obtained across 1998-2004 to produce a rudimentary three-dimensional model of the wind interaction in the η Car system. Broad (+/-500 km s-1) [FeII] emission line structures extend 0.7arcsec (~1600 au) from the stellar core. In contrast, [FeIII], [ArIII], [NeIII] and [SIII] lines extend only 0.3arcsec (700 au) from NE to SW and are blue shifted from -500 to +200 km s-1. All observed spectral features vary with the 5.54-year orbital period. The highly ionized, forbidden emission disappears during the low state, associated with periastron passage. The high-ionization emission originates in the outer wind interaction region that is directly excited by the far-ultraviolet radiation from η Car B. The HST/STIS spectra reveal a time-varying, distorted paraboloidal structure, caused by the interaction of the massive stellar winds. The model and observations are consistent with the orbital plane aligned with the skirt of the Homunculus. However, the axis of the distorted paraboloid, relative to the major axis of the binary orbit, is shifted in a prograde rotation along the plane, which projected on the sky is from NE to NW. Based on observations made with the National Aeronautics and Space Agency/European Space Agency (NASA/ESA) HST. Support for Programme numbers 7302, 8036, 8483, 8619, 9083, 9337, 9420, 9973, 10957 and 11273 was provided by NASA directly to the Space Telescope Imaging Spectrograph Science Team and through grants from the

  20. Baryon-Baryon Interactions ---Nijmegen Extended-Soft-Core Models---

    NASA Astrophysics Data System (ADS)

    Rijken, T. A.; Nagels, M. M.; Yamamoto, Y.

    We review the Nijmegen extended-soft-core (ESC) models for the baryon-baryon (BB) interactions of the SU(3) flavor-octet of baryons (N, Lambda, Sigma, and Xi). The interactions are basically studied from the meson-exchange point of view, in the spirit of the Yukawa-approach to the nuclear force problem [H. Yukawa, ``On the interaction of Elementary Particles I'', Proceedings of the Physico-Mathematical Society of Japan 17 (1935), 48], using generalized soft-core Yukawa-functions. These interactions are supplemented with (i) multiple-gluon-exchange, and (ii) structural effects due to the quark-core of the baryons. We present in some detail the most recent extended-soft-core model, henceforth referred to as ESC08, which is the most complete, sophisticated, and successful interaction-model. Furthermore, we discuss briefly its predecessor the ESC04-model [Th. A. Rijken and Y. Yamamoto, Phys. Rev. C 73 (2006), 044007; Th. A. Rijken and Y. Yamamoto, Ph ys. Rev. C 73 (2006), 044008; Th. A. Rijken and Y. Yamamoto, nucl-th/0608074]. For the soft-core one-boson-exchange (OBE) models we refer to the literature [Th. A. Rijken, in Proceedings of the International Conference on Few-Body Problems in Nuclear and Particle Physics, Quebec, 1974, ed. R. J. Slobodrian, B. Cuec and R. Ramavataram (Presses Universitè Laval, Quebec, 1975), p. 136; Th. A. Rijken, Ph. D. thesis, University of Nijmegen, 1975; M. M. Nagels, Th. A. Rijken and J. J. de Swart, Phys. Rev. D 17 (1978), 768; P. M. M. Maessen, Th. A. Rijken and J. J. de Swart, Phys. Rev. C 40 (1989), 2226; Th. A. Rijken, V. G. J. Stoks and Y. Yamamoto, Phys. Rev. C 59 (1999), 21; V. G. J. Stoks and Th. A. Rijken, Phys. Rev. C 59 (1999), 3009]. All ingredients of these latter models are also part of ESC08, and so a description of ESC08 comprises all models so far in principle. The extended-soft-core (ESC) interactions consist of local- and non-local-potentials due to (i) one-boson-exchanges (OBE), which are the members of nonets of

  1. Nuclear Mass Predictions within the Skyrme HFB Theory

    SciTech Connect

    Samyn, M.; Goriely, S.; Pearson, J.M.

    2005-05-24

    To increase the reliability of predictions of highly neutron-rich nuclear masses we systematically analyze the sensitivity of Hartree-Fock-Bogoliubov (HFB) mass formulae to various physical inputs, such as a density dependence of the pairing interaction, a low effective mass, the particle-number projection, the symmetry energy, ... We typically use a 10-parameter Skyrme force and a 4-parameter {delta}-function pairing force. The 14 degrees of freedom are adjusted to the masses of all measured nuclei with N,Z {>=} 8 given in the 2001 and 2003 Audi et al. compilations. The masses of light and proton-rich nuclei are corrected by a 4-parameter phenomenological Wigner term. With more than ten such parameter sets complete mass tables are constructed, going from one drip line to the other, up to Z = 120.

  2. Nuclear Mass Predictions within the Skyrme HFB Theory

    NASA Astrophysics Data System (ADS)

    Samyn, M.; Goriely, S.; Pearson, J. M.

    2005-05-01

    To increase the reliability of predictions of highly neutron-rich nuclear masses we systematically analyze the sensitivity of Hartree-Fock-Bogoliubov (HFB) mass formulae to various physical inputs, such as a density dependence of the pairing interaction, a low effective mass, the particle-number projection, the symmetry energy, … We typically use a 10-parameter Skyrme force and a 4-parameter δ-function pairing force. The 14 degrees of freedom are adjusted to the masses of all measured nuclei with N,Z ⩾ 8 given in the 2001 and 2003 Audi et al. compilations. The masses of light and proton-rich nuclei are corrected by a 4-parameter phenomenological Wigner term. With more than ten such parameter sets complete mass tables are constructed, going from one drip line to the other, up to Z = 120.

  3. Skyrme-like models and supersymmetry in 3 +1 dimensions

    NASA Astrophysics Data System (ADS)

    Queiruga, J. M.

    2015-11-01

    We construct supersymmetric extensions for different Skyrme-like models in 3 +1 dimensions. BPS equations and BPS bounds are obtained from supersymmetry in some cases. We discuss also the emergence of several Skyrme-like models from supersymmetric Yang-Mills theory and Born-Infeld theory in 5 dimensions.

  4. ``Half a proton'' in the Bogomol'nyi-Prasad-Sommerfield Skyrme model

    NASA Astrophysics Data System (ADS)

    Lukács, Árpád

    2016-07-01

    The BPS Skyrme model is a model containing an SU(2)-valued scalar field, in which a Bogomol'nyi-type inequality can be satisfied by soliton solutions (skyrmions). In this model, the energy density of static configurations is the sum of the square of the topological charge density plus a potential. The topological charge density is nothing else but the pull-back of the Haar measure of the group SU(2) on the physical space by the field configuration. As a consequence, this energy expression has a high degree of symmetry: it is invariant to volume preserving diffeomorphisms both on physical space and on the target space. We demonstrate here that in the BPS Skyrme model such solutions exist that a fraction of its charge and energy densities is localised, and the remaining part can be far away, not interacting with the localised part.

  5. Extending Interactive Writing into Grades 2-5

    ERIC Educational Resources Information Center

    Roth, Kate; Dabrowski, Joan

    2014-01-01

    Interactive writing is an instructional practice widely considered effective and most appropriate for emergent writers. This article asserts that it is a valuable method for more fluent writers in grades 2-5. It outlines the basic lesson sequence and proposes four key shifts to adapt interactive writing for older, more fluent writers: 1) The…

  6. Relativistic interactions and realistic applications

    SciTech Connect

    Hoch, T.; Madland, D.; Manakos, P.; Mannel, T.; Nikolaus, B.A.; Strottman, D. |

    1992-12-31

    A four-fermion-coupling Lagrangian (relativistic Skyrme-type) interaction has been proposed for relativistic nuclear structure calculations. This interaction, which has the merit of simplicity, is from the outset tailored as an effective interaction for relativistic Hartree-Fock calculations. Various extensions of such a model are discussed and compared with Walecka`s meson-nucleon mean field approach. We also present results of the calculation of nuclear ground state properties with an extended (density dependent) version of the four fermion interaction in a relativistic Hartree-Fock approximation.

  7. Skyrme tensor force in heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Stevenson, P. D.; Suckling, E. B.; Fracasso, S.; Barton, M. C.; Umar, A. S.

    2016-05-01

    Background: It is generally acknowledged that the time-dependent Hartree-Fock (TDHF) method provides a useful foundation for a fully microscopic many-body theory of low-energy heavy ion reactions. The TDHF method is also known in nuclear physics in the small-amplitude domain, where it provides a useful description of collective states, and is based on the mean-field formalism, which has been a relatively successful approximation to the nuclear many-body problem. Currently, the TDHF theory is being widely used in the study of fusion excitation functions, fission, and deep-inelastic scattering of heavy mass systems, while providing a natural foundation for many other studies. Purpose: With the advancement of computational power it is now possible to undertake TDHF calculations without any symmetry assumptions and incorporate the major strides made by the nuclear structure community in improving the energy density functionals used in these calculations. In particular, time-odd and tensor terms in these functionals are naturally present during the dynamical evolution, while being absent or minimally important for most static calculations. The parameters of these terms are determined by the requirement of Galilean invariance or local gauge invariance but their significance for the reaction dynamics have not been fully studied. This work addresses this question with emphasis on the tensor force. Method: The full version of the Skyrme force, including terms arising only from the Skyrme tensor force, is applied to the study of collisions within a completely symmetry-unrestricted TDHF implementation. Results: We examine the effect on upper fusion thresholds with and without the tensor force terms and find an effect on the fusion threshold energy of the order several MeV. Details of the distribution of the energy within terms in the energy density functional are also discussed. Conclusions: Terms in the energy density functional linked to the tensor force can play a non

  8. Interacting extended Chaplygin gas cosmology in Lyra manifold

    NASA Astrophysics Data System (ADS)

    Khurshudyan, Martiros

    2015-12-01

    Subject of our interest is an extended Chaplygin gas cosmology and new receipts providing accelerated expansion of the large scale universe. In Literature a variety of cosmological models exist studying the behavior of the universe in the presence of Chaplygin gas. From its initial form Chaplygin gas evolved and accepted different EoS-s and we will work with one of them. The main purpose of this work is to study behavior of the universe in Lyra Manifold with a varying \\varLambda-term, which does give us modified field equations. Modified field equations compared to field equations of General Relativity provide a new parametrization of dark energy sector of the large scale universe. It is also interesting to study the behavior of the universe in case of an existing coupling between quintessence DE and extended Chaplygin gas. We applied observational constraints and causality issue to separate physically relevant behavior of the phenomenological model.

  9. Skyrme black holes in the isolated horizons formalism

    SciTech Connect

    Nielsen, Alex B.

    2006-08-15

    We study static, spherically symmetric, Skyrme black holes in the context of the assumption that they can be viewed as bound states between ordinary bare black holes and solitons. This assumption and results stemming from the isolated horizons formalism lead to several conjectures about the static black hole solutions. These conjectures are tested against the Skyrme black hole solutions. It is shown that, while there is in general good agreement with the conjectures, a crucial aspect seems to violate one of the conjectures.

  10. Kantowski-Sachs universes sourced by a Skyrme fluid

    NASA Astrophysics Data System (ADS)

    Parisi, Luca; Radicella, Ninfa; Vilasi, Gaetano

    2015-03-01

    The Kantowski-Sachs cosmological model sourced by a Skyrme field and a cosmological constant is considered in the framework of general relativity. Assuming a constant radial profile function α =π /2 for the hedgehog ansatz, the Skyrme contribution to Einstein equations is shown to be equivalent to an anisotropic fluid. Using dynamical system techniques, a qualitative analysis of the cosmological equations is presented. Physically interesting features of the model such as isotropization, bounce and recollapse are discussed.

  11. Comparing Extended System Interactions with Motions in Softened Potentials

    NASA Astrophysics Data System (ADS)

    Barnes, Eric I.

    2016-08-01

    Using an N-body evolution code that does not rely on softened potentials, I have created a suite of unbound interacting cluster pair simulations. The motions of the centers of mass of the clusters have been tracked and compared to the trajectories of point masses interacting via one of four different softened potential prescriptions. I find that the relationship between the impact parameter of the cluster interaction and the point-mass softening length that best approximates each cluster’s center-of-mass motion depends on the adopted prescription. In general, the range of allowed softening lengths grows roughly linearly with the impact parameter, but zero softening is acceptable in the majority of situations. In an N-body simulation that adopts a fixed softening length, such relationships lead to the possibility of two-body effects, like dynamical friction, being either larger or smaller than the corresponding cluster situation. Further consideration of more specific N-body situations leads to estimating that a very small fraction of point-mass encounters experience two-body effects significantly different from those of equivalent clusters.

  12. Description of induced nuclear fission with Skyrme energy functionals. II. Finite temperature effects

    NASA Astrophysics Data System (ADS)

    Schunck, N.; Duke, D.; Carr, H.

    2015-03-01

    Understanding the mechanisms of induced nuclear fission for a broad range of neutron energies could help resolve fundamental science issues, such as the formation of elements in the universe, but could have also a large impact on societal applications in energy production or nuclear waste management. The goal of this paper is to set up the foundations of a microscopic theory to study the static aspects of induced fission as a function of the excitation energy of the incident neutron, from thermal to fast neutrons. To account for the high excitation energy of the compound nucleus, we employ a statistical approach based on finite temperature nuclear density functional theory with Skyrme energy densities, which we benchmark on the 239Pu(n ,f ) reaction. We compute the evolution of the least-energy fission pathway across multidimensional potential energy surfaces with up to five collective variables as a function of the nuclear temperature and predict the evolution of both the inner and the outer fission barriers as a function of the excitation energy of the compound nucleus. We show that the coupling to the continuum induced by the finite temperature is negligible in the range of neutron energies relevant for many applications of neutron-induced fission. We prove that the concept of quantum localization introduced recently can be extended to T >0 , and we apply the method to study the interaction energy and total kinetic energy of fission fragments as a function of the temperature for the most probable fission. While large uncertainties in theoretical modeling remain, we conclude that a finite temperature nuclear density functional may provide a useful framework to obtain accurate predictions of fission fragment properties.

  13. Peakons and Q-balls in the baby Skyrme model

    SciTech Connect

    Lis, Jakub

    2011-10-15

    In this paper, we investigate the Q-ball Ansatz in the baby Skyrme model. First, the appearance of peakons, i.e. solutions with extremely large absolute values of the second derivative at maxima, is analyzed. It is argued that such solutions are intrinsic to the baby Skyrme model and do not depend on the detailed form of a potential used in calculations. Next, we concentrate on compact nonspinning Q-balls. We show the failure of a small parameter expansion in this case. Finally, we explore the existence and parameter dependence of Q-ball solutions.

  14. Skyrme models and nuclear matter equation of state

    NASA Astrophysics Data System (ADS)

    Adam, C.; Haberichter, M.; Wereszczynski, A.

    2015-11-01

    We investigate the role of pressure in a class of generalized Skyrme models. We introduce pressure as the trace of the spatial part of the energy-momentum tensor and show that it obeys the usual thermodynamical relation. Then, we compute analytically the mean-field equation of state in the high- and medium-pressure regimes by applying topological bounds on compact domains. The equation of state is further investigated numerically for the charge-one Skyrmions. We identify which term in a generalized Skyrme model is responsible for which part in the equation of state. Further, we compare our findings with the corresponding results in the Walecka model.

  15. Analysis of Verbal Interactions during an Extended, Open-Inquiry General Chemistry Laboratory Investigation

    ERIC Educational Resources Information Center

    Krystyniak, Rebecca A.; Heikkinen, Henry W.

    2007-01-01

    This study explores effects of participation by second-semester college general chemistry students in an extended, open-inquiry laboratory investigation. Verbal interactions among a student lab team and with their instructor over three open-inquiry laboratory sessions and two non-inquiry sessions were recorded, transcribed, and analyzed. Coding…

  16. Role of surface gauging in extended particle interactions: The case for spin

    NASA Astrophysics Data System (ADS)

    Mazilu, Nicolae; Ghizdovat, Vlad; Agop, Maricel

    2016-05-01

    The matter, being extended in space, should be first characterized by a surface of separation from the empty space. This surface cannot be neatly, i.e. purely geometrically, defined. When it comes to extended particles, which thereby are to be considered the fundamental structural units of the matter, the physical evidence points out that they are not even stable: they are in a continuous transformation; and so is their limit of separation from space. The present work describes a concept of extended particle with special emphasis on this limit of separation. It turns out that the properties of inertia, as classically understood, are intrinsically related to the spin properties of quantum origin. Thus, an extended particle model cannot be but "holographic" when it comes to imbedding it in a physical structure. The spin properties turn out to be essential, inasmuch as they decide the forces of interaction issuing from particles.

  17. Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. XVI. Inclusion of self-energy effects in pairing

    NASA Astrophysics Data System (ADS)

    Goriely, S.; Chamel, N.; Pearson, J. M.

    2016-03-01

    Extending our earlier work, a new family of three Hartree-Fock-Bogoliubov (HFB) mass models, labeled HFB-30, HFB-31, and HFB-32, is presented, along with their underlying interactions, BSk30, BSk31, and BSk32, respectively. The principle new feature is a purely phenomenological pairing term that depends on the density gradient. This enables us to have a bulk pairing term that is fitted to realistic nuclear-matter calculations in which for the first time the self-energy corrections are included, while the behavior of the nucleon effective masses in asymmetric homogeneous nuclear matter is significantly improved. Furthermore, in the particle-hole channel all the highly realistic constraints of our earlier work are retained. In particular, the unconventional Skyrme forces containing t4 and t5 terms are still constrained to fit realistic equations of state of neutron matter stiff enough to support the massive neutron stars PSR J1614-2230 and PSR J0348+0432. All unphysical long-wavelength spin and spin-isospin instabilities of nuclear matter, including the unphysical transition to a polarized state in neutron-star matter, are eliminated. Our three interactions are characterized by values of the symmetry coefficient J of 30, 31, and 32 MeV, respectively. The best fit to the database of 2353 nuclear masses is found for model HFB-31 (J =31 MeV ) with a model error of 0.561 MeV. This model also fits the charge-radius data with an root-mean-square error of 0.027 fm.

  18. Extended Structures in RNA Folding Intermediates Are Due to Nonnative Interactions Rather than Electrostatic Repulsion

    SciTech Connect

    Baird, Nathan J.; Gong, Haipeng; Zaheer, Syed S.; Freed, Karl F.; Pan, Tao; Sosnick, Tobin R.

    2010-05-25

    RNA folding occurs via a series of transitions between metastable intermediate states for Mg{sup 2+} concentrations below those needed to fold the native structure. In general, these folding intermediates are considerably less compact than their respective native states. Our previous work demonstrates that the major equilibrium intermediate of the 154-residue specificity domain (S-domain) of the Bacillus subtilis RNase P RNA is more extended than its native structure. We now investigate two models with falsifiable predictions regarding the origins of the extended intermediate structures in the S-domains of the B. subtilis and the Escherichia coli RNase P RNA that belong to different classes of P RNA and have distinct native structures. The first model explores the contribution of electrostatic repulsion, while the second model probes specific interactions in the core of the folding intermediate. Using small-angle X-ray scattering and Langevin dynamics simulations, we show that electrostatics plays only a minor role, whereas specific interactions largely account for the extended nature of the intermediate. Structural contacts in the core, including a nonnative base pair, help to stabilize the intermediate conformation. We conclude that RNA folding intermediates adopt extended conformations due to short-range, nonnative interactions rather than generic electrostatic repulsion of helical domains. These principles apply to other ribozymes and riboswitches that undergo functionally relevant conformational changes.

  19. Genesis and evolution of the Skyrme model from 1954 to the present

    SciTech Connect

    San Yuk, V.I. . Dept. of Physics)

    1992-01-10

    Not widely known facts on the genesis of the Skyrme model are presented in a historical survey, based on Skyrme's earliest papers and on his own published remembrance. This paper considers the evolution of Skyrme's model description of nuclear matter from the Mesonic Fluid model up to its final version, known as the baryon model. We pay special tribute to some well-known ideas in contemporary particle physics which one can find in Skyrme's earlier papers, such as: Nuclear Democracy, the Solitonic Mechanism, the Nonlinear Realization of Chiral Symmetry, Topological Charges, Fermi-Bose Transmutations, etc. It is curious to note in the final version of the Skyrme model gleams of Kelvin's Vortex Atoms theory. In conclusion we make a brief analysis of the validity of Skyrme's conjectures in view of recent results and pinpoint some questions which still remain.

  20. Hairy black holes in the general Skyrme model

    NASA Astrophysics Data System (ADS)

    Adam, C.; Kichakova, O.; Shnir, Ya.; Wereszczynski, A.

    2016-07-01

    We study the existence of hairy black holes in the generalized Einstein-Skyrme model. It is proven that in the Bogomol'nyi-Prasad-Sommerfield model limit there are no hairy black hole solutions, although the model admits gravitating (and flat space) solitons. Furthermore, we find strong evidence that a necessary condition for the existence of black holes with Skyrmionic hair is the inclusion of the Skyrme term L4. As an example, we show that there are no hairy black holes in the L2+L6+L0 model and present a new kind of black hole solutions with compact Skyrmion hair in the L4+L6+L0 model.

  1. Exploration of a modified density dependence in the Skyrme functional

    SciTech Connect

    Erler, J.; Reinhard, P.-G.; Kluepfel, P.

    2010-10-15

    A variant of the basic Skyrme-Hartree-Fock functional is considered dealing with a new form of density dependence. It employs only integer powers and thus will allow a more sound basis for projection schemes (particle number, angular momentum). We optimize the new functional with exactly the same adjustment strategy as used in an earlier study with a standard Skyrme functional. This allows direct comparisons of the performance of the new functional relative to the standard one. We discuss various observables: bulk properties of finite nuclei, nuclear matter, giant resonances, superheavy elements, and energy systematics. The new functional performs at least as well as the standard one, but offers a wider range of applicability (e.g., for projection) and more flexibility in the regime of high densities.

  2. Quantum mass shift of the soliton in the Skyrme model

    SciTech Connect

    Livne, H. )

    1993-02-01

    The quantum mass shift of the soliton in the Skyrme model has been calculated from all nonzero modes. The calculations were carried out using a method applied earlier to the sine-Gordon model. The mass shifts do not depend on the baryonic spin, therefore they are the same for the nucleon and the [Delta]. Our model parameters are the pion decay constant [ital F][sub [pi

  3. Skyrme functional from a three-body pseudopotential of second order in gradients: Formalism for central terms

    NASA Astrophysics Data System (ADS)

    Sadoudi, J.; Duguet, T.; Meyer, J.; Bender, M.

    2013-12-01

    Background: In one way or another, all modern parametrizations of the nuclear energy density functional (EDF) do not respect the exchange symmetry associated with Pauli's principle. It has been recently shown that this practice jeopardizes multireference (MR) EDF calculations by contaminating the energy with spurious self-interactions that, for example, lead to finite steps or even divergences when plotting it as a function of collective coordinates [J. Dobaczewski , Phys. Rev. CPRVCAN0556-281310.1103/PhysRevC.76.054315 76, 054315 (2007); D. Lacroix , Phys. Rev. CPRVCAN0556-281310.1103/PhysRevC.79.044318 79, 044318 (2009)]. As of today, the only viable option to bypass these pathologies is to rely on EDF kernels that enforce Pauli's principle from the outset by strictly and exactly deriving from a genuine, i.e., density-independent, Hamilton operator.Purpose: The objective is to build cutting-edge parametrizations of the EDF kernel deriving from a pseudopotential that can be safely employed in symmetry restoration and configuration mixing calculations.Methods: We wish to develop the most general Skyrme-like EDF parametrization containing linear, bilinear, and trilinear terms in the density matrices with up to two gradients, under the key constraint that it derives strictly from an effective Hamilton operator. While linear and bilinear terms are obtained from a standard one-body kinetic energy operator and a (density-independent) two-body Skyrme pseudopotential, the most general three-body Skyrme-like pseudopotential containing up to two gradient operators is constructed to generate the trilinear part. The present study is limited to central terms. Spin orbit and tensor will be addressed in a forthcoming paper.Results: The most general central Skyrme-type zero-range three-body interaction is built up to second order in derivatives. The complete trilinear EDF, including time-odd and T=1 pairing parts, is derived along with the corresponding normal and anomalous

  4. Physical Origin of Density Dependent Force of the Skyrme Type within the Quark Meson Coupling Model

    SciTech Connect

    Pierre Guichon; Hrayr Matevosyan; N. Sandulescu; Anthony Thomas

    2006-03-17

    A density dependent, effective nucleon-nucleon force of the Skyrme type is derived from the quark-meson coupling model--a self-consistent, relativistic quark level description of nuclear matter. This new formulation requires no assumption that the mean scalar field is small and hence constitutes a significant advance over earlier work. The similarity of the effective interaction to the widely used SkM* force encourages us to apply it to a wide range of nuclear problems, beginning with the binding energies and charge distributions of doubly magic nuclei. Finding impressive results in this conventional arena, we apply the same effective interaction, within the Hartree-Fock-Bogoliubov approach, to the properties of nuclei far from stability. The resulting two neutron drip lines and shell quenching are quite satisfactory. Finally, we apply the relativistic formulation to the properties of dense nuclear matter in anticipation of future application to the properties of neutron stars.

  5. Isolate extended state in the DNA molecular transistor with surface interaction

    NASA Astrophysics Data System (ADS)

    Wang, Le; Qin, Zhi-Jie

    2016-02-01

    The field effect characteristic of a DNA molecular device is investigated in a tight binding model with binary disorder and side site correlation. Using the transfer-matrix method and Landauer-Büttiker theory, we find that the system has isolated extended state that is irrespective of the DNA sequence and can be modulated by the gate voltage. When the gate voltage reaches some proper value, the isolated extended state appears at the Fermi level of the system and the long range charge transport is greatly enhanced. We attribute this phenomenon to the combination of the external field, the surface interaction, and the intrinsic disorder of DNA. The result is a generic feature of the nanowire with binary disorder and surface interaction.

  6. Effect of particle-vibration coupling on single-particle states: A consistent study within the Skyrme framework

    SciTech Connect

    Colo, Gianluca; Bortignon, Pier Francesco; Sagawa, Hiroyuki

    2010-12-15

    We discuss calculations of the single-particle states in magic nuclei, performed within the particle-vibration coupling (PVC) approach by using consistently the Skyrme effective interaction. The vibrations are calculated within fully self-consistent random-phase approximation and the whole interaction is also used in the PVC vertex. Our main emphasis is therefore the discussion of our results in comparison with those in which some approximation is made. The perspectives for improving current density functional theory (DFT) calculations are also addressed.

  7. Exact Coulomb exchange calculations in the Skyrme-Hartree-Fock-BCS framework and tests of the Slater approximation

    SciTech Connect

    Le Bloas, J.; Quentin, P.; Bonneau, L.; Ithnin, J. I. A.

    2011-07-15

    An exact treatment of the Coulomb interaction is performed within the Skyrme-Hartree-Fock/Bardeen-Cooper-Schrieffer approach for even-even nuclei ranging from light to superheavy nuclei. A test of the usual Slater approximation for the exchange part is carried out. The error made on the exchange term of the Coulomb interaction when using this approximation follows two schematic patterns. Beyond a decreasing behavior when increasing the mass number A, a more important structural effect has been found. The relative error ranges roughly from 0 to 8% being maximal for light closed proton (sub-)shell nuclei and minimal for open proton (sub-)shell nuclei.

  8. Ground state and excitations of the supersymmetric extended Hubbard model with long-range interaction

    SciTech Connect

    Wang, D.F.; Liu, J.T.

    1996-07-01

    We examine the ground state and excitations of the one-dimensional supersymmetric extended Hubbard model with long-range interaction. The ground state wave-function and low lying excitations are given explicitly in the form of a Jastrow product of two-body terms. This result motivates an asymptotic Bethe ansatz solution for the model. We present evidence that this solution is in fact exact and spans the complete spectrum of states. {copyright} {ital 1996 The American Physical Society.}

  9. Causal dynamical triangulation with extended interactions in 1+1 dimensions

    NASA Astrophysics Data System (ADS)

    Fuji, Hiroyuki; Sato, Yuki; Watabiki, Yoshiyuki

    2011-10-01

    We study the Causal Dynamical Triangulation (CDT) with extended interactions in 1 + 1 dimensions applying the method in the non-critical String Field Theory (SFT) constructed by Ishibashi and Kawai. For this model, we solve Schwinger-Dyson's Equation (SDE) for disk amplitude perturbatively, and find a matrix model in the continuum limit reproducing the SDE in the non-critical SFT approach as the loop equation.

  10. Entanglement and quantum-classical crossover in the extended XX model with long-range interactions

    NASA Astrophysics Data System (ADS)

    Campelo, M. W. V.; de Lima, J. P.; Gonçalves, L. L.

    2013-02-01

    In this work we considered the one-dimensional extended isotropic XY model (s=1/2) in a transverse field with uniform long-range interactions among the z components of the spins. We studied the classical critical behaviour of the model through the behaviour of the magnetization, isothermal susceptibility, internal energy and specific heat. We have obtained exact expressions for these functions and evaluated the critical exponents. The phase diagrams for the classical critical behaviour were built for three cases of the multiplicity p of the multiple spin interaction, namely p=2, p=3 and p→∞. We have also shown that the quantum phase transitions can also be characterized through two quantifiers of entanglement, namely, the concurrence and the von Neumann entropy. We have also verified through the von Neumann entropy how the central charge of the model is affected by the multiplicity p, the coupling exchange J2 and the uniform long-range interaction I.

  11. The Analytical Parametrization of Fusion Barrier by Using the Skyrme Energy-Density Function Model

    NASA Astrophysics Data System (ADS)

    Zanganeh, V.; Mirzaei, M.; N., Wang

    2015-08-01

    Using the skyrme energy density formalism, a pocket formula is introduced for barrier heights and positions of 95 fusion reactions (48 ≤ ZP ZT ≤ 1520) with respect to the charge and mass numbers of the interacting nuclei. It is shown that the parameterized values of RB and VB are able to reproduce the corresponding experimental data with good accuracy. Moreover, the absolute errors of our formulas are less than those obtained using the analytical parametrization forms of the fusion barrier based on the proximity versions. The ability of the parameterized forms of the barrier heights and its positions to reproduce the experimental data of the fusion cross section have been analyzed using the Wong model.

  12. Systematics of the First 2{sup +} Excitation in Spherical Nuclei with Skyrme-QRPA

    SciTech Connect

    Terasaki, J.

    2009-05-07

    We use the Quasiparticle Random Phase Approximation (QRPA) and the Skyrme interactions SLy4 and SkM* to systematically calculate energies and transition strengths for the lowest 2{sup +} state in spherical even-even nuclei. The SkM* functional, applied to 178 spherical nuclei between Z = 10 and 90, produces excitation energies that are on average 11% higher than experimental values, with residuals that fluctuate about the average by -35%+55%. The predictions of SkM* and SLy4 have significant differences, in part because of differences in the calculated ground state deformations; SkM* performs better in both the average and dispersion of energies. Comparing the QRPA results with those of generator-coordinate-method (GCM) calculations, we find that the QRPA reproduces trends near closed shells better than the GCM, and overpredicts the energies less severely in general.

  13. Axially deformed solution of the Skyrme Hartree Fock Bogolyubov equations using the transformed harmonic oscillator basis. The program HFBTHO (v1.66p)

    NASA Astrophysics Data System (ADS)

    Stoitsov, M. V.; Dobaczewski, J.; Nazarewicz, W.; Ring, P.

    2005-04-01

    We describe the program HFBTHO for axially deformed configurational Hartree-Fock-Bogolyubov calculations with Skyrme-forces and zero-range pairing interaction using Harmonic-Oscillator and/or Transformed Harmonic-Oscillator states. The particle-number symmetry is approximately restored using the Lipkin-Nogami prescription, followed by an exact particle number projection after the variation. The program can be used in a variety of applications, including systematic studies of wide ranges of nuclei, both spherical and axially deformed, extending all the way out to nucleon drip lines. Program summaryTitle of the program: HFBTHO (v1.66p) Catalogue number: ADUI Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADUI Licensing provisions: none Computers on which the program has been tested: Pentium-III, Pentium-IV, AMD-Athlon, IBM Power 3, IBM Power 4, Intel Xeon Operating systems: LINUX, Windows Programming language used: FORTRAN-95 Memory required to execute with typical data: 59 MB when using N=20 No. of bits in a word: 64 No. of processors used: 1 Has the code been vectorized?: No No. of bytes in distributed program, including test data, etc.: 195 285 No. of lines in distributed program: 12 058 Distribution format: tar.gz Nature of physical problem: The solution of self-consistent mean-field equations for weakly bound paired nuclei requires a correct description of the asymptotic properties of nuclear quasiparticle wave functions. In the present implementation, this is achieved by using the single-particle wave functions of the Transformed Harmonic Oscillator, which allows for an accurate description of deformation effects and pairing correlations in nuclei arbitrarily close to the particle drip lines. Method of solution: The program uses the axially Transformed Harmonic Oscillator (THO) single-particle basis to expand quasiparticle wave functions. It iteratively diagonalizes

  14. Extending plasma transport theory to strong coupling through the concept of an effective interaction potential

    SciTech Connect

    Baalrud, Scott D.; Daligault, Jérôme

    2014-05-15

    A method for extending traditional plasma transport theories into the strong coupling regime is presented. Like traditional theories, this is based on a binary scattering approximation, but where physics associated with many body correlations is included through the use of an effective interaction potential. The latter is simply related to the pair-distribution function. Modeling many body effects in this manner can extend traditional plasma theory to orders of magnitude stronger coupling. Theoretical predictions are tested against molecular dynamics simulations for electron-ion temperature relaxation as well as diffusion in one component systems. Emphasis is placed on the connection with traditional plasma theory, where it is stressed that the effective potential concept has precedence through the manner in which screening is imposed. The extension to strong coupling requires accounting for correlations in addition to screening. Limitations of this approach in the presence of strong caging are also discussed.

  15. beta. -Decay in the Skyrme-Witten representation of QCD

    SciTech Connect

    Snyderman, N.J.

    1991-05-01

    The renormalized coupling strength of the {beta}-decay axial vector current is related to {pi}{plus minus} p cross sections through the Adler-Weisberger sum rule, that follows from chiral symmetry. We attempt to understand the Adler-Weisberger sum rule in the 1/N{sub c} expansion in QCD, and in the Skyrme-Witten model that realizes the 1/N{sub c} expansion in the low energy limit, using it to explicitly calculate both g{sub A} and the {pi}{plus minus} p cross sections. 32 refs.

  16. Time evolution of initial states that extend beyond the potential interaction region in quantum decay

    NASA Astrophysics Data System (ADS)

    García-Calderón, Gastón; Villavicencio, Jorge; Hernández-Maldonado, Alberto; Romo, Roberto

    2016-08-01

    We investigate the decay of initial states that possess a tail that extends beyond the interaction potential region, for potentials of arbitrary shape that vanish exactly after a distance. This is the case for a relevant class of artificial quantum structures. We obtain that along the internal interaction region, the time evolution of the decaying wave function is formed by two terms. The first one refers to the proper decay of the internal portion of the initial state, whereas the second one, that arises from the external tail, yields a transient contribution that tunnels into the internal region, builds up to a value, and then decays. We obtain that depending on the parameters of the initial state, the nonexponential tail decaying contribution may be larger than the contribution of the proper nonexponential term. These results are illustrated by an exactly solvable model and the Heidelberg potential for decay of ultracold atoms and open the possibility to control initial states in artificial decaying systems.

  17. Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. XV: The spin-orbit coupling

    NASA Astrophysics Data System (ADS)

    Goriely, S.

    2015-01-01

    We construct two new Hartree-Fock-Bogoliubov mass models, labeled HFB-28, HFB-29, which in addition to the generalized Skyrme form containing t4 and t5 terms, also include now a modified spin-orbit force. This alternative spin-orbit force allows for an unconventional isospin and/or density dependence relative to the traditional form included in Skyrme functionals. The new forces underlying these models are fitted to essentially all mass data and at the same time to a realistic equation of state of neutron matter. The inclusion of the modified spin-orbit terms allows us to reduce the rms deviation with respect to all the 2353 known masses with Z, N ≥ 8 by 20 keV, leading to a final model error of 0.52 MeV. It is shown that the newly optimized spin-orbit forces do not conform with the one deduced from the relativistic mean field theory, and consequently that the relativistic spin-orbit force might not be optimum to reproduce experimental masses. The spin-orbit splittings are shown to be reduced and in better agreement with empirical values when including a density-dependent form of the spin-orbit interaction. However, the new mass models with such modified spin-orbit terms still fail to reproduce the kink seen in the isotopic shift of the K or Pb charge radii around the neutron magic numbers, despite the fact that such generalizations of the spin-orbit terms were also introduced to improve the description of the isotopic shifts. Shell effects, in particular far away from stability, are shown to remain unaffected by the new spin-orbit terms, except at the N = 184 magic number.

  18. Quantum mass shift of the soliton in the Skyrme model

    NASA Astrophysics Data System (ADS)

    Livne, Hillel

    1993-02-01

    The quantum mass shift of the soliton in the Skyrme model has been calculated from all nonzero modes. The calculations were carried out using a method applied earlier to the sine-Gordon model. The mass shifts do not depend on the baryonic spin, therefore they are the same for the nucleon and the Δ. Our model parameters are the pion decay constant Fπ, with its experimental value, and the pionic mass mπ, once in the chiral limit mπ=0 and also with the experimental value. We justify taking for the Skyrme parameter e the experimental value of gρππ, the mesonic ρ-pion coupling constant. The results depend on the vibrational energy. In this case an energy cutoff must be introduced. Using renormalization considerations as in the nonlinear σ model, we have chosen this cutoff to be eFπ=1136 MeV. Our results (for e=gρππ=6.11 and Fπ=186 MeV) are MN=996 MeV, MΔ=1593 MeV for mπ=0 MN=857 MeV, MΔ=1641 MeV for mπ=138 MeV. The spin dependence and the energy contribution of the coupling term between vibrations and rotations are being considered here only in a qualitative way.

  19. A Skyrme-like model with an exact BPS bound

    NASA Astrophysics Data System (ADS)

    Ferreira, L. A.; Zakrzewski, Wojtek J.

    2013-09-01

    We propose a new Skyrme-like model with fields taking values on the sphere S 3 or, equivalently, on the group SU(2). The action of the model contains a quadratic kinetic term plus a quartic term which is the same as that of the Skyrme-Faddeev model. The novelty of the model is that it possess a first order Bogomolny type equation whose solutions automatically satisfy the second order Euler-Lagrange equations. It also possesses a lower bound on the static energy which is saturated by the Bogomolny solutions. Such Bogomolny equation is equivalent to the so-called force free equation used in plasma and solar Physics, and which possesses large classes of solutions. An old result due to Chandrasekhar prevents the existence of finite energy solutions for the force free equation on the entire three-dimensional space . We construct new exact finite energy solutions to the Bogomolny equations for the case where the space is the three-sphere S 3, using toroidal like coordinates.

  20. Interacting Thin Film Systems Probed by Electron Induced Extended Fine Structure

    NASA Astrophysics Data System (ADS)

    Idzerda, Yves Ulrich

    In order to obtain information on the structure and dynamics of various systems including interacting thin films, it is necessary to be able to measure local structure information with surface sensitivity. Three techniques of Electron Induced Extended Fine Structure (EIEFS), the electron analog of Extended X-ray Absorption Fine Structure (EXAFS), are described, compared, and applied to thin film systems. Surface Extended Electron Loss Fine Structure (SEELFS), Extended Appearence Potential Fine Structure (EAPFS) and Auger-Monitored Extended Fine Structure (AMEFS), are all local structure probes with varying degrees of surface sensitivity, and all yield similar information. Our results show that each technique can be measured by commercially available electron optics, SEELFS and AMEFS by either a cylindrical mirror analyzer (CMA) or by low energy electron diffraction (LEED) optics and EAPFS by the LEED optics. We have addressed questions concerning proper phase shifts for the analysis, short data ranges, required use of undifferentiated data, and experimental difficulties. Investigations of carbon, oxygen, sodium, potassium, cesium, and sulfur on Cu(111) and titanium on silicon demonstrate that SEELFS is applicable to single monolayer coverages of very low Z adsorbates and thin films. Many of the theoretical difficulties surrounding the analysis of SEELFS can be circumvented by the use of standards and the ratio technique analysis developed for EXAFS. We also find in our studies of silicon, titanium, and aluminum oxide that systems with plasmon losses in the region of interest cannot be analyzed, but systems with other characteristic losses which are very sharp or very broad can be. Examination of EAPFS shows that it is more surface sensitive and is applicable to single monolayer coverages (of a broader range of elements than SEELFS) and thin films. Unfortunately, EAPFS is not applicable to single crystal systems with low electron binding energies where diffraction

  1. Interactive Visualization of 3-D Mantle Convection Extended Through AJAX Applications

    NASA Astrophysics Data System (ADS)

    McLane, J. C.; Czech, W.; Yuen, D.; Greensky, J.; Knox, M. R.

    2008-12-01

    We have designed a new software system for real-time interactive visualization of results taken directly from large-scale simulations of 3-D mantle convection and other large-scale simulations. This approach allows for intense visualization sessions for a couple of hours as opposed to storing massive amounts of data in a storage system. Our data sets consist of 3-D data for volume rendering with over 10 million unknowns at each timestep. Large scale visualization on a display wall holding around 13 million pixels has already been accomplished with extension to hand-held devices, such as the OQO and Nokia N800 and recently the iPHONE. We are developing web-based software in Java to extend the use of this system across long distances. The software is aimed at creating an interactive and functional application capable of running on multiple browsers by taking advantage of two AJAX-enabled web frameworks: Echo2 and Google Web Toolkit. The software runs in two modes allowing for a user to control an interactive session or observe a session controlled by another user. Modular build of the system allows for components to be swapped out for new components so that other forms of visualization could be accommodated such as Molecular Dynamics in mineral physics or 2-D data sets from lithospheric regional models.

  2. Preliminary Model for the Solar Wind Interaction with Pluto's Extended Plasma Tail

    NASA Astrophysics Data System (ADS)

    Sillanpää, I.; Ebert, R.; Elliott, H.; Kallio, E.

    2012-04-01

    We are developing a hybrid model of the Pluto plasma environment (HYB-Pluto) to study the solar wind interaction with Pluto's plasma tail to distances of 1000 Pluto radii (RP) while still resolving the shock and/or wave features upstream of Pluto with good resolution. The HYB-Pluto model features an extended domain and adaptable grid structure along with important processes such as ion-neutral interactions. We present results from our first simulations with the HYB-Pluto model that used realistic values for the solar wind bulk properties and included He++ ions. The results show the formation of a bow shock upstream of Pluto as well as asymmetries of ion density and bow shock in the direction of the convection electric field. This model, along with other current models [1], will provide tools to interpret and understand the plasma observations obtained during expected encounter of the New Horizons spacecraft with the Pluto system in July 2015. [1] P.A. Delamere, Hybrid Code Simulations of the Solar Wind Interaction with Pluto, J. Geophys. Res., 114, A03220, doi:10.1029/2008JA013756, 2009.

  3. Design of a C-band relativistic extended interaction klystron with coaxial output cavity

    NASA Astrophysics Data System (ADS)

    Yang, Wu; Zhao, De-Kui; Chen, Yong-Dong

    2015-07-01

    In order to overcome the disadvantages of conventional high frequency relativistic klystron amplifiers in power capability and RF conversion efficiency, a C-band relativistic extended interaction klystron amplifier with coaxial output cavity is designed with the aid of PIC code MAGIC. In the device, disk-loaded cavities are introduced in the input and intermediate cavity to increase the beam modulation depth, and a coaxial disk-loaded cavity is employed in the output cavity to enhance the RF conversion efficiency. In PIC simulation, when the beam voltage is 680 kV and current is 4 kA, the device can generate 1.11 GW output power at 5.64 GHz with an efficiency of 40.8%.

  4. Mapping and Modeling the Extended Winds of the Massive Interacting Binary, Eta Carinae

    NASA Technical Reports Server (NTRS)

    Gull, Ted

    2010-01-01

    The combination HST/STIS high spatial and moderate spectral resolutions have revealed the massive interacting wind structure of Eta Carinae by forbidden lines of singly and doubly ionized elements. Throughout the 5.54-year period, lines of Fe++, Ne++, Ar++, S++ and N+ reveal the interacting wind structures, near critical electron densities of 10(exp 5) to 3 x 10(exp 7)cu cm, photoionized by the hot secondary, Eta Car B, Lines of Fe+ and Ni+ trace the denser (>10(exp 7)cu cm. less-ionized (< 8 eV) primary wind of Eta Car A as it wraps around the interacting binary stars. For 5 years of the 5.54 year period, the FUV radiation from Eta Car B escapes the orbital region, ionizing the boundaries of the expanding wind structures. But for three to six months, Eta Car B plunges into the primary wind approaching to within 1 to 2 AU, leading to cutoff of FUV and X-ray fluxes. The interacting wind structure, resolved out to 0.8", drops io ionization and then rebuilds as Eta Car B emerges from the primary wind envelope. Solid Particle Hydrodynamical(SPH) models have been developed extending out to 2000 AU and adapted to include FUV radiation effects of the winds. In turn, synthetic spectroimages of selected forbidden lines have been constructed and compared to the spectroimages recorded by the HST/STIS throughout 1998.0 to 2004.3, extending across the 1998 and 2003.5 minima. By this method, we show that the orbital axis of the binary system must bc within 15 degrees of the Homunculus axis of symmetry and that periastron occurs with Eta Car B passing on the far side of Eta Car B. This result ties the current binary orbit with the bipolar ejection with intervening skirt and leads to implications that the binary system influenced the mass ejection of the l840s and the lesser ejection of the 1890s.

  5. MetaSee: An Interactive and Extendable Visualization Toolbox for Metagenomic Sample Analysis and Comparison

    PubMed Central

    Song, Baoxing; Su, Xiaoquan; Xu, Jian; Ning, Kang

    2012-01-01

    The NGS (next generation sequencing)-based metagenomic data analysis is becoming the mainstream for the study of microbial communities. Faced with a large amount of data in metagenomic research, effective data visualization is important for scientists to effectively explore, interpret and manipulate such rich information. The visualization of the metagenomic data, especially multi-sample data, is one of the most critical challenges. The different data sample sources, sequencing approaches and heterogeneous data formats make robust and seamless data visualization difficult. Moreover, researchers have different focuses on metagenomic studies: taxonomical or functional, sample-centric or genome-centric, single sample or multiple samples, etc. However, current efforts in metagenomic data visualization cannot fulfill all of these needs, and it is extremely hard to organize all of these visualization effects in a systematic manner. An extendable, interactive visualization tool would be the method of choice to fulfill all of these visualization needs. In this paper, we have present MetaSee, an extendable toolbox that facilitates the interactive visualization of metagenomic samples of interests. The main components of MetaSee include: (I) a core visualization engine that is composed of different views for comparison of multiple samples: Global view, Phylogenetic view, Sample view and Taxa view, as well as link-out for more in-depth analysis; (II) front-end user interface with real metagenomic models that connect to the above core visualization engine and (III) open-source portal for the development of plug-ins for MetaSee. This integrative visualization tool not only provides the visualization effects, but also enables researchers to perform in-depth analysis of the metagenomic samples of interests. Moreover, its open-source portal allows for the design of plug-ins for MetaSee, which would facilitate the development of any additional visualization effects. PMID:23145044

  6. Rotational-vibrational coupling in the BPS Skyrme model of baryons

    NASA Astrophysics Data System (ADS)

    Adam, C.; Naya, C.; Sanchez-Guillen, J.; Wereszczynski, A.

    2013-11-01

    We calculate the rotational-vibrational spectrum in the BPS Skyrme model for the hedgehog skyrmion with baryon number one. The resulting excitation energies for the nucleon and delta Roper resonances are slightly above their experimental values. Together with the fact that in the standard Skyrme model these excitation energies are significantly lower than the experimental ones, this provides strong evidence for the conjecture that the inclusion of the BPS Skyrme model is required for a successful quantitative description of physical properties of baryons and nuclei.

  7. EXTENDED Ly{alpha} EMISSION FROM INTERACTING GALAXIES AT HIGH REDSHIFTS

    SciTech Connect

    Yajima, Hidenobu; Li Yuexing; Zhu Qirong

    2013-08-20

    Recent observations have discovered a population of extended Ly{alpha} sources, dubbed Ly{alpha} blobs (LABs), at high redshift z {approx} 2-6.6. These LABs typically have a luminosity of L {approx} 10{sup 42}-10{sup 44} erg s{sup -1}, and a size of tens of kiloparsecs, with some giant ones reaching up to D {approx} 100 kpc. However, the origin of these LABs is not well understood. In this paper, we investigate a merger model for the formation of LABs by studying Ly{alpha} emission from interacting galaxies at high redshifts by means of a combination of hydrodynamics simulations with three-dimensional radiative transfer calculations. Our galaxy simulations focus on a set of binary major mergers of galaxies with a mass range of 3-7 Multiplication-Sign 10{sup 12} M{sub Sun} in the redshift range z {approx} 3-7, and we use the newly improved ART{sup 2} code to perform the radiative transfer calculations, which couple multi-wavelength continuum, ionization of hydrogen, and Ly{alpha} line emission. We find that intense star formation and enhanced cooling induced by gravitational interaction produce strong Ly{alpha} emission from these merging galaxies. The Ly{alpha} emission appears to be extended due to the extended distribution of sources and gas. During the close encounter of galaxy progenitors when the star formation rate peaks at {approx}10{sup 3} M{sub Sun} yr{sup -1}, our model produces LABs with luminosity of L {approx} 10{sup 42}-10{sup 44} erg s{sup -1}, and size of D {approx} 10-20 kpc at z > 6 and D {approx} 20-50 kpc at z {approx} 3, in broad agreement with observations in the same redshift range. Our results suggest that merging galaxies may produce some typical LABs as observed, but the giant ones may be produced by mergers more massive than those in our model, or a combination of mergers and cold accretion from filaments on a large scale.

  8. Roles of urea and TMAO on the interaction between extended non-polar peptides

    NASA Astrophysics Data System (ADS)

    Su, Zhaoqian; Dias, Cristiano

    Urea and trimethylamine n-oxide (TMAO) are small molecules known to destabilize and stabilize, respectively, the structure of proteins when added to aqueous solution. To unravel the molecular mechanisms of these cosolvents on protein structure we perform explicit all-atom molecular dynamics simulations of extended poly-alanine and polyleucine dimers. We use an umbrella sampling protocol to compute the potential of mean force (PMF) of dimers at different concentrations of urea and TMAO. We find that the large non-polar side chain of leucine is affected by urea whereas backbone atoms and alanine's side chain are not. Urea is found to occupy positions between leucine's side chains that are not accessible to water. This accounts for extra Lennard-Jones bonds between urea and side chains that favors the unfolded state. These bonds compete with urea-solvent interactions that favor the folded state. The sum of these two energetic terms provide the enthalpic driving force for unfolding. We show here that this enthalpy correlate with the potential of mean force of poly-leucine dimers. Moreover, the framework developed here is general and may be used to provide insights into effects of other small molecules on protein interactions. The effect of the TMAO will be in the presentation. Department of Physics, University Heights, Newark, New Jersey, 07102-1982.

  9. Extended Bose Hubbard model of interacting bosonic atoms in optical lattices: From superfluidity to density waves

    SciTech Connect

    Mazzarella, G.; Giampaolo, S. M.; Illuminati, F.

    2006-01-15

    For systems of interacting, ultracold spin-zero neutral bosonic atoms, harmonically trapped and subject to an optical lattice potential, we derive an Extended Bose Hubbard (EBH) model by developing a systematic expansion for the Hamiltonian of the system in powers of the lattice parameters and of a scale parameter, the lattice attenuation factor. We identify the dominant terms that need to be retained in realistic experimental conditions, up to nearest-neighbor interactions and nearest-neighbor hoppings conditioned by the on-site occupation numbers. In the mean field approximation, we determine the free energy of the system and study the phase diagram both at zero and at finite temperature. At variance with the standard on site Bose Hubbard model, the zero-temperature phase diagram of the EBH model possesses a dual structure in the Mott insulating regime. Namely, for specific ranges of the lattice parameters, a density wave phase characterizes the system at integer fillings, with domains of alternating mean occupation numbers that are the atomic counterparts of the domains of staggered magnetizations in an antiferromagnetic phase. We show as well that in the EBH model, a zero-temperature quantum phase transition to pair superfluidity is, in principle, possible, but completely suppressed at the lowest order in the lattice attenuation factor. Finally, we determine the possible occurrence of the different phases as a function of the experimentally controllable lattice parameters.

  10. Exact solutions to a spatially extended model of kinase-receptor interaction

    NASA Astrophysics Data System (ADS)

    Szopa, Piotr; Lipniacki, Tomasz; Kazmierczak, Bogdan

    2011-10-01

    B and Mast cells are activated by the aggregation of the immune receptors. Motivated by this phenomena we consider a simple spatially extended model of mutual interaction of kinases and membrane receptors. It is assumed that kinase activates membrane receptors and in turn the kinase molecules bound to the active receptors are activated by transphosphorylation. Such a type of interaction implies positive feedback and may lead to bistability. In this study we apply the Steklov eigenproblem theory to analyze the linearized model and find exact solutions in the case of non-uniformly distributed membrane receptors. This approach allows us to determine the critical value of receptor dephosphorylation rate at which cell activation (by arbitrary small perturbation of the inactive state) is possible. We found that cell sensitivity grows with decreasing kinase diffusion and increasing anisotropy of the receptor distribution. Moreover, these two effects are cooperating. We showed that the cell activity can be abruptly triggered by the formation of the receptor aggregate. Since the considered activation mechanism is not based on receptor crosslinking by polyvalent antigens, the proposed model can also explain B cell activation due to receptor aggregation following binding of monovalent antigens presented on the antigen presenting cell.

  11. Toroidal Superheavy Nuclei in Skyrme-Hartree-Fock Approach

    SciTech Connect

    Staszczak, A.; Wong, Cheuk-Yin

    2009-01-01

    Within the self-consistent constraint Skyrme-Hartree-Fock+BCS model (SHF+BCS), we found equilibrium toroidal nuclear density distributions in the region of superheavy elements. For nuclei with a sufficient oblate deformation (Q_{20} < -200 b), it becomes energetically favorable to change the genus of nuclear surface from 0 to 1, i.e., to switch the shape from a biconcave disc to a torus. The energy of the toroidal (genus=1) SHF+BCS solution relative to the compact (genus=0) ground state energy is strongly dependent both on the atomic number Z and the mass number A. We discuss the region of Z and A where the toroidal SHF+BCS total energy begins to be a global minimum.

  12. Skyrme-Maxwell solitons in 2+1 dimensions

    SciTech Connect

    Gladikowski, J.; Piette, B.M.; Schroers, B.J.

    1996-01-01

    A gauged (2+1)-dimensional version of the Skyrme model is investigated. The gauge group is U(1) and the dynamics of the associated gauge potential is governed by a Maxwell term. In this model there are topologically stable soliton solutions carrying magnetic flux which is not topologically quantized. The properties of static, rotationally symmetric solitons of degree one and two are discussed in detail. It is shown that the electric field of such solutions is necessarily zero. The solitons{close_quote} shape, mass, and magnetic flux depend on the U(1) coupling constant, and this dependence is studied numerically from very weak to very strong coupling. {copyright} {ital 1996 The American Physical Society.}

  13. Topological phase transitions in the gauged BPS baby Skyrme model

    NASA Astrophysics Data System (ADS)

    Adam, C.; Naya, C.; Romanczukiewicz, T.; Sanchez-Guillen, J.; Wereszczynski, A.

    2015-05-01

    We demonstrate that the gauged BPS baby Skyrme model with a double vacuum potential allows for phase transitions from a non-solitonic to a solitonic phase, where the latter corresponds to a ferromagnetic liquid. Such a transition can be generated by increasing the external pressure P or by turning on an external magnetic field H. As a consequence, the topological phase where gauged BPS baby skyrmions exist, is a higher density phase. For smaller densities, obtained for smaller values of P and H, a phase without solitons is reached. We find the critical line in the P, H parameter space. Furthermore, in the soliton phase, we find the equation of state for the baby skyrmion matter V = V( P,H) at zero temperature, where V is the "volume", i.e., area of the solitons.

  14. A new Skyrme energy density functional for a better description of spin-isospin resonances

    SciTech Connect

    Roca-Maza, X.; Colò, G.; Cao, Li-Gang; Sagawa, H.

    2015-10-15

    A correct determination of the isospin and spin-isospin properties of the nuclear effective interaction should lead to an accurate description of the Gamow-Teller resonance (GT), the Spin Dipole Resonance (SDR), the Giant Dipole Resonance (GDR) or the Antianalog Giant Dipole Resonance (AGDR), among others. A new Skyrme energy density functional named SAMi is introduced with the aim of going a step forward in setting the bases for a more precise description of spin-isospin resonances [1, 2]. In addition, we will discuss some new features of our analysis on the AGDR in {sup 208}Pb [3] as compared with available experimental data on this resonance [4, 5, 6], and on the GDR [7]. Such study, guided by a simple yet physical pocket formula, has been developed by employing the so called SAMi-J family of systematically varied interactions. This set of interactions is compatible with experimental data for values of the symmetry energy at saturation J and slope parameter L falling in the ranges 31−33 MeV and 75−95 MeV, respectively.

  15. A new Skyrme energy density functional for a better description of spin-isospin resonances

    NASA Astrophysics Data System (ADS)

    Roca-Maza, X.; Colò, G.; Cao, Li-Gang; Sagawa, H.

    2015-10-01

    A correct determination of the isospin and spin-isospin properties of the nuclear effective interaction should lead to an accurate description of the Gamow-Teller resonance (GT), the Spin Dipole Resonance (SDR), the Giant Dipole Resonance (GDR) or the Antianalog Giant Dipole Resonance (AGDR), among others. A new Skyrme energy density functional named SAMi is introduced with the aim of going a step forward in setting the bases for a more precise description of spin-isospin resonances [1, 2]. In addition, we will discuss some new features of our analysis on the AGDR in 208Pb [3] as compared with available experimental data on this resonance [4, 5, 6], and on the GDR [7]. Such study, guided by a simple yet physical pocket formula, has been developed by employing the so called SAMi-J family of systematically varied interactions. This set of interactions is compatible with experimental data for values of the symmetry energy at saturation J and slope parameter L falling in the ranges 31-33 MeV and 75-95 MeV, respectively.

  16. The search for extended infrared emission near interacting and active galaxies

    NASA Technical Reports Server (NTRS)

    Appleton, Philip N.

    1991-01-01

    The following subject areas are covered: the search for extended far IR emission; the search for extended emission in galaxy groups; a brief review of the flattening algorithm; the target groups; extended emission from groups and intergalactic HI clouds; and morphological image processing.

  17. Empathic control through coordinated interaction of amygdala, theory of mind and extended pain matrix brain regions.

    PubMed

    Bruneau, Emile G; Jacoby, Nir; Saxe, Rebecca

    2015-07-01

    Brain regions in the "pain matrix", can be activated by observing or reading about others in physical pain. In previous research, we found that reading stories about others' emotional suffering, by contrast, recruits a different group of brain regions mostly associated with thinking about others' minds. In the current study, we examined the neural circuits responsible for deliberately regulating empathic responses to others' pain and suffering. In Study 1, a sample of college-aged participants (n=18) read stories about physically painful and emotionally distressing events during functional magnetic resonance imaging (fMRI), while either actively empathizing with the main character or trying to remain objective. In Study 2, the same experiment was performed with professional social workers, who are chronically exposed to human suffering (n=21). Across both studies activity in the amygdala was associated with empathic regulation towards others' emotional pain, but not their physical pain. In addition, psychophysiological interaction (PPI) analysis and Granger causal modeling (GCM) showed that amygdala activity while reading about others' emotional pain was preceded by and positively coupled with activity in the theory of mind brain regions, and followed by and negatively coupled with activity in regions associated with physical pain and bodily sensations. Previous work has shown that the amygdala is critically involved in the deliberate control of self-focused distress - the current results extend the central importance of amygdala activity to the control of other-focused empathy, but only when considering others' emotional pain. PMID:25913703

  18. Magnetization plateaus of an easy-axis kagome antiferromagnet with extended interactions

    NASA Astrophysics Data System (ADS)

    Plat, X.; Alet, F.; Capponi, S.; Totsuka, K.

    2015-11-01

    We investigate the properties in finite magnetic field of an extended anisotropic X X Z spin-1/2 model on the kagome lattice, originally introduced by Balents, Fisher, and Girvin [Phys. Rev. B 65, 224412 (2002), 10.1103/PhysRevB.65.224412]. The magnetization curve displays plateaus at magnetization m =1 /6 and 1 /3 when the anisotropy is large. Using low-energy effective constrained models (quantum loop and quantum dimer models), we discuss the nature of the plateau phases, found to be crystals that break discrete rotation and/or translation symmetries. Large-scale quantum Monte Carlo simulations were carried out in particular for the m =1 /6 plateau. We first map out the phase diagram of the effective quantum loop model with an additional loop-loop interaction to find stripe order around the point relevant for the original model as well as a topological Z2 spin liquid. The existence of a stripe crystalline phase is further evidenced by measuring both standard structure factor and entanglement entropy of the original microscopic model.

  19. Interactive computer programs for petrologic modeling with extended Q-mode factor analysis

    USGS Publications Warehouse

    Miesch, A.T.

    1976-01-01

    An extended form of Q-mode factor analysis may be used if the row-sums of the data matrix are constant and can be helpful especially in developing and testing petrologic-mixing models for igneous systems. The first step is to represent the sample compositions as unit vectors in M-dimensional space and then to project them into space of fewer dimensions (m) as determined to be appropriate from a factor-variance diagram. Compositions thought to be those of possible end-members in the petrologic system then are represented as vectors in the M-dimensional space and projected into the same space as the sample vectors. If these vectors remain close to unity in length after projection, the corresponding compositions can serve as end-member compositions for the model. After m suitable end-member compositions have been identified, each sample composition is expressed as a mixture of the end-members by computation of the composition loadings. The interactive computer programs presented are useful in these procedures because of the trial-and-error nature of the modeling procedures. ?? 1976.

  20. Modelling pellet-clad mechanical interaction during extended reduced power operation in bonded nuclear fuel

    NASA Astrophysics Data System (ADS)

    Haynes, T. A.; Ball, J. A.; Shea, J. H.; Wenman, M. R.

    2015-10-01

    A 2D-rӨ model of pellet-clad mechanical interaction in advanced gas-cooled reactor fuel is presented. An incipient 5 μm crack is introduced into the inner surface of cladding bonded to a detachable sliver of fuel. Micro-cracking in the sliver is accounted for through a reduced elastic modulus. A test transient consisting of a hold at 70% power for 720 h was applied to the model. The competing effects of the closure of pellet cracks due to irradiation creep in inner regions of the pellet during extended low power operation, and that of thermal creep in the cladding whilst at reduced power alleviating this are investigated. In colder elements, the effect of irradiation creep dominates. In hotter elements, the effect of cladding creep at low power dominates. It was found that adjusting factors related to the pellet shape were unimportant; the sliver thickness, sliver shape and initial pellet crack width had only a small effect upon the extent of PCMI. Adjusting factors relating to the shape of the incipient crack such as the crack radius and depth had a significant effect; as did adjusting the elastic modulus reduction factor accounting for ladder cracking in the sliver and the coefficient of friction used throughout the model. The resulting model was able to predict the trend in average clad bore crack depth with axial position in the core observed in post irradiation examination.

  1. Extended-soft-core baryon-baryon model. II. Hyperon-nucleon interaction

    SciTech Connect

    Rijken, Th.A.; Yamamoto, Y.

    2006-04-15

    The YN results are presented from the extended soft-core (ESC) interactions. They consist of local and nonlocal potentials because of (i) one-boson exchanges (OBE), which are the members of nonets of pseudoscalar, vector, scalar, and axial mesons; (ii) diffractive exchanges; (iii) two-pseudoscalar exchange; and (iv) meson-pair exchange (MPE). Both the OBE and pair vertices are regulated by Gaussian form factors producing potentials with a soft behavior near the origin. The assignment of the cutoff masses for the baryon-baryon-meson (BBM) vertices is dependent on the SU(3) classification of the exchanged mesons for OBE and a similar scheme for MPE. The particular version of the ESC model, called ESC04 [T. A. Rijken, Phys. Rev. C 73, 044007 (2006)], describes nucleon-nucleon (NN) and hyperon-nucleon (YN) interactions in a unified way using broken SU(3) symmetry. Novel ingredients are the inclusion of (i) the axial-vector meson potentials and (ii) a zero in the scalar- and axial-vector meson form factors. These innovations made it possible for the first time to keep the parameters of the model close to the predictions of the {sup 3}P{sub 0} quark-antiquark creation model. This is also the case for the F/(F+D) ratios. Furthermore, the introduction of the zero helped to avoid the occurrence of unwanted bound states. Broken SU(3) symmetry serves to connect the NN and the YN channels, which leaves after fitting NN only a few free parameters for the determination of the YN interactions. In particular, the meson-baryon coupling constants are calculated via SU(3) using the coupling constants of the NN analysis as input. Here, as a novel feature, medium-strong flavor-symmetry breaking (FSB) of the coupling constants was allowed, using the {sup 3}P{sub 0} model with a Gell-Mann-Okubo hypercharge breaking for the BBM coupling. Very good fits for ESC model with and without FSB were obtained. The charge-symmetry breaking in the {lambda}p and {lambda}n channels, which is an SU(2

  2. Extended-soft-core baryon-baryon model. II. Hyperon-nucleon interaction

    NASA Astrophysics Data System (ADS)

    Rijken, Th. A.; Yamamoto, Y.

    2006-04-01

    The YN results are presented from the extended soft-core (ESC) interactions. They consist of local and nonlocal potentials because of (i) one-boson exchanges (OBE), which are the members of nonets of pseudoscalar, vector, scalar, and axial mesons; (ii) diffractive exchanges; (iii) two-pseudoscalar exchange; and (iv) meson-pair exchange (MPE). Both the OBE and pair vertices are regulated by Gaussian form factors producing potentials with a soft behavior near the origin. The assignment of the cutoff masses for the baryon-baryon-meson (BBM) vertices is dependent on the SU(3) classification of the exchanged mesons for OBE and a similar scheme for MPE. The particular version of the ESC model, called ESC04 [T. A. Rijken, Phys. Rev. C 73, 044007 (2006)], describes nucleon-nucleon (NN) and hyperon-nucleon (YN) interactions in a unified way using broken SU(3) symmetry. Novel ingredients are the inclusion of (i) the axial-vector meson potentials and (ii) a zero in the scalar- and axial-vector meson form factors. These innovations made it possible for the first time to keep the parameters of the model close to the predictions of the 3P0 quark-antiquark creation model. This is also the case for the F/(F+D) ratios. Furthermore, the introduction of the zero helped to avoid the occurrence of unwanted bound states. Broken SU(3) symmetry serves to connect the NN and the YN channels, which leaves after fitting NN only a few free parameters for the determination of the YN interactions. In particular, the meson-baryon coupling constants are calculated via SU(3) using the coupling constants of the NN analysis as input. Here, as a novel feature, medium-strong flavor-symmetry breaking (FSB) of the coupling constants was allowed, using the 3P0 model with a Gell-Mann-Okubo hypercharge breaking for the BBM coupling. Very good fits for ESC model with and without FSB were obtained. The charge-symmetry breaking in the Λp and Λn channels, which is an SU(2) isospin breaking, is included in the

  3. Dynamic Nuclear Polarization enhanced NMR at 187 GHz/284 MHz using an Extended Interaction Klystron amplifier

    NASA Astrophysics Data System (ADS)

    Kemp, Thomas F.; Dannatt, Hugh R. W.; Barrow, Nathan S.; Watts, Anthony; Brown, Steven P.; Newton, Mark E.; Dupree, Ray

    2016-04-01

    A Dynamic Nuclear Polarisation (DNP) enhanced solid-state Magic Angle Spinning (MAS) NMR spectrometer which uses a 187 GHz (corresponding to 1H NMR frequency of 284 MHz) Extended Interaction Klystron (EIK) amplifier as the microwave source is briefly described. Its performance is demonstrated for a biomolecule (bacteriorhodopsin), a pharmaceutical, and surface functionalised silica. The EIK is very compact and easily incorporated into an existing spectrometer. The bandwidth of the amplifier is sufficient that it obviates the need for a sweepable magnetic field, once set, for all commonly used radicals. The variable power (CW or pulsed) output from the EIK is transmitted to the DNP-NMR probe using a quasi-optic system with a high power isolator and a corrugated waveguide which feeds the microwaves into the DNP-NMR probe. Curved mirrors inside the probe project the microwaves down the axis of the MAS rotor, giving a very efficient system such that maximum DNP enhancement is achieved with less than 3 W output from the microwave source. The DNP-NMR probe operates with a sample temperature down to 90 K whilst spinning at 8 kHz. Significant enhancements, in excess of 100 for bacteriorhodopsin in purple membrane (bR in PM), are shown along with spectra which are enhanced by ≈25 with respect to room temperature, for both the pharmaceutical furosemide and surface functionalised silica. These enhancements allow hitherto prohibitively time consuming experiments to be undertaken. The power at which the DNP enhancement in bR in PM saturates does not change significantly between 90 K and 170 K even though the enhancement drops by a factor of ≈11. As the DNP build up time decreases by a factor 3 over this temperature range, the reduction in T1n is presumably a significant contribution to the drop in enhancement.

  4. Dynamic Nuclear Polarization enhanced NMR at 187 GHz/284 MHz using an Extended Interaction Klystron amplifier.

    PubMed

    Kemp, Thomas F; Dannatt, Hugh R W; Barrow, Nathan S; Watts, Anthony; Brown, Steven P; Newton, Mark E; Dupree, Ray

    2016-04-01

    A Dynamic Nuclear Polarisation (DNP) enhanced solid-state Magic Angle Spinning (MAS) NMR spectrometer which uses a 187 GHz (corresponding to (1)H NMR frequency of 284 MHz) Extended Interaction Klystron (EIK) amplifier as the microwave source is briefly described. Its performance is demonstrated for a biomolecule (bacteriorhodopsin), a pharmaceutical, and surface functionalised silica. The EIK is very compact and easily incorporated into an existing spectrometer. The bandwidth of the amplifier is sufficient that it obviates the need for a sweepable magnetic field, once set, for all commonly used radicals. The variable power (CW or pulsed) output from the EIK is transmitted to the DNP-NMR probe using a quasi-optic system with a high power isolator and a corrugated waveguide which feeds the microwaves into the DNP-NMR probe. Curved mirrors inside the probe project the microwaves down the axis of the MAS rotor, giving a very efficient system such that maximum DNP enhancement is achieved with less than 3 W output from the microwave source. The DNP-NMR probe operates with a sample temperature down to 90K whilst spinning at 8 kHz. Significant enhancements, in excess of 100 for bacteriorhodopsin in purple membrane (bR in PM), are shown along with spectra which are enhanced by ≈25 with respect to room temperature, for both the pharmaceutical furosemide and surface functionalised silica. These enhancements allow hitherto prohibitively time consuming experiments to be undertaken. The power at which the DNP enhancement in bR in PM saturates does not change significantly between 90K and 170 K even though the enhancement drops by a factor of ≈11. As the DNP build up time decreases by a factor 3 over this temperature range, the reduction in T1n is presumably a significant contribution to the drop in enhancement. PMID:26867091

  5. Collective nuclear excitations with Skyrme-second random-phase approximation

    SciTech Connect

    Gambacurta, D.; Catara, F.; Grasso, M.

    2010-05-15

    Second random-phase approximation (RPA) calculations with a Skyrme force are performed to describe both high- and low-lying excited states in {sup 16}O. The coupling between one particle-one hole and two particle-two hole as well as that between two particle-two hole configurations among themselves are fully taken into account, and the residual interaction is never neglected; we do not resort therefore to a generally used approximate scheme where only the first kind of coupling is considered. The issue of the rearrangement terms in the matrix elements beyond the standard RPA will be considered in detail in a forthcoming paper. Two approximations are employed here for these rearrangement terms: they are either neglected or evaluated with the RPA procedure. As a general feature of second RPA results, a several-MeV shift of the strength distribution to lower energies is systematically found with respect to RPA distributions. A much more important fragmentation of the strength is also naturally provided by the second RPA owing to the huge number of two particle-two hole configurations. A better description of the excitation energies of the low-lying 0{sup +} and 2{sup +} states is obtained with the second RPA than with the RPA.

  6. Baryons with open beauty dynamically generated from meson-baryon interaction in the extended local hidden gauge approach

    NASA Astrophysics Data System (ADS)

    Liang, Wei-Hong; Xiao, C. W.; Oset, E.

    2016-05-01

    In this talk we review the results about the interaction of B ¯N , B ¯Δ, B ¯*N and B ¯*Δ states with beauty B = 1, together with their coupled channels, using the extended local hidden gauge approach. The Λb(5912) and Λb(5920) observed in the experiment are dynamically generated from the meson-baryon interaction, and they couple mostly to B ¯*N , which are degenerate with the Weinberg-Tomozawa interaction. In addition, three more states with I = 0 and eight more states with I = 1 are predicted.

  7. Systematics of the first 2{sup +} excitation in spherical nuclei with the Skyrme quasiparticle random-phase approximation

    SciTech Connect

    Terasaki, J.; Engel, J.; Bertsch, G. F.

    2008-10-15

    We use the quasiparticle random-phase approximation (QRPA) and the Skyrme interactions SLy4 and SkM* to systematically calculate energies and transition strengths for the lowest 2{sup +} state in spherical even-even nuclei. The SkM* functional, applied to 178 spherical nuclei between Z=10 and 90, produces excitation energies that are on average 11% higher than experimental values, with residuals that fluctuate about the average by -35% to +55%. The predictions of SkM* and SLy4 have significant differences, in part because of differences in the calculated ground state deformations; SkM* performs better in both the average and dispersion of energies. Comparing the QRPA results with those of generator-coordinate-method (GCM) calculations, we find that the QRPA reproduces trends near closed shells better than the GCM, and that it overpredicts the energies less severely in general.

  8. Solitons and black holes in a generalized Skyrme model with dilaton-quarkonium field

    SciTech Connect

    Doneva, Daniela D.; Stefanov, Ivan Zh.; Yazadjiev, Stoytcho S.

    2011-06-15

    Skyrme theory is among the viable effective theories which emerge from the low-energy limit of quantum chromodynamics. Many of its generalizations include also a dilaton. Here we find new self-gravitating solutions, both solitons and black holes, in a generalized Skyrme model in which a dilaton is present. The investigation of the properties of the solutions is done numerically. We find that the introduction of the dilaton in the theory does not change the picture qualitatively, only quantitatively. The model considered here has one free parameter more than the Einstein-Skyrme model which comes from the potential of the dilaton. We have applied also the turning point method to establish that one of the black-hole branches of solutions is unstable. The turning point method here is based on the first law of black-hole thermodynamics a detailed derivation of which is given in the Appendix of the paper.

  9. Applications of Skyrme energy-density functional to fusion reactions for synthesis of superheavy nuclei

    SciTech Connect

    Wang Ning; Scheid, Werner; Wu Xizhen; Liu Min; Li Zhuxia

    2006-10-15

    The Skyrme energy-density functional approach has been extended to study massive heavy-ion fusion reactions. Based on the potential barrier obtained and the parametrized barrier distribution the fusion (capture) excitation functions of a lot of heavy-ion fusion reactions are studied systematically. The average deviations of fusion cross sections at energies near and above the barriers from experimental data are less than 0.05 for 92% of 76 fusion reactions with Z{sub 1}Z{sub 2}<1200. For the massive fusion reactions, for example, the {sup 238}U-induced reactions and {sup 48}Ca+{sup 208}Pb, the capture excitation functions have been reproduced remarkably well. The influence of structure effects in the reaction partners on the capture cross sections is studied with our parametrized barrier distribution. By comparing the reactions induced by double-magic nucleus {sup 48}Ca and by {sup 32}S and {sup 35}Cl, the ''threshold-like'' behavior in the capture excitation function for {sup 48}Ca-induced reactions is explored and an optimal balance between the capture cross section and the excitation energy of the compound nucleus is studied. Finally, the fusion reactions with {sup 36}S, {sup 37}Cl, {sup 48}Ca, and {sup 50}Ti bombarding {sup 248}Cm, {sup 247,249}Bk, {sup 250,252,254}Cf, and {sup 252,254}Es, as well as the reactions leading to the same compound nucleus with Z=120 and N=182, are studied further. The calculation results for these reactions are useful for searching for the optimal fusion configuration and suitable incident energy in the synthesis of superheavy nuclei.

  10. N-soliton interactions in an extended Schrödinger equation with higher order of nonlinearities

    NASA Astrophysics Data System (ADS)

    Yomba, Emmanuel; Zakeri, Gholam-Ali

    2016-02-01

    We investigate the existence of N-solitons in an extended general nonlinear Schrödinger equation with third and fourth order dispersive terms that is most important for applications, such as the dynamics of a general class of anisotropic Heisenberg ferromagnetic spin chain with different magnetic interactions, the alpha helical proteins, and in media that offer interactions in biophysics. We have transformed the model to a homogeneous model that is utilized to show the existence of interactions of N-soliton solutions. We analyzed, and gave specific forms of these new class of N-solitons in a new simple form and discussed the interactions of these N-solitons. We have shown the existence of three types of head-on collisions, head-on collisions with or without over-taking or splitting into two solitons.

  11. Preliminary design and optimization of a G-band extended interaction oscillator based on a pseudospark-sourced electron beam

    SciTech Connect

    Yin, Y. E-mail: yinyong@uestc.edu.cn; He, W.; Zhang, L.; Yin, H.; Cross, A. W.

    2015-07-15

    The design and simulation of a G-band extended interaction oscillator (EIO) driven by a pseudospark-sourced electron beam is presented. The characteristic of the EIO and the pseudospark-based electron beam were studied to enhance the performance of the newly proposed device. The beam-wave interaction of the EIO can be optimized by choosing a suitable pseudospark discharging voltage and by widening the operating voltage region of the EIO circuit. Simulation results show that a peak power of over 240 W can be achieved at G-band using a pseudospark discharge voltage of 41 kV.

  12. Theoretical study on magnetic coupling interaction for Cu(II) binuclear systems with extended bridging groups

    NASA Astrophysics Data System (ADS)

    Bi, Siwei; Liu, Chengbu; Hu, Haiquan; Zhang, Changqiao

    2001-12-01

    The magnetic coupling interaction for Cu(II) binuclear systems with bridging groups C2O4 2- , C2O2( NH) 2 2- ( cis), C2O2( NH) 2 2- ( trans) and C2S2( NH) 2 2- ( trans) was studied by the broken symmetry (BS) approach within the framework of the density functional theory (DFT). The influence of different coordination atoms and geometry on magnetic coupling interaction was theoretically analyzed. Both of the calculated and experimental results were compared. The variation trends of coupling interaction calculated are in agreement with experimental ones.

  13. Extended asymmetric hot region formation due to shockwave interactions following void collapse in shocked high explosive

    DOE PAGESBeta

    Shan, Tzu -Ray; Wixom, Ryan R.; Thompson, Aidan P.

    2016-08-11

    In both continuum hydrodynamics simulations and also multimillion atom reactive molecular dynamics simulations of shockwave propagation in single crystal pentaerythritol tetranitrate (PETN) containing a cylindrical void, we observed the formation of an initial radially symmetric hot spot. By extending the simulation time to the nanosecond scale, however, we observed the transformation of the small symmetric hot spot into a longitudinally asymmetric hot region extending over a much larger volume. Performing reactive molecular dynamics shock simulations using the reactive force field (ReaxFF) as implemented in the LAMMPS molecular dynamics package, we showed that the longitudinally asymmetric hot region was formed bymore » coalescence of the primary radially symmetric hot spot with a secondary triangular hot zone. We showed that the triangular hot zone coincided with a double-shocked region where the primary planar shockwave was overtaken by a secondary cylindrical shockwave. The secondary cylindrical shockwave originated in void collapse after the primary planar shockwave had passed over the void. A similar phenomenon was observed in continuum hydrodynamics shock simulations using the CTH hydrodynamics package. Furthermore, the formation and growth of extended asymmetric hot regions on nanosecond timescales has important implications for shock initiation thresholds in energetic materials.« less

  14. Extended asymmetric hot region formation due to shockwave interactions following void collapse in shocked high explosive

    NASA Astrophysics Data System (ADS)

    Shan, Tzu-Ray; Wixom, Ryan R.; Thompson, Aidan P.

    2016-08-01

    In both continuum hydrodynamics simulations and also multimillion atom reactive molecular dynamics simulations of shockwave propagation in single crystal pentaerythritol tetranitrate (PETN) containing a cylindrical void, we observed the formation of an initial radially symmetric hot spot. By extending the simulation time to the nanosecond scale, however, we observed the transformation of the small symmetric hot spot into a longitudinally asymmetric hot region extending over a much larger volume. Performing reactive molecular dynamics shock simulations using the reactive force field (ReaxFF) as implemented in the LAMMPS molecular dynamics package, we showed that the longitudinally asymmetric hot region was formed by coalescence of the primary radially symmetric hot spot with a secondary triangular hot zone. We showed that the triangular hot zone coincided with a double-shocked region where the primary planar shockwave was overtaken by a secondary cylindrical shockwave. The secondary cylindrical shockwave originated in void collapse after the primary planar shockwave had passed over the void. A similar phenomenon was observed in continuum hydrodynamics shock simulations using the CTH hydrodynamics package. The formation and growth of extended asymmetric hot regions on nanosecond timescales has important implications for shock initiation thresholds in energetic materials.

  15. Straw-thawing method interacts with sire and extender to influence sperm motility and conception rates of dairy cows.

    PubMed

    DeJarnette, J M; Marshall, C E

    2005-11-01

    Influence of interactions of straw-thawing method with sire and extender type (milk or egg yolk-based) on postthaw sperm motility and conception rates of dairy cows was assessed. In experiment 1, sperm from 10 Holstein sires were frozen in egg yolk citrate and heated whole-milk extenders using a split-ejaculate technique. Straws were thawed in a 37 degrees C water bath with or without 3 min of exposure to a 37 degrees C warming plate while wrapped in a paper towel (air-thaw). Percentage of motile sperm was assessed after 1 min and 3 h of incubation at 37 degrees C. In experiment 2, sperm from 3 Holstein sires were frozen in egg-yolk citrate and a nonheated whole milk extender using a split-ejaculate technique. Straws were thawed and motility was assessed as in experiment 1. Conception rates (n = 475) were compared in a single herd of Holstein cows after thawing straws in 35 degrees C water for 45 s or after air-thawing by wiping straws with a paper towel upon removal from the storage vessel and placing directly into the insemination gun. In each experiment, interactions between thaw method and sire, extender type, or both, indicated that conditions may be created that facilitate sperm tolerance of air-thaw procedures. When a significant thaw method effect was detected in either experiment, air-thaw was consistently associated with the lesser measure of sperm motility, conception, or both. In conclusion, although some sire x extender combinations seem to be tolerant of air-thaw procedures, other combinations are more sensitive, resulting in reduced postthaw sperm survival, conception rates of cows, or both, in response to air-thaw. PMID:16230692

  16. Improving intermolecular interactions in DFTB3 using extended polarization from chemical-potential equalization

    SciTech Connect

    Christensen, Anders S. E-mail: cui@chem.wisc.edu; Cui, Qiang E-mail: cui@chem.wisc.edu; Elstner, Marcus

    2015-08-28

    Semi-empirical quantum mechanical methods traditionally expand the electron density in a minimal, valence-only electron basis set. The minimal-basis approximation causes molecular polarization to be underestimated, and hence intermolecular interaction energies are also underestimated, especially for intermolecular interactions involving charged species. In this work, the third-order self-consistent charge density functional tight-binding method (DFTB3) is augmented with an auxiliary response density using the chemical-potential equalization (CPE) method and an empirical dispersion correction (D3). The parameters in the CPE and D3 models are fitted to high-level CCSD(T) reference interaction energies for a broad range of chemical species, as well as dipole moments calculated at the DFT level; the impact of including polarizabilities of molecules in the parameterization is also considered. Parameters for the elements H, C, N, O, and S are presented. The Root Mean Square Deviation (RMSD) interaction energy is improved from 6.07 kcal/mol to 1.49 kcal/mol for interactions with one charged species, whereas the RMSD is improved from 5.60 kcal/mol to 1.73 for a set of 9 salt bridges, compared to uncorrected DFTB3. For large water clusters and complexes that are dominated by dispersion interactions, the already satisfactory performance of the DFTB3-D3 model is retained; polarizabilities of neutral molecules are also notably improved. Overall, the CPE extension of DFTB3-D3 provides a more balanced description of different types of non-covalent interactions than Neglect of Diatomic Differential Overlap type of semi-empirical methods (e.g., PM6-D3H4) and PBE-D3 with modest basis sets.

  17. Correction for solute/solvent interaction extends accurate freezing point depression theory to high concentration range.

    PubMed

    Fullerton, G D; Keener, C R; Cameron, I L

    1994-12-01

    The authors describe empirical corrections to ideally dilute expressions for freezing point depression of aqueous solutions to arrive at new expressions accurate up to three molal concentration. The method assumes non-ideality is due primarily to solute/solvent interactions such that the correct free water mass Mwc is the mass of water in solution Mw minus I.M(s) where M(s) is the mass of solute and I an empirical solute/solvent interaction coefficient. The interaction coefficient is easily derived from the constant in the linear regression fit to the experimental plot of Mw/M(s) as a function of 1/delta T (inverse freezing point depression). The I-value, when substituted into the new thermodynamic expressions derived from the assumption of equivalent activity of water in solution and ice, provides accurate predictions of freezing point depression (+/- 0.05 degrees C) up to 2.5 molal concentration for all the test molecules evaluated; glucose, sucrose, glycerol and ethylene glycol. The concentration limit is the approximate monolayer water coverage limit for the solutes which suggests that direct solute/solute interactions are negligible below this limit. This is contrary to the view of many authors due to the common practice of including hydration forces (a soft potential added to the hard core atomic potential) in the interaction potential between solute particles. When this is recognized the two viewpoints are in fundamental agreement. PMID:7699200

  18. Calmodulin Adopts an Extended Conformation when Interacting with L-Selectin in Membranes

    PubMed Central

    Deng, Wei; Putkey, John A.; Li, Renhao

    2013-01-01

    Calmodulin, an intracellular calcium-binding protein, is thought to regulate ectodomain shedding of many membrane proteins, but the underlying molecular mechanism has remained unclear. Basing on a solution structure of calcium-loaded calmodulin in complex with a L-selectin fragment that contains a portion of its transmembrane domain, Gifford et al. (University of Calgary) recently suggested that calmodulin regulates L-selectin shedding by binding directly to a portion of the L-selectin transmembrane domain in a compact conformation. Using fluorescently labeled calmodulin, we show however that calmodulin adopts a distinctly different and much more extended conformation when it binds to the CLS peptide (i.e. the entire transmembrane and cytoplasmic domains of L-selectin) reconstituted in the phosphatidylcholine liposome with micromolar dissociation constant and in a calcium-independent manner. Calmodulin adopts a similarly extended conformation in a ternary complex with the N-terminal FERM domain of moesin and CLS reconstituted in the phospholipid liposome that mimics the native membrane environment. These results indicate that calmodulin does not bind directly to the transmembrane domain of L-selectin. Understanding the association of calmodulin with L-selectin helps to shed light on the mechanisms underlying regulation of ectodomain shedding. PMID:23658780

  19. Towards the establishment of nonlinear hidden symmetries of the Skyrme model

    SciTech Connect

    Herrera-Aguilar, A.; Kanakoglou, K.; Paschalis, J. E.

    2006-09-25

    We present a preliminary attempt to establish the existence of hidden nonlinear symmetries of the SU(N) Skyrme model which could, in principle, lead to the further integration of the system. An explicit illustration is given for the SU(2) symmetry group.

  20. Symmetry energy from nuclear masses and neutron-star observations using generalised Skyrme functionals

    NASA Astrophysics Data System (ADS)

    Chamel, N.; Fantina, A. F.; Pearson, J. M.; Goriely, S.

    2016-01-01

    We study the constraints imposed by nuclear mass measurements and neutron-star observations on the symmetry energy. For this purpose, we use a family of unified equations of state of neutron-star interiors, based on generalised Skyrme functionals that were fitted to essentially all the experimental nuclear mass data while ensuring a realistic neutron-matter equation of state.

  1. Using 4th order Runge-Kutta method for solving a twisted Skyrme string equation

    NASA Astrophysics Data System (ADS)

    Hadi, Miftachul; Anderson, Malcolm; Husein, Andri

    2016-03-01

    We study numerical solution, especially using 4th order Runge-Kutta method, for solving a twisted Skyrme string equation. We find numerically that the value of minimum energy per unit length of vortex solution for a twisted Skyrmion string is 20.37 × 1060 eV/m.

  2. Outer satellite atmospheres: Their extended nature and planetary interactions. [sodium cloud of Io, hydrogen torus of Titan, and comet atmospheres

    NASA Technical Reports Server (NTRS)

    Smyth, W. H.

    1980-01-01

    Highly developed numerical models are applied to interpret extended-atmosphere data for the sodium cloud of Io and the hydrogen torus of Titan. Solar radiation pressure was identified and verified by model calculations as the mechanism to explain two different east-west asymmetries observed in the sodium cloud. Analysis of sodium line profile data, suggesting that a Jupiter magnetospheric wind may be responsible for high speed sodium atoms emitted from Io, and preliminary modeling of the interaction of the Io plasma torus and Io's sodium cloud are also reported. Models presented for Titan's hydrogen torus are consistent both with the recent Pioneer 11 measurements and earlier Earth-orbiting observations by the Copernicus satellite. Progress is reported on developing models for extended gas and dust atmospheres of comets.

  3. Extended magnetic exchange interactions in the high-temperature ferromagnet MnBi

    NASA Astrophysics Data System (ADS)

    Williams, T. J.; Taylor, A. E.; Christianson, A. D.; Hahn, S. E.; Fishman, R. S.; Parker, D. S.; McGuire, M. A.; Sales, B. C.; Lumsden, M. D.

    2016-05-01

    The high-temperature ferromagnet MnBi continues to receive attention as a candidate to replace rare-earth-containing permanent magnets in applications above room temperature. This is due to a high Curie temperature, large magnetic moments, and a coercivity that increases with temperature. The synthesis of MnBi also allows for crystals that are free of interstitial Mn, enabling more direct access to the key interactions underlying the physical properties of binary Mn-based ferromagnets. In this work, we use inelastic neutron scattering to measure the spin waves of MnBi in order to characterize the magnetic exchange at low temperature. Consistent with the spin reorientation that occurs below 140 K, we do not observe a spin gap in this system above our experimental resolution. A Heisenberg model was fit to the spin wave data in order to characterize the long-range nature of the exchange. It was found that interactions up to sixth nearest neighbor are required to fully parametrize the spin waves. Surprisingly, the nearest-neighbor term is antiferromagnetic, and the realization of a ferromagnetic ground state relies on the more numerous ferromagnetic terms beyond nearest neighbor, suggesting that the ferromagnetic ground state arises as a consequence of the long-ranged interactions in the system.

  4. Extended magnetic exchange interactions in the high-temperature ferromagnet MnBi

    DOE PAGESBeta

    Christianson, Andrew D.; Hahn, Steven E.; Fishman, Randy Scott; Parker, David S.; McGuire, Michael A.; Sales, Brian C.; Lumsden, Mark D.; Williams, T. J.; Taylor, A. E.

    2016-05-09

    Here, the high-temperature ferromagnet MnBi continues to receive attention as a candidate to replace rare-earth-containing permanent magnets in applications above room temperature. This is due to a high Curie temperature, large magnetic moments, and a coercivity that increases with temperature. The synthesis of MnBi also allows for crystals that are free of interstitial Mn, enabling more direct access to the key interactions underlying the physical properties of binary Mn-based ferromagnets. In this work, we use inelastic neutron scattering to measure the spin waves of MnBi in order to characterize the magnetic exchange at low temperature. Consistent with the spin reorientationmore » that occurs below 140~K, we do not observe a spin gap in this system above our experimental resolution. A Heisenberg model was fit to the spin wave data in order to characterize the long-range nature of the exchange. It was found that interactions up to sixth nearest neighbor are required to fully parameterize the spin waves. Surprisingly, the nearest-neighbor term is antiferromagnetic, and the realization of a ferromagnetic ground state relies on the more numerous ferromagnetic terms beyond nearest neighbor, suggesting that the ferromagnetic ground state arises as a consequence of the long-ranged interactions in the system.« less

  5. Extended mathematical model for "in vivo" quantification of the interaction betweeen atazanavir and bilirubin.

    PubMed

    Lozano, Roberto; Domeque, Nieves; Apesteguia, Alberto-Fermín

    2014-02-01

    The objective of the present work was to conduct an "in vivo" analysis of the atazanavir-bilirubin interaction. We developed a new mathematical approach to PK/PDPK models for competitive interaction based on the Michaelis-Menten equation, which was applied to patients with polymorphisms in the gene for UDP-glucuronosyltransferase 1A1 (UGT1A1). Atazanavir is known to induce concentration-dependent increases in bilirubin plasma levels. Thus, we employed our mathematical model to analyse rises in steady state atazanavir and bilirubin concentrations, ultimately plotting a nomogram for detection of suboptimal atazanavir exposure. Application of our model revealed that an absolute value or a steady state increase in bilirubin falling below 3.8Φ µmol/L (where Φ is a correction factor, =1 for UGT1A1 wild type and ≠1 for UGT1A1 variants) could be used to predict suboptimal atazanavir exposure and treatment failure. Thus, we have successfully established a new mathematical approach for pharmacodynamic-pharmacokinetic modelling of the interaction between atazanavir and bilirubin, as it relates to genetic variants of UGT1A1. Taken together, our findings indicate that bilirubin plasma levels represent a valuable marker of atazanavir exposure. PMID:24243081

  6. Interactions and dynamics of two extended conformation adapting phosphatidylcholines in model biomembranes.

    PubMed

    Amirkavei, Mooud; Kinnunen, Paavo K J

    2016-02-01

    In order to obtain molecular level insight into the biophysics of the apoptosis promoting phospholipid 1-palmitoyl-2-azelaoyl-sn-glycero-3-phosphocholine (PazePC) we studied its partitioning into different lipid phases by isothermal titration calorimetry (ITC). To aid the interpretation of these data for PazePC, we additionally characterized by both ITC and fluorescence spectroscopy the fluorescent phospholipid analog 1-palmitoyl-2-{6-[(7-nitro-2-1,3-benzoxadiazol-4-yl)amino]hexanoyl}-sn-glycero-3-phosphocholine (NBD-C6-PC), which similarly to PazePC can adopt extended conformation in lipid bilayers. With the NBD-hexanoyl chain reversing its direction and extending into the aqueous space out of the bilayer, 7-nitro-2,1,3-benzoxadiazol-4-yl (NBD) becomes accessible to the water soluble dithionite, which reduces to non-fluorescent product. Our results suggest that these phospholipid derivatives first partition and penetrate into the outer bilayer leaflet of liquid disordered phase liposomes composed of unsaturated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Upon increase up to 2 mol% PazePC and NBD-C6-PC of the overall content, flip-flop from the outer into the inner bilayer leaflet commences. Interestingly, the presence of 40 mol% cholesterol in POPC liposomes did not abrogate the partitioning of PazePC into the liquid ordered phase. In contrast, only insignificant partitioning of PazePC and NBD-C6-PC into sphingomyelin/cholesterol liposomes was evident, highlighting a specific membrane permeability barrier function of this particular lipid composition against oxidatively truncated PazePC, thus emphasizing the importance of detailed characterization of the biophysical properties of membranes found in different cellular organelles, in terms of providing barriers for lipid-mediated cellular signals in processes such as apoptosis. Our data suggest NBD-C6-PC to represent useful fluorescent probe to study the cellular dynamics of oxidized phospholipid

  7. High flux, narrow bandwidth compton light sources via extended laser-electron interactions

    SciTech Connect

    Barty, V P

    2015-01-13

    New configurations of lasers and electron beams efficiently and robustly produce high flux beams of bright, tunable, polarized quasi-monoenergetic x-rays and gamma-rays via laser-Compton scattering. Specifically, the use of long-duration, pulsed lasers and closely-spaced, low-charge and low emittance bunches of electron beams increase the spectral flux of the Compton-scattered x-rays and gamma rays, increase efficiency of the laser-electron interaction and significantly reduce the overall complexity of Compton based light sources.

  8. Quantum Phase Transitional Behavior in the Extended Casten Triangle of the Interacting Boson Model

    NASA Astrophysics Data System (ADS)

    Pan, Feng; Wang, Tao; Huo, Y.-S.; Draayer, J. P.

    Quantum phase transitional patterns in the whole parameter space of the consistent-Q Hamiltonian in the Interacting Boson Model are studied based on an implemented Fortran code for numerical computation of the matrix elements in the SU(3) Draayer-Akiyama basis. Results with respect to both ground and some excited states of the model Hamiltonian are discussed. Quantum phase transitional behavior under a variety of parameter situations is shown. It is found that transitional behavior of excited states is more complicated. Pt isotopes are taken as examples in illustrating the prolate-oblate shape phase transition.

  9. Interaction between magnetic agglomerates and an extended free radicals network studied by magnetic resonance

    NASA Astrophysics Data System (ADS)

    Guskos, Niko; Zolnierkiewicz, Grzegorz; Typek, Janusz; Guskos, Aleksander; Berczynski, Pawel; Petridis, Dimitri

    2012-02-01

    Solids containing an extended network of free radicals have been prepared and studied by magnetic resonance techniques in the 4-290 K temperature range. One solid contained additionally a small amount of magnetic γ-Fe2O3 in the form of nanoparticle agglomerates. The solid without agglomerates displayed only a narrow, single resonance line centered at g eff = 2.0043. The magnetic resonance measurements of the solid with γ-Fe2O3 agglomerates gave a spectrum composed of two lines attributed to two different magnetic centers: a narrow line due to free radicals and a broad line arising from magnetic iron oxide agglomerates. In the high temperature range the integrated intensities of both lines decreased with decreasing temperature. The resonance field of the broad line shifted to lower magnetic fields upon lowering the temperature with the gradient ΔH r/ΔT = 2.3 G/K, while the narrow line shifted towards higher magnetic fields. The linewidth of the broader line increased with decreasing temperature while for the narrow lines in both samples this change was small. The magnetic iron oxide clusters produce a magnetic field which acts on the free radicals network and its strength depends essentially on the concentration of clusters. The reorientation process in the free radicals network is more intense in the sample without magnetic clusters.

  10. Interaction between magnetic agglomerates and an extended free radicals network studied by magnetic resonance

    NASA Astrophysics Data System (ADS)

    Guskos, Niko; Zolnierkiewicz, Grzegorz; Typek, Janusz; Guskos, Aleksander; Berczynski, Pawel; Petridis, Dimitri

    2012-02-01

    Solids containing an extended network of free radicals have been prepared and studied by magnetic resonance techniques in the 4-290 K temperature range. One solid contained additionally a small amount of magnetic γ-Fe2O3 in the form of nanoparticle agglomerates. The solid without agglomerates displayed only a narrow, single resonance line centered at g eff = 2.0043. The magnetic resonance measurements of the solid with γ-Fe2O3 agglomerates gave a spectrum composed of two lines attributed to two different magnetic centers: a narrow line due to free radicals and a broad line arising from magnetic iron oxide agglomerates. In the high temperature range the integrated intensities of both lines decreased with decreasing temperature. The resonance field of the broad line shifted to lower magnetic fields upon lowering the temperature with the gradient Δ H r /Δ T = 2.3 G/K, while the narrow line shifted towards higher magnetic fields. The linewidth of the broader line increased with decreasing temperature while for the narrow lines in both samples this change was small. The magnetic iron oxide clusters produce a magnetic field which acts on the free radicals network and its strength depends essentially on the concentration of clusters. The reorientation process in the free radicals network is more intense in the sample without magnetic clusters.

  11. LBQ2D, Extending the Line Broadened Quasilinear Model to TAE-EP Interaction

    NASA Astrophysics Data System (ADS)

    Ghantous, Katy; Gorelenkov, Nikolai; Berk, Herbert

    2012-10-01

    The line broadened quasilinear model was proposed and tested on the one dimensional electrostatic case of the bump on tailfootnotetextH.L Berk, B. Breizman and J. Fitzpatrick, Nucl. Fusion, 35:1661, 1995 to study the wave particle interaction. In conventional quasilinear theory, the sea of overlapping modes evolve with time as the particle distribution function self consistently undergo diffusion in phase space. The line broadened quasilinear model is an extension to the conventional theory in a way that allows treatment of isolated modes as well as overlapping modes by broadening the resonant line in phase space. This makes it possible to treat the evolution of modes self consistently from onset to saturation in either case. We describe here the model denoted by LBQ2D which is an extension of the proposed one dimensional line broadened quasilinear model to the case of TAEs interacting with energetic particles in two dimensional phase space, energy as well as canonical angular momentum. We study the saturation of isolated modes in various regimes and present the analytical derivation and numerical results. Finally, we present, using ITER parameters, the case where multiple modes overlap and describe the techniques used for the numerical treatment.

  12. Synthesis, structure, characterization and fluorescent properties of Ag+ complexes with extended π⋯π interactions

    NASA Astrophysics Data System (ADS)

    Huang, Ting-Hong; Yan, Jie; Yang, Hu; Qiang, Liu; Du, Huai-Ming

    2015-12-01

    Two mixed-ligand Ag (I) complexes, [Ag2(Phterpy)2(NO3)2(dppe)]·CH3CN (1) and [Ag4(Phterpy)2(NO3)2(dppp)2](NO3)2·6H2O (2) (dppe = 1, 2-bis (diphenylphosphino) ethane, dppp = 1, 3-bis (diphenylphosphino) propane, Phterpy = 4‧-phenyl-2, 2‧:6‧, 2″-terpyridine), have been synthesized and structurally characterized by IR, 1H-NMR, 31P-NMR, elemental analysis and X-ray crystal structure analysis. Structural analysis reveals that the change of bridging ligands from dppe to dppp lead to the formation of centrosymmetric cations [Ag2(Phterpy)2(NO3)2(dppe)] and [Ag4(Phterpy)2 (NO3)2(dppp)2]2+, especially complex 2 containing two independent centrosymmetric tetramers with the central (obligate) Ag2O2 planes. Complexes 1 and 2 consist of the 1D infinite chains, with different variations in π-stacking patterns. Crystal structure of 1 contains 1D infinite chains constructed by π⋯π interactions between Phterpy, while 2 is built by π⋯π interaction of phenylene rings from dppp. All these reveal that the change of phosphine ligands might be the key of construction of different types of polynuclear structures and 1D π-stacking chain. Moreover, the solid-state emission spectra of complexes 1 and 2 display broad emission bands at 420-600 nm.

  13. Collective Behaviors in Spatially Extended Systems with Local Interactions and Synchronous Updating

    NASA Astrophysics Data System (ADS)

    ChatÉ, H.; Manneville, P.

    1992-01-01

    Assessing the extent to which dynamical systems with many degrees of freedom can be described within a thermodynamics formalism is a problem that currently attracts much attention. In this context, synchronously updated regular lattices of identical, chaotic elements with local interactions are promising models for which statistical mechanics may be hoped to provide some insights. This article presents a large class of cellular automata rules and coupled map lattices of the above type in space dimensions d = 2 to 6.Such simple models can be approached by a mean-field approximation which usually reduces the dynamics to that of a map governing the evolution of some extensive density. While this approximation is exact in the d = infty limit, where macroscopic variables must display the time-dependent behavior of the mean-field map, basic intuition from equilibrium statistical mechanics rules out any such behavior in a low-dimensional systems, since it would involve the collective motion of locally disordered elements.The models studied are chosen to be as close as possible to mean-field conditions, i.e., rather high space dimension, large connectivity, and equal-weight coupling between sites. While the mean-field evolution is never observed, a new type of non-trivial collective behavior is found, at odds with the predictions of equilibrium statistical mechanics. Both in the cellular automata models and in the coupled map lattices, macroscopic variables frequently display a non-transient, time-dependent, low-dimensional dynamics emerging out of local disorder. Striking examples are period 3 cycles in two-state cellular automata and a Hopf bifurcation for a d = 5 lattice of coupled logistic maps. An extensive account of the phenomenology is given, including a catalog of behaviors, classification tables for the celular automata rules, and bifurcation diagrams for the coupled map lattices.The observed underlying dynamics is accompanied by an intrinsic quasi-Gaussian noise

  14. Acid-Base Formalism Extended to Excited State for O-H···S Hydrogen Bonding Interaction.

    PubMed

    Bhattacharyya, Surjendu; Roy, Ved Prakash; Wategaonkar, Sanjay

    2016-09-01

    Hydrogen bond can be regarded as an interaction between a base and a proton covalently bound to another base. In this context the strength of hydrogen bond scales with the proton affinity of the acceptor base and the pKa of the donor, i.e., it follows the acid-base formalism. This has been amply demonstrated in conventional hydrogen bonds. Is this also true for the unconventional hydrogen bonds involving lesser electronegative elements such as sulfur atom? In our previous work, we had established that the strength of O-H···S hydrogen bonding (HB) interaction scales with the proton affinity (PA) of the acceptor. In this work, we have investigated the other counterpart, i.e., the H-bonding interaction between the photoacids with different pKa values with a common base such as the H2O and H2S. The 1:1 complexes of five para substituted phenols p-aminophenol, p-cresol, p-fluorophenol, p-chlorophenol, and p-cyanophenol with H2O and H2S were investigated experimentally and computationally. The investigations were also extended to the excited states. The experimental observations of the spectral shifts in the O-H stretching frequency and the S1-S0 band origins were correlated with the pKa of the donors. Ab initio calculations at the MP2 and various dispersion corrected density functional levels of theory were performed to compute the dissociation energy (D0) of the complexes. The quantum theory of atoms in molecules (QTAIM), noncovalent interaction (NCI) method, natural bonding orbital (NBO) analysis, and natural decomposition analysis (NEDA) were carried out for further characterization of HB interaction. The O-H stretching frequency red shifts and the dissociation energies were found to be lower for the O-H···S hydrogen bonded systems compared to those for the O-H···O H-bound systems. Despite being dominated by the dispersion interaction the O-H···S interaction in the H2S complexes also conformed to the acid-base formalism, i.e., the D0 and the O-H red shift

  15. Collective coordinate quantization and spin statistics of the solitons in the C PN Skyrme-Faddeev model

    NASA Astrophysics Data System (ADS)

    Amari, Yuki; Klimas, Paweł; Sawado, Nobuyuki

    2016-07-01

    The C PN extended Skyrme-Faddeev model possesses planar soliton solutions. We consider quantum aspects of the solutions applying collective coordinate quantization in regime of rigid body approximation. In order to discuss statistical properties of the solutions we include an Abelian Chern-Simons term (the Hopf term) in the Lagrangian. Since Π3(C P1)=Z then for N =1 the term becomes an integer. On the other hand for N >1 it became perturbative because Π3(C PN) is trivial. The prefactor of the Hopf term (anyon angle) Θ is not quantized and its value depends on the physical system. The corresponding fermionic models can fix value of the angle Θ for all N in a way that the soliton with N =1 is not an anyon type whereas for N >1 it is always an anyon even for Θ =n π , n ∈Z . We quantize the solutions and calculate several mass spectra for N =2 . Finally we discuss generalization for N ≧3 .

  16. Fermionic Quantization and Configuration Spaces for the Skyrme and Faddeev-Hopf Models

    NASA Astrophysics Data System (ADS)

    Auckly, Dave; Speight, Martin

    2006-04-01

    The fundamental group and rational cohomology of the configuration spaces of the Skyrme and Faddeev-Hopf models are computed. Physical space is taken to be a compact oriented 3-manifold, either with or without a marked point representing an end at infinity. For the Skyrme model, the codomain is any Lie group, while for the Faddeev-Hopf model it is S 2. It is determined when the topology of configuration space permits fermionic and isospinorial quantization of the solitons of the model within generalizations of the frameworks of Finkelstein-Rubinstein and Sorkin. Fermionic quantization of Skyrmions is possible only if the target group contains a symplectic or special unitary factor, while fermionic quantization of Hopfions is always possible. Geometric interpretations of the results are given.

  17. Solitons in a baby-Skyrme model with invariance under area-preserving diffeomorphisms

    NASA Astrophysics Data System (ADS)

    Gisiger, T.; Paranjape, M. B.

    1997-06-01

    We study the properties of soliton solutions in an analogue of the Skyrme model in 2+1 dimensions whose Lagrangian contains the Skyrme term and the mass term, but no usual kinetic term. The model admits a symmetry under area-preserving diffeomorphisms. We solve the dynamical equations of motion analytically for the case of spinning isolated baryon-type solitons. We take fully into account the induced deformation of the spinning Skyrmions and the consequent modification of its moment of inertia to give an analytical example of related numerical behavior found by Piette, Schroers, and Zakrzewski. We solve the equations of motion also for the case of an infinite, open string, and a closed annular string. In each case, the solitons are of finite extent, so called ``compactons,'' being exactly the vacuum outside a compact region. We end with indications on the scattering of baby Skyrmions, as well as some considerations as the properties of solitons on a curved space.

  18. Self-consistent theory of finite Fermi systems vs Skyrme-Hartree-Fock method. Spherical nuclei

    NASA Astrophysics Data System (ADS)

    Saperstein, E. E.; Tolokonnikov, S. V.

    2016-01-01

    Recent results of the Fayans energy density functional (EDF) for spherical nuclei are reviewed. A comparison is made with predictions of several Skyrme EDFs. The charge radii and characteristics of the first 2+ excitations in semi-magic nuclei are briefly discussed. The single-particle spectra of doubly magic nuclei are considered in more detail. The phonon-particle coupling effects are analyzed including the tadpole term.

  19. E2/M1 ratio of the N to Delta transition in a modified Skyrme model

    NASA Astrophysics Data System (ADS)

    Back, Anthony Randolph

    1997-08-01

    I use a chiral effective Lagrangian to find the E2/M1 ratio. This ratio is a measure of the deformation of the nucleon. The Lagrangian is a modified Skyrme model (1). Its construction is guided by chiral symmetry and the symmetries of QCD, which dictates the addition of the Wess-Zumino term. The current is quantized using collective coordinates (2). I find the ratio to be - .118%, which is smaller than most other models.

  20. Do Skyrme forces that fit nuclear matter work well in finite nuclei?

    NASA Astrophysics Data System (ADS)

    Stevenson, P. D.; Goddard, P. M.; Stone, J. R.; Dutra, M.

    2013-05-01

    A short list of Skyrme force parameterizations, recently found to have passed a series of constraints relating to nuclear matter properties is analyzed for their ability to reproduce data in finite nuclei. We analyse binding energies, isotope shifts, neutron skin thicknesses and fission barriers. We find that the subset of forces have no common ability to reproduce(or otherwise)properties of finite nuclei, despite passing the extensive range of nuclear matter constraints.

  1. Nuclear charge and neutron radii and nuclear matter: Trend analysis in Skyrme density-functional-theory approach

    NASA Astrophysics Data System (ADS)

    Reinhard, P.-G.; Nazarewicz, W.

    2016-05-01

    Background: Radii of charge and neutron distributions are fundamental nuclear properties. They depend on both nuclear interaction parameters related to the equation of state of infinite nuclear matter and on quantal shell effects, which are strongly impacted by the presence of nuclear surface. Purpose: In this work, by studying the correlation of charge and neutron radii, and neutron skin, with nuclear matter parameters, we assess different mechanisms that drive nuclear sizes. Method: We apply nuclear density functional theory using a family of Skyrme functionals obtained by means of optimization protocols, which do not include any radius information. By performing the Monte Carlo sampling of reasonable functionals around the optimal parametrization, we scan all correlations between nuclear matter properties and observables characterizing charge and neutron distributions of spherical closed-shell nuclei 48Ca,208Pb, and 298Fl. Results: By considering the influence of various nuclear matter properties on charge and neutron radii in a multidimensional parameter space of Skyrme functionals, we demonstrate the existence of two strong relationships: (i) between the nuclear charge radii and the saturation density of symmetric nuclear matter ρ0, and (ii) between the neutron skins and the slope of the symmetry energy L . The impact of other nuclear matter properties on nuclear radii is weak or nonexistent. For functionals optimized to experimental binding energies only, proton and neutron radii are found to be weakly correlated due to canceling trends from different nuclear matter characteristics. Conclusion: The existence of only two strong relations connecting nuclear radii with nuclear matter properties has important consequences. First, by requiring that the nuclear functional reproduces the empirical saturation point of symmetric nuclear matter practically fixes the charge (or proton) radii, and vice versa. This explains the recent results of ab initio calculations

  2. Transcription factor IIIB generates extended DNA interactions in RNA polymerase III transcription complexes on tRNA genes.

    PubMed Central

    Kassavetis, G A; Riggs, D L; Negri, R; Nguyen, L H; Geiduschek, E P

    1989-01-01

    Transcription complexes that assemble on tRNA genes in a crude Saccharomyces cerevisiae cell extract extend over the entire transcription unit and approximately 40 base pairs of contiguous 5'-flanking DNA. We show here that the interaction with 5'-flanking DNA is due to a protein that copurifies with transcription factor TFIIIB through several steps of purification and shares characteristic properties that are normally ascribed to TFIIIB: dependence on prior binding of TFIIIC and great stability once the TFIIIC-TFIIIB-DNA complex is formed. SUP4 gene (tRNATyr) DNA that was cut within the 5'-flanking sequence (either 31 or 28 base pairs upstream of the transcriptional start site) was no longer able to stably incorporate TFIIIB into a transcription complex. The TFIIIB-dependent 5'-flanking DNA protein interaction was predominantly not sequence specific. The extension of the transcription complex into this DNA segment does suggest two possible explanations for highly diverse effects of flanking-sequence substitutions on tRNA gene transcription: either (i) proteins that are capable of binding to these upstream DNA segments are also potentially capable of stimulating or interfering with the incorporation of TFIIIB into transcription complexes or (ii) 5'-flanking sequence influences the rate of assembly of TFIIIB into stable transcription complexes. Images PMID:2668737

  3. Equatorial π-stacking interactions in diruthenium (II,III) tetracarboxylate complexes containing extended π-systems

    NASA Astrophysics Data System (ADS)

    O'Rourke, Natasha F.; Ronaldson, Michael; Stanley Cameron, T.; Wang, Ruiyao; Aquino, Manuel A. S.

    2013-11-01

    The synthesis of three new valent-averaged tetracarboxylatodiruthenium (II,III) complexes, [Ru2(1-naphthylacetate)4(H2O)2](PF6)ṡ4THF, 1ṡ4THF, [Ru2(2-naphthoate)4(THF)2](PF6)ṡ3THF, 2ṡ3THF, and [Ru2(coumarin-3-carboxylate)4(MeOH)2](PF6)ṡMeOHṡH2O, 3ṡMeOHṡH2O, was accomplished using a well documented carboxylate exchange reaction. All three complexes were thoroughly characterized using infrared and UV-Vis spectroscopies, elemental analysis and X-ray diffraction. Due to the extended π-systems present, two of the complexes, 2ṡ3THF and 3ṡMeOHṡH2O, display extensive π-stacking in two dimensions, with similar interactions notably absent in 1ṡ4THF due to the perpendicular orientation of the naphthyl rings. Modest H-bonding is seen in complexes 1ṡ4THF and 3ṡMeOHṡH2O. As these types of complexes are noted secondary building units (SBU's) in the construction of metal-organic frameworks (MOF's), the significance of these interactions in stabilizing even larger, supramolecular structures, are noted.

  4. Extended Stokes Shift in Fluorescent Proteins: Chromophore–Protein Interactions in a Near-Infrared TagRFP675 Variant

    PubMed Central

    Piatkevich, Kiryl D.; Malashkevich, Vladimir N.; Morozova, Kateryna S.; Nemkovich, Nicolai A.; Almo, Steven C.; Verkhusha, Vladislav V.

    2013-01-01

    Most GFP-like fluorescent proteins exhibit small Stokes shifts (10–45 nm) due to rigidity of the chromophore environment that excludes non-fluorescent relaxation to a ground state. An unusual near-infrared derivative of the red fluorescent protein mKate, named TagRFP675, exhibits the Stokes shift, which is 30 nm extended comparing to that of the parental protein. In physiological conditions, TagRFP675 absorbs at 598 nm and emits at 675 nm that makes it the most red-shifted protein of the GFP-like protein family. In addition, its emission maximum strongly depends on the excitation wavelength. Structures of TagRFP675 revealed the common DsRed-like chromophore, which, however, interacts with the protein matrix via an extensive network of hydrogen bonds capable of large flexibility. Based on the spectroscopic, biochemical, and structural analysis we suggest that the rearrangement of the hydrogen bond interactions between the chromophore and the protein matrix is responsible for the TagRFP675 spectral properties. PMID:23677204

  5. Interactive 3D-PDF Presentations for the Simulation and Quantification of Extended Endoscopic Endonasal Surgical Approaches.

    PubMed

    Mavar-Haramija, Marija; Prats-Galino, Alberto; Méndez, Juan A Juanes; Puigdelívoll-Sánchez, Anna; de Notaris, Matteo

    2015-10-01

    A three-dimensional (3D) model of the skull base was reconstructed from the pre- and post-dissection head CT images and embedded in a Portable Document Format (PDF) file, which can be opened by freely available software and used offline. The CT images were segmented using a specific 3D software platform for biomedical data, and the resulting 3D geometrical models of anatomical structures were used for dual purpose: to simulate the extended endoscopic endonasal transsphenoidal approaches and to perform the quantitative analysis of the procedures. The analysis consisted of bone removal quantification and the calculation of quantitative parameters (surgical freedom and exposure area) of each procedure. The results are presented in three PDF documents containing JavaScript-based functions. The 3D-PDF files include reconstructions of the nasal structures (nasal septum, vomer, middle turbinates), the bony structures of the anterior skull base and maxillofacial region and partial reconstructions of the optic nerve, the hypoglossal and vidian canals and the internal carotid arteries. Alongside the anatomical model, axial, sagittal and coronal CT images are shown. Interactive 3D presentations were created to explain the surgery and the associated quantification methods step-by-step. The resulting 3D-PDF files allow the user to interact with the model through easily available software, free of charge and in an intuitive manner. The files are available for offline use on a personal computer and no previous specialized knowledge in informatics is required. The documents can be downloaded at http://hdl.handle.net/2445/55224 . PMID:26306875

  6. Extended intermolecular interactions in a serine protease-canonical inhibitor complex account for strong and highly specific inhibition.

    PubMed

    Fodor, Krisztián; Harmat, Veronika; Hetényi, Csaba; Kardos, József; Antal, József; Perczel, András; Patthy, András; Katona, Gergely; Gráf, László

    2005-07-01

    We have previously shown that a trypsin inhibitor from desert locust Schistocerca gregaria (SGTI) is a taxon-specific inhibitor that inhibits arthropod trypsins, such as crayfish trypsin, five orders of magnitude more effectively than mammalian trypsins. Thermal denaturation experiments, presented here, confirm the inhibition kinetics studies; upon addition of SGTI the melting temperatures of crayfish and bovine trypsins increased 27 degrees C and 4.5 degrees C, respectively. To explore the structural features responsible for this taxon specificity we crystallized natural crayfish trypsin in complex with chemically synthesized SGTI. This is the first X-ray structure of an arthropod trypsin and also the highest resolution (1.2A) structure of a trypsin-protein inhibitor complex reported so far. Structural data show that in addition to the primary binding loop, residues P3-P3' of SGTI, the interactions between SGTI and the crayfish enzyme are also extended over the P12-P4 and P4'-P5' regions. This is partly due to a structural change of region P10-P4 in the SGTI structure induced by binding of the inhibitor to crayfish trypsin. The comparison of SGTI-crayfish trypsin and SGTI-bovine trypsin complexes by structure-based calculations revealed a significant interaction energy surplus for the SGTI-crayfish trypsin complex distributed over the entire binding region. The new regions that account for stronger and more specific binding of SGTI to crayfish than to bovine trypsin offer new inhibitor sites to engineer in order to develop efficient and specific protease inhibitors for practical use. PMID:15922357

  7. Extended-soft-core baryon-baryon model. I. Nucleon-nucleon scattering with the ESC04 interaction

    SciTech Connect

    Rijken, Th.A.

    2006-04-15

    The NN results are presented from the extended-soft-core (ESC) interactions. They consist of local and nonlocal potentials due to (i) one-boson-exchanges (OBE), which are the members of nonets of pseudoscalar, vector, scalar, and axial mesons (ii) diffractive exchanges (iii) two-pseudoscalar exchanges (PS-PS), and (iv) meson-pair exchanges (MPE). We describe a fit to the pp and np data for 0{<=}T{sub lab}{<=}350 MeV, having a typical {chi}{sup 2}/N{sub data}=1.155. Here, we used {approx}20 quasi-free physical parameters, which are coupling constants and cutoff masses. A remarkable feature of the couplings is that we were able to require them to follow rather closely the pattern predicted by the {sup 3}P{sub 0} quark-pair-creation (QPC) model. As a result the 11 OBE couplings are rather constrained, i.e., quasi free. Also, the deuteron binding energy and the several NN scattering lengths are fitted.

  8. Intermolecular interaction and the extended wormlike chain conformation of chitin in NaOH/urea aqueous solution.

    PubMed

    Fang, Yan; Duan, Bo; Lu, Ang; Liu, Maili; Liu, Huili; Xu, Xiaojuan; Zhang, Lina

    2015-04-13

    The intra- and intermolecular interactions of chitin in NaOH/urea aqueous system were studied by a combination of NMR measurements (including (13)C NMR, (23)Na NMR, and (15)N NMR) and differential scanning calorimetry. The results revealed that the NaOH and chitin formed a hydrogen-bonded complex that was surrounded by the urea hydrates to form a sheath-like structure, leading to the good dissolution. The optimal concentration range, in which chitin was molecularly dispersed in NaOH/urea aqueous, was found to investigate the chain conformation in the dilute solution with a combination of static and dynamic light scattering. The weight-average molecular weight (Mw), radii of gyration (⟨Rg⟩z), and hydrodynamic radii (⟨Rh⟩z) values of chitin were determined, and the structure-sensitive parameter (ρ) and persistent length (Lp) were calculated to be >2.0 and ∼30 nm, respectively, suggesting an extended wormlike chain conformation. The visualized images from TEM, cryo-TEM, and AFM indicated that, chitin nanofibers were fabricated from the parallel aggregation of chitin chains in NaOH/urea system. This work would provide a theoretical guidance for constructing novel chitin-based nanomaterials via "bottom-up" method at the molecular level. PMID:25712045

  9. Dynamics of the Extended String-Like Interaction of TFIIE with the p62 Subunit of TFIIH.

    PubMed

    Okuda, Masahiko; Higo, Junichi; Komatsu, Tadashi; Konuma, Tsuyoshi; Sugase, Kenji; Nishimura, Yoshifumi

    2016-09-01

    General transcription factor II E (TFIIE) contains an acid-rich region (residues 378-393) in its α-subunit, comprising 13 acidic and two hydrophobic (Phe387 and Val390) residues. Upon binding to the p62 subunit of TFIIH, the acidic region adopts an extended string-like structure on the basic groove of the pleckstrin homology domain (PHD) of p62, and inserts Phe387 and Val390 into two shallow pockets in the groove. Here, we have examined the dynamics of this interaction by NMR and molecular dynamics (MD) simulations. Although alanine substitution of Phe387 and/or Val390 greatly reduced binding to PHD, the binding mode of the mutants was similar to that of the wild-type, as judged by the chemical-shift changes of the PHD. NMR relaxation dispersion profiles of the interaction exhibited large amplitudes for residues in the C-terminal half-string in the acidic region (Phe387, Glu388, Val390, Ala391, and Asp392), indicating a two-site binding mode: one corresponding to the final complex structure, and one to an off-pathway minor complex. To probe the off-pathway complex structure, an atomically detailed free-energy landscape of the binding mode was computed by all-atom multicanonical MD. The most thermodynamically stable cluster corresponded to the final complex structure. One of the next stable clusters was the off-pathway structure cluster, showing the reversed orientation of the C-terminal half-string on the PHD groove, as compared with the final structure. MD calculations elucidated that the C-terminal half-acidic-string forms encounter complexes mainly around the positive groove region with nearly two different orientations of the string, parallel and antiparallel to the final structure. Interestingly, the most encountered complexes exhibit a parallel-like orientation, suggesting that the string has a tendency to bind around the groove in the proper orientation with the aid of Phe387 and/or Val390 to proceed smoothly to the final complex structure. PMID:27602723

  10. BioC-compatible full-text passage detection for protein-protein interactions using extended dependency graph.

    PubMed

    Peng, Yifan; Arighi, Cecilia; Wu, Cathy H; Vijay-Shanker, K

    2016-01-01

    There has been a large growth in the number of biomedical publications that report experimental results. Many of these results concern detection of protein-protein interactions (PPI). In BioCreative V, we participated in the BioC task and developed a PPI system to detect text passages with PPIs in the full-text articles. By adopting the BioC format, the output of the system can be seamlessly added to the biocuration pipeline with little effort required for the system integration. A distinctive feature of our PPI system is that it utilizes extended dependency graph, an intermediate level of representation that attempts to abstract away syntactic variations in text. As a result, we are able to use only a limited set of rules to extract PPI pairs in the sentences, and additional rules to detect additional passages for PPI pairs. For evaluation, we used the 95 articles that were provided for the BioC annotation task. We retrieved the unique PPIs from the BioGRID database for these articles and show that our system achieves a recall of 83.5%. In order to evaluate the detection of passages with PPIs, we further annotated Abstract and Results sections of 20 documents from the dataset and show that an f-value of 80.5% was obtained. To evaluate the generalizability of the system, we also conducted experiments on AIMed, a well-known PPI corpus. We achieved an f-value of 76.1% for sentence detection and an f-value of 64.7% for unique PPI detection.Database URL: http://proteininformationresource.org/iprolink/corpora. PMID:27170286

  11. BioC-compatible full-text passage detection for protein–protein interactions using extended dependency graph

    PubMed Central

    Arighi, Cecilia; Wu, Cathy H.; Vijay-Shanker, K.

    2016-01-01

    There has been a large growth in the number of biomedical publications that report experimental results. Many of these results concern detection of protein–protein interactions (PPI). In BioCreative V, we participated in the BioC task and developed a PPI system to detect text passages with PPIs in the full-text articles. By adopting the BioC format, the output of the system can be seamlessly added to the biocuration pipeline with little effort required for the system integration. A distinctive feature of our PPI system is that it utilizes extended dependency graph, an intermediate level of representation that attempts to abstract away syntactic variations in text. As a result, we are able to use only a limited set of rules to extract PPI pairs in the sentences, and additional rules to detect additional passages for PPI pairs. For evaluation, we used the 95 articles that were provided for the BioC annotation task. We retrieved the unique PPIs from the BioGRID database for these articles and show that our system achieves a recall of 83.5%. In order to evaluate the detection of passages with PPIs, we further annotated Abstract and Results sections of 20 documents from the dataset and show that an f-value of 80.5% was obtained. To evaluate the generalizability of the system, we also conducted experiments on AIMed, a well-known PPI corpus. We achieved an f-value of 76.1% for sentence detection and an f-value of 64.7% for unique PPI detection. Database URL: http://proteininformationresource.org/iprolink/corpora PMID:27170286

  12. A through-space description of substituent effects leads to inaccurate molecular electrostatic potentials and cationπ interactions in extended aromatic systems.

    PubMed

    Cabaleiro-Lago, Enrique M; Rodríguez-Otero, Jesús

    2016-05-18

    Non-local effects are crucial in order to give an accurate description of substituent effects in extended aromatic systems. As a consequence, the predictions based on the currently accepted through-space picture can lead to large errors in the strength of cationπ interactions, especially for rings furthest from the substituent. PMID:27160488

  13. Description of elastic polarized-deuteron scattering in the optical model with Skyrme forces

    NASA Astrophysics Data System (ADS)

    Pilipenko, V. V.; Kuprikov, V. I.

    2015-07-01

    Microscopic deuteron-nucleus optical potential was constructed on the basis of the nucleon-nucleus optical potentials recently obtained by the authors from approximate calculations of the mass operator of the single-particle Green function using the Skyrme forces, which in general involve additional density- and momentum-dependent terms. Both the nucleon- and deuteron-nucleus elastic scattering processes are described in a self-consistent approach using the effective nucleon-nucleon forces, which simultaneously provide a satisfactory description of nuclear structure. The calculations performed using the Watanabe-type approximation have made it possible to obtain reasonable results for describing differential cross sections and polarization observables for the elastic deuteron scattering in a wide range of target-nucleus mass numbers at different incident deuteron energies, when using several Skyrme-force variants both from literature and proposed by the authors. Contributions to elastic deuteron-nucleus scattering cross sections coming from the effects of deuteron virtual breakup have been estimated in the continuum-discretized coupled channels approach.

  14. Solitons in a baby-Skyrme model with invariance under area-preserving diffeomorphisms

    SciTech Connect

    Gisiger, T.; Paranjape, M.B.

    1997-06-01

    We study the properties of soliton solutions in an analogue of the Skyrme model in 2+1 dimensions whose Lagrangian contains the Skyrme term and the mass term, but no usual kinetic term. The model admits a symmetry under area-preserving diffeomorphisms. We solve the dynamical equations of motion analytically for the case of spinning isolated baryon-type solitons. We take fully into account the induced deformation of the spinning Skyrmions and the consequent modification of its moment of inertia to give an analytical example of related numerical behavior found by Piette, Schroers, and Zakrzewski. We solve the equations of motion also for the case of an infinite, open string, and a closed annular string. In each case, the solitons are of finite extent, so called {open_quotes}compactons,{close_quotes} being exactly the vacuum outside a compact region. We end with indications on the scattering of baby Skyrmions, as well as some considerations as the properties of solitons on a curved space. {copyright} {ital 1997} {ital The American Physical Society}

  15. Development of an extended BIEM and its application to the analysis of earthquake dynamic rupture interacting with a medium interface

    NASA Astrophysics Data System (ADS)

    Kusakabe, T.; Kame, N.

    2013-12-01

    An extended boundary integral equation method (XBIEM) has been recently proposed for the analysis of dynamic crack growth (=dynamic earthquake rupture model) in an inhomogeneous medium consisting of homogeneous sub-regions. Originally XBIEM is applicable to non-planar geometry of cracks and medium interfaces, but it has been demonstrated only for a simple planar crack along a bimaterial interface. Here we developed a code to analyse non-planar rupture with non-planar interfaces in a mode III problem, and applied it to a dynamic rupture problem across a planar bimaterial interface to investigate the effect of medium inhomogeneity. For this purpose, we firstly derived all the displacement and displacement velocity kernels in a unified analytic discretized form, in addition to the stress kernels already derived, necessary for versatile geometry of boundaries (i.e., cracks and interfaces) and checked all the kernel components in the simulation of wave propagation across a non-planar interface cutting a homogeneous medium. Then we validated our code in a wave reflection-transmission problem across a planar bimaterial interface. Secondly, in order to realize the analysis of dynamic rupture crossing a bimaterial interface we introduced a new implicit time-stepping scheme for instantaneously interacting boundary elements on the crack and medium interface. Such interactions only appear in the crack's crossing the interface. Otherwise we can use the explicit scheme as employed for BIEM in a homogeneous medium. We validated our numerical code for the crack growth in a homogeneous medium cut with a planar interface and found that our new scheme worked well. Finally, we tackled dynamic rupture propagation on a planar fault embedded normal to the planar interface of a bimaterial. Spontaneous rupture was allowed not only on the planar main fault but also on the interfacial fault and it is controlled by different slip-weakening laws on each of them: each peak strength is

  16. Reconciling Experiment and Theory in the Use of Aryl-Extended Calix[4]pyrrole Receptors for the Experimental Quantification of Chloride–π Interactions in Solution

    PubMed Central

    Bauzá, Antonio; Quiñonero, David; Frontera, Antonio; Ballester, Pablo

    2015-01-01

    In this manuscript we consider from a theoretical point of view the recently reported experimental quantification of anion–π interactions (the attractive force between electron deficient aromatic rings and anions) in solution using aryl extended calix[4]pyrrole receptors as model systems. Experimentally, two series of calix[4]pyrrole receptors functionalized, respectively, with two and four aryl rings at the meso positions, were used to assess the strength of chloride–π interactions in acetonitrile solution. As a result of these studies the contribution of each individual chloride–π interaction was quantified to be very small (<1 kcal/mol). This result is in contrast with the values derived from most theoretical calculations. Herein we report a theoretical study using high-level density functional theory (DFT) calculations that provides a plausible explanation for the observed disagreement between theory and experiment. The study reveals the existence of molecular interactions between solvent molecules and the aromatic walls of the receptors that strongly modulate the chloride–π interaction. In addition, the obtained theoretical results also suggest that the chloride-calix[4]pyrrole complex used as reference to dissect experimentally the contribution of the chloride–π interactions to the total binding energy for both the two and four-wall aryl-extended calix[4]pyrrole model systems is probably not ideal. PMID:25913375

  17. Connecting with The Biggest Loser: an extended model of parasocial interaction and identification in health-related reality TV shows.

    PubMed

    Tian, Yan; Yoo, Jina H

    2015-01-01

    This study investigates audience responses to health-related reality TV shows in the setting of The Biggest Loser. It conceptualizes a model for audience members' parasocial interaction and identification with cast members and explores antecedents and outcomes of parasocial interaction and identification. Data analysis suggests the following direct relationships: (1) audience members' exposure to the show is positively associated with parasocial interaction, which in turn is positively associated with identification, (2) parasocial interaction is positively associated with exercise self-efficacy, whereas identification is negatively associated with exercise self-efficacy, and (3) exercise self-efficacy is positively associated with exercise behavior. Indirect effects of parasocial interaction and identification on exercise self-efficacy and exercise behavior are also significant. We discuss the theoretical and practical implications of these findings. PMID:24579692

  18. Pion-nucleon scattering in the Skyrme model and the P-wave Born amplitudes

    NASA Astrophysics Data System (ADS)

    Hayashi, A.; Saito, S.; Uehara, M.

    1991-03-01

    We treat fluctuating pion fields around a rotating Skyrmion by means of Dirac's quantization method. The rotational collective motion of the Skyrmion is described by collective coordinates, and conventional gauge-fixing conditions are imposed. Taking into account all the relevant terms at the tree level appearing in the Hamiltonian, we show that pion-nucleon scattering amplitudes exhibit the P-wave Born amplitudes attributed to the Yukawa coupling of order √Nc , which is consistent with the prediction of chiral symmetry such as the Adler-Weisberger relation. This resolves the difficulty that the Skyrme model predicts a wrong Nc dependence for the coupling of order N-3/2c.

  19. Multidimensional Skyrme-density-functional study of the spontaneous fission of 238U

    DOE PAGESBeta

    Sadhukhan, J.; Mazurek, K.; Dobaczewski, J.; Nazarewicz, W.; Sheikh, J. A.; Baran, A.

    2015-01-01

    We determined the spontaneous fission lifetime of 238U by a minimization of the action integral in a three-dimensional space of collective variables. Apart from the mass-distribution multipole moments Q20 (elongation) and Q30 (left–right asymmetry), we also considered the pairing-fluctuation parameter λ2 as a collective coordinate. The collective potential was obtained self-consistently using the Skyrme energy density functional SkM*. The inertia tensor was obtained within the nonperturbative cranking approximation to the adiabatic time-dependent Hartree–Fock–Bogoliubov approach. As a result, the pairing-fluctuation parameter λ2 allowed us to control the pairing gap along the fission path, which significantly changed the spontaneous fission lifetime.

  20. Multidimensional Skyrme-density-functional study of the spontaneous fission of 238U

    SciTech Connect

    Sadhukhan, J.; Mazurek, K.; Dobaczewski, J.; Nazarewicz, W.; Sheikh, J. A.; Baran, A.

    2015-01-01

    We determined the spontaneous fission lifetime of 238U by a minimization of the action integral in a three-dimensional space of collective variables. Apart from the mass-distribution multipole moments Q20 (elongation) and Q30 (left–right asymmetry), we also considered the pairing-fluctuation parameter λ2 as a collective coordinate. The collective potential was obtained self-consistently using the Skyrme energy density functional SkM*. The inertia tensor was obtained within the nonperturbative cranking approximation to the adiabatic time-dependent Hartree–Fock–Bogoliubov approach. As a result, the pairing-fluctuation parameter λ2 allowed us to control the pairing gap along the fission path, which significantly changed the spontaneous fission lifetime.

  1. Fractional vortex molecules and vortex polygons in a baby Skyrme model

    NASA Astrophysics Data System (ADS)

    Kobayashi, Michikazu; Nitta, Muneto

    2013-06-01

    We construct a molecule of fractional vortices with fractional topological lump charges as a baby Skyrmion with the unit topological lump charge in the antiferromagnetic (or XY) baby Skyrme model, that is, an O(3) sigma model with a four-derivative term and an antiferromagnetic or XY-type potential term quadratic in fields. We further construct configurations with topological lump charges Q≤7 and find that bound states of vortex molecules constitute regular polygons with 2Q vertices as vortices, where the rotational symmetry SO(2) in real space is spontaneously broken into a discrete subgroup ZQ. We also find metastable and arrayed bound states of fractional vortices for Q=5, 6. On the other hand, we find for Q=7 that the regular polygon is metastable and the arrayed bound state is stable. We calculate binding energies of all configurations.

  2. Skyrme random-phase-approximation description of lowest Kπ=2γ+ states in axially deformed nuclei

    NASA Astrophysics Data System (ADS)

    Nesterenko, V. O.; Kartavenko, V. G.; Kleinig, W.; Kvasil, J.; Repko, A.; Jolos, R. V.; Reinhard, P.-G.

    2016-03-01

    The lowest quadrupole γ -vibrational Kπ=2+ states in axially deformed rare-earth (Nd, Sm, Gd, Dy, Er, Yb, Hf, W) and actinide (U) nuclei are systematically investigated within the separable random-phase-approximation (SRPA) based on the Skyrme functional. The energies Eγ and reduced transition probabilities B (E 2 ) of 2γ+ states are calculated with the Skyrme forces SV-bas and SkM*. The energies of two-quasiparticle configurations forming the SRPA basis are corrected by using the pairing blocking effect. This results in a systematic downshift of Eγ by 0.3-0.5 MeV and thus in a better agreement with the experiment, especially in Sm, Gd, Dy, Hf, and W regions. For other isotopic chains, a noticeable overestimation of Eγ and too weak collectivity of 2γ+ states still persist. It is shown that domains of nuclei with low and high 2γ+ collectivity are related to the structure of the lowest two-quasiparticle states and conservation of the Nilsson selection rules. The description of 2γ+ states with SV-bas and SkM* is similar in light rare-earth nuclei but deviates in heavier nuclei. However SV-bas much better reproduces the quadrupole deformation and energy of the isoscalar giant quadrupole resonance. The accuracy of SRPA is justified by comparison with exact RPA. The calculations suggest that a further development of the self-consistent calculation schemes is needed for a systematic satisfactory description of the 2γ+ states.

  3. Space science education by Mathematica demonstrations: interactive conceptual design for foldable and extendable structures for space applications

    NASA Astrophysics Data System (ADS)

    Kabai, S.; Berczi, Sz.

    2008-09-01

    By the interactive Mathematica Demonstrations of the Wolfram Research instrumentation [1], various mechanics and space motion operation simulations of any spacecraft was studied. The authors created great number of Mathematica demonstrations which are available from the Wolfram Demonstration site.

  4. Root–root interactions: extending our perspective to be more inclusive of the range of theories in ecology and agriculture using in-vivo analyses

    PubMed Central

    Faget, Marc; Nagel, Kerstin A.; Walter, Achim; Herrera, Juan M.; Jahnke, Siegfried; Schurr, Ulrich; Temperton, Vicky M.

    2013-01-01

    Background There is a large body of literature on competitive interactions among plants, but many studies have only focused on above-ground interactions and little is known about root–root dynamics between interacting plants. The perspective on possible mechanisms that explain the outcome of root–root interactions has recently been extended to include non-resource-driven mechanisms (as well as resource-driven mechanisms) of root competition and positive interactions such as facilitation. These approaches have often suffered from being static, partly due to the lack of appropriate methodologies for in-situ non-destructive root characterization. Scope Recent studies show that interactive effects of plant neighbourhood interactions follow non-linear and non-additive paths that are hard to explain. Common outcomes such as accumulation of roots mainly in the topsoil cannot be explained solely by competition theory but require a more inclusive theoretical, as well as an improved methodological framework. This will include the question of whether we can apply the same conceptual framework to crop versus natural species. Conclusions The development of non-invasive methods to dynamically study root–root interactions in vivo will provide the necessary tools to study a more inclusive conceptual framework for root–root interactions. By following the dynamics of root–root interactions through time in a whole range of scenarios and systems, using a wide variety of non-invasive methods, (such as fluorescent protein which now allows us to separately identify the roots of several individuals within soil), we will be much better equipped to answer some of the key questions in root physiology, ecology and agronomy. PMID:23378521

  5. In Silico, Experimental, Mechanistic Model for Extended-Release Felodipine Disposition Exhibiting Complex Absorption and a Highly Variable Food Interaction

    PubMed Central

    Kim, Sean H. J.; Jackson, Andre J.; Hunt, C. Anthony

    2014-01-01

    The objective of this study was to develop and explore new, in silico experimental methods for deciphering complex, highly variable absorption and food interaction pharmacokinetics observed for a modified-release drug product. Toward that aim, we constructed an executable software analog of study participants to whom product was administered orally. The analog is an object- and agent-oriented, discrete event system, which consists of grid spaces and event mechanisms that map abstractly to different physiological features and processes. Analog mechanisms were made sufficiently complicated to achieve prespecified similarity criteria. An equation-based gastrointestinal transit model with nonlinear mixed effects analysis provided a standard for comparison. Subject-specific parameterizations enabled each executed analog’s plasma profile to mimic features of the corresponding six individual pairs of subject plasma profiles. All achieved prespecified, quantitative similarity criteria, and outperformed the gastrointestinal transit model estimations. We observed important subject-specific interactions within the simulation and mechanistic differences between the two models. We hypothesize that mechanisms, events, and their causes occurring during simulations had counterparts within the food interaction study: they are working, evolvable, concrete theories of dynamic interactions occurring within individual subjects. The approach presented provides new, experimental strategies for unraveling the mechanistic basis of complex pharmacological interactions and observed variability. PMID:25268237

  6. Non-covalent interactions in extended systems described by the Effective Fragment Potential method: Theory and application to nucleobase oligomers

    PubMed Central

    Ghosh, Debashree; Kosenkov, Dmytro; Vanovschi, Vitalii; Williams, Christopher F.; Herbert, John M.; Gordon, Mark S.; Schmidt, Michael W.; Slipchenko, Lyudmila V.; Krylov, Anna I.

    2010-01-01

    The implementation of the Effective Fragment Potential (EFP) method within the Q-Chem electronic structure package is presented. The EFP method is used to study non-covalent π – π and hydrogen-bonding interactions in DNA strands. Since EFP is a computationally inexpensive alternative to high-level ab initio calculations, it is possible to go beyond the dimers of nucleic acid bases and to investigate the asymptotic behavior of different components of the total interaction energy. The calculations demonstrated that the dispersion energy is a leading component in π-stacked oligomers of all sizes. Exchange-repulsion energy also plays an important role. The contribution of polarization is small in these systems, whereas the magnitude of electrostatics varies. Pairwise fragment interactions (i.e., the sum of dimer binding energies) were found to be a good approximation for the oligomer energy. PMID:21067134

  7. Estimating spatial accessibility to facilities on the regional scale: an extended commuting-based interaction potential model

    PubMed Central

    2011-01-01

    Background There is growing interest in the study of the relationships between individual health-related behaviours (e.g. food intake and physical activity) and measurements of spatial accessibility to the associated facilities (e.g. food outlets and sport facilities). The aim of this study is to propose measurements of spatial accessibility to facilities on the regional scale, using aggregated data. We first used a potential accessibility model that partly makes it possible to overcome the limitations of the most frequently used indices such as the count of opportunities within a given neighbourhood. We then propose an extended model in order to take into account both home and work-based accessibility for a commuting population. Results Potential accessibility estimation provides a very different picture of the accessibility levels experienced by the population than the more classical "number of opportunities per census tract" index. The extended model for commuters increases the overall accessibility levels but this increase differs according to the urbanisation level. Strongest increases are observed in some rural municipalities with initial low accessibility levels. Distance to major urban poles seems to play an essential role. Conclusions Accessibility is a multi-dimensional concept that should integrate some aspects of travel behaviour. Our work supports the evidence that the choice of appropriate accessibility indices including both residential and non-residential environmental features is necessary. Such models have potential implications for providing relevant information to policy-makers in the field of public health. PMID:21219597

  8. Efficient proton acceleration and focusing by an ultraintense laser interacting with a parabolic double concave target with an extended rear

    SciTech Connect

    Bake, Muhammad Ali; Xie, Bai-Song; Aimidula, Aimierding; Wang, Hong-Yu

    2013-07-15

    A new scheme for acceleration and focusing of protons via an improved parabolic double concave target irradiated by an ultraintense laser pulse is proposed. When an intense laser pulse illuminates a concave target, the hot electrons are concentrated on the focal region of the rear cavity and they form a strong space-charge-separation field, which accelerates the protons. For a simple concave target, the proton energy spectrum becomes very broad outside the rear cavity because of transverse divergence of the electromagnetic fields. However, particle-in-cell simulations show that, when the concave target has an extended rear, the hot electrons along the wall surface induce a transverse focusing sheath field, resulting in a clear enhancement of proton focusing, which makes the lower proton energy spread, while, leads to a little reduction of the proton bunch peak energy.

  9. Efficient proton acceleration and focusing by an ultraintense laser interacting with a parabolic double concave target with an extended rear

    NASA Astrophysics Data System (ADS)

    Bake, Muhammad Ali; Xie, Bai-Song; Aimidula, Aimierding; Wang, Hong-Yu

    2013-07-01

    A new scheme for acceleration and focusing of protons via an improved parabolic double concave target irradiated by an ultraintense laser pulse is proposed. When an intense laser pulse illuminates a concave target, the hot electrons are concentrated on the focal region of the rear cavity and they form a strong space-charge-separation field, which accelerates the protons. For a simple concave target, the proton energy spectrum becomes very broad outside the rear cavity because of transverse divergence of the electromagnetic fields. However, particle-in-cell simulations show that, when the concave target has an extended rear, the hot electrons along the wall surface induce a transverse focusing sheath field, resulting in a clear enhancement of proton focusing, which makes the lower proton energy spread, while, leads to a little reduction of the proton bunch peak energy.

  10. Uncertainty quantification of effective nuclear interactions

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    We give a brief review on the development of phenomenological NN interactions and the corresponding quantification of statistical uncertainties. We look into the uncertainty of effective interactions broadly used in mean field calculations through the Skyrme parameters and effective field theory counterterms by estimating both statistical and systematic uncertainties stemming from the NN interaction. We also comment on the role played by different fitting strategies on the light of recent developments.

  11. Diverse antimicrobial interactions of halophilic archaea and bacteria extend over geographical distances and cross the domain barrier

    PubMed Central

    Atanasova, Nina S; Pietilä, Maija K; Oksanen, Hanna M

    2013-01-01

    The significance of antimicrobial substances, halocins, produced by halophilic archaea and bacteria thriving in hypersaline environments is relatively unknown. It is suggested that their production might increase species diversity and give transient competitive advances to the producer strain. Halocin production is considered to be common among halophilic archaea, but there is a lack of information about halocins produced by bacteria in highly saline environments. We studied the antimicrobial activity of 68 halophilic archaea and 22 bacteria isolated from numerous geographically distant hypersaline environments. Altogether 144 antimicrobial interactions were found between the strains and aside haloarchaea, halophilic bacteria from various genera were identified as halocin producers. Close to 80% of the interactions were detected between microorganisms from different genera and in few cases, even across the domain boundary. Several of the strains produced halocins with a wide inhibitory spectrum as has been observed before. Most of the antimicrobial interactions were found between strains from distant sampling sites indicating that hypersaline environments around the world have similar microorganisms with the potential to produce wide activity range antimicrobials. PMID:23929527

  12. Detection of Favorable Oral Cephalosporin-Clavulanate Interactions by In Vitro Disk Approximation Susceptibility Testing of Extended-Spectrum-Beta-Lactamase-Producing Members of the Enterobacteriaceae

    PubMed Central

    Campbell, Jennifer D.; Lewis, James S.; McElmeel, M. Leticia; Fulcher, Letitia C.

    2012-01-01

    Extended-spectrum-beta-lactamase (ESBL)-producing members of the Enterobacteriaceae are often resistant to multiple drug classes, making therapy of urinary infections with oral antibiotics difficult. Previously it was shown that amoxicillin-clavulanate can provide clavulanate inhibition of ESBLs and protect an oral cephalosporin present in combination when tested by broth microdilution. This study has shown that disk approximation testing could detect favorable cephalosporin-clavulanate interactions among a group of 101 previously characterized members of the Enterobacteriaceae with CTX-M, SHV, or TEM ESBLs. PMID:22170910

  13. Cocrystal Structures of Primed Side-Extending α-Ketoamide Inhibitors Reveal Novel Calpain-Inhibitor Aromatic Interactions

    SciTech Connect

    Qian,J.; Cuerrier, D.; Davies, P.; Li, Z.; Powers, J.; Campbell, R.

    2008-01-01

    Calpains are intracellular cysteine proteases that catalyze the cleavage of target proteins in response to Ca2+ signaling. When Ca2+ homeostasis is disrupted, calpain overactivation causes unregulated proteolysis, which can contribute to diseases such as postischemic injury and cataract formation. Potent calpain inhibitors exist, but of these many cross-react with other cysteine proteases and will need modification to specifically target calpain. Here, we present crystal structures of rat calpain 1 protease core ({mu}I-II) bound to two a-ketoamide-based calpain inhibitors containing adenyl and piperazyl primed-side extensions. An unexpected aromatic-stacking interaction is observed between the primed-side adenine moiety and the Trp298 side chain. This interaction increased the potency of the inhibitor toward {mu}I-II and heterodimeric m-calpain. Moreover, stacking orients the adenine such that it can be used as a scaffold for designing novel primed-side address regions, which could be incorporated into future inhibitors to enhance their calpain specificity.

  14. Competing magnetic interactions in the extended Kagome system YBaCo{sub 4}O{sub 7}

    SciTech Connect

    Chapon, L. C.; Radaelli, P. G.; Zheng, H.; Mitchell, J. F.

    2006-11-01

    YBaCo{sub 4}O{sub 7} belongs to a new class of geometrically frustrated magnets like the pyrochlores, in which Co spins occupy corners of tetrahedra. The structure can be viewed as an alternating stacking of Kagome and triangular layers. Exactly half of the triangular units of the Kagome plane are capped by Co ions to form columns running perpendicular to the Kagome sheets. Neutron powder diffraction reveals a broad temperature range of diffuse magnetic scattering, followed by long-range magnetic ordering below 110 K. A unique low-temperature magnetic structure simultaneously satisfies an S=0 arrangement in the uncapped triangular units and antiferromagnetic coupling along the columns. A spin reorientation above 30 K tracks the relative strengths of the in-plane and out-of-plane interactions.

  15. Extending Parent–Child Interaction Therapy for Early Childhood Internalizing Problems: New Advances for an Overlooked Population

    PubMed Central

    Puliafico, Anthony C.; Kurtz, Steven M. S.; Pincus, Donna B.; Comer, Jonathan S.

    2014-01-01

    Although efficacious psychological treatments for internalizing disorders are now well established for school-aged children, until recently there have regrettably been limited empirical efforts to clarify indicated psychological intervention methods for the treatment of mood and anxiety disorders presenting in early childhood. Young children lack many of the developmental capacities required to effectively participate in established treatments for mood and anxiety problems presenting in older children, making simple downward extensions of these treatments for the management of preschool internalizing problems misguided. In recent years, a number of research groups have successfully adapted and modified parent–child interaction therapy (PCIT), originally developed to treat externalizing problems in young children, to treat various early internalizing problems with a set of neighboring protocols. As in traditional PCIT, these extensions target child symptoms by directly reshaping parent–child interaction patterns associated with the maintenance of symptoms. The present review outlines this emerging set of novel PCIT adaptations and modifications for mood and anxiety problems in young children and reviews preliminary evidence supporting their use. Specifically, we cover (a) PCIT for early separation anxiety disorder; (b) the PCIT-CALM (Coaching Approach behavior and Leading by Modeling) Program for the full range of early anxiety disorders; (c) the group Turtle Program for behavioral inhibition; and (d) the PCIT-ED (Emotional Development) Program for preschool depression. In addition, emerging PCIT-related protocols in need of empirical attention—such as the PCIT-SM (selective mutism) Program for young children with SM—are also considered. Implications of these protocols are discussed with regard to their unique potential to address the clinical needs of young children with internalizing problems. Obstacles to broad dissemination are addressed, and we consider

  16. Search for the Skyrme-Hartree-Fock solutions for chiral rotation in N=75 isotones

    SciTech Connect

    Olbratowski, P.; Dobaczewski, J.; Dudek, J.

    2006-05-15

    A search for self-consistent solutions for the chiral rotational bands in the N=75 isotones {sup 130}Cs, {sup 132}La, {sup 134}Pr, and {sup 136}Pm is performed within the Skyrme-Hartree-Fock cranking approach using SKM* and SLy4 parametrizations. The dependence of the solutions on the time-odd contributions in the energy functional is studied. From among the four isotones considered, self-consistent chiral solutions are obtained only in {sup 132}La. The microscopic calculations are compared with the {sup 132}La experimental data and with results of a classical model that contains all the mechanisms underlying the chirality of the collective rotational motion. Strong similarities between the Hartree-Fock and classical model results are found. The suggestion formulated earlier by the authors that the chiral rotation cannot exist below a certain critical frequency is further illustrated and discussed, together with the microscopic origin of a transition from planar to chiral rotation in nuclei. We also formulate the separability rule by which the tilted-axis-cranking solutions can be inferred from three independent principal-axis-cranking solutions corresponding to three different axes of rotation.

  17. A study to modify, extend, and verify, an existing model of interactive-constructivist school science teaching

    NASA Astrophysics Data System (ADS)

    Numedahl, Paul Joseph

    The purpose of this study was to gain an understanding of the effects an interactive-constructive teaching and learning approach, the use of children's literature in science teaching and parental involvement in elementary school science had on student achievement in and attitudes toward science. The study was done in the context of Science PALS, a professional development program for inservice teachers. An existing model for interactive-constructive elementary science was modified to include five model variables; student achievement, student attitudes, teacher perceptions, teacher performance, and student perceptions. Data were collected from a sample of 12 teachers and 260 third and fourth grade students. Data analysis included two components, (1) the examination of relationships between teacher performance, teacher perceptions, student achievement and attitudes, and (2) the verification of a model using path analysis. Results showed a significant correlation between teacher perceptions and student attitude. However, only one model path was significant; thus, the model could not be verified. Further examination of the significant model path was completed. Study findings included: (1) Constructivist notions of teaching and learning may cause changes in the traditional role relationship between teachers and students leading to negative student attitudes. (2) Children who perceive parental interest toward science education are likely to have a positive attitude toward science learning, increased self-confidence in science and possess accurate ideas concerning the nature of science. (3) Students who perceive science instruction as relevant are likely to possess a positive attitude toward science learning, increased self-confidence in science, and possess accurate ideas concerning the nature of science. (4) Students who perceive their classroom as aligning with constructivist principles are likely to possess a positive attitude toward science, an increased self

  18. Structure of a novel dodecaheme cytochrome c from Geobacter sulfurreducens reveals an extended 12 nm protein with interacting hemes.

    SciTech Connect

    Pokkuluri, P. R.; Londer, Y. Y.; Duke, N. E. C.; Pessanha, M.; Yang, X.; Orshonsky, V.; Orshonsky, L.; Erickson, J.; Zagyansky, Y.; Salgueiro, C. A.; Schiffer, M.

    2011-04-01

    Multiheme cytochromes c are important in electron transfer pathways in reduction of both soluble and insoluble Fe(III) by Geobacter sulfurreducens. We determined the crystal structure at 3.2 {angstrom} resolution of the first dodecaheme cytochrome c (GSU1996) along with its N-terminal and C-terminal hexaheme fragments at 2.6 and 2.15 {angstrom} resolution, respectively. The macroscopic reduction potentials of the full-length protein and its fragments were measured. The sequence of GSU1996 can be divided into four c{sub 7}-type domains (A, B, C and D) with homology to triheme cytochromes c{sub 7}. In cytochromes c{sub 7} all three hemes are bis-His coordinated, whereas in c{sub 7}-type domains the last heme is His-Met coordinated. The full-length GSU1996 has a 12 nm long crescent shaped structure with the 12 hemes arranged along a polypeptide to form a 'nanowire' of hemes; it has a modular structure. Surprisingly, while the C-terminal half of the protein consists of two separate c{sub 7}-type domains (C and D) connected by a small linker, the N-terminal half of the protein has two c{sub 7}-type domains (A and B) that form one structural unit. This is also observed in the AB fragment. There is an unexpected interaction between the hemes at the interface of domains A and B, which form a heme-pair with nearly parallel stacking of their porphyrin rings. The hemes adjacent to each other throughout the protein are within van der Waals distance which enables efficient electron exchange between them. For the first time, the structural details of c{sub 7}-type domains from one multiheme protein were compared.

  19. Modified Iterative Extended Hueckel. 2: Application to the interaction of Na(+), Na(+)(aq.), Mg(+)-2(aq.) with adenine and thymine

    NASA Technical Reports Server (NTRS)

    Aronowitz, S.; Macelroy, R.; Chang, S.

    1980-01-01

    Modified Iterative Extended Hueckel, which includes explicit effective internuclear and electronic interactions, is applied to the study of the energetics of Na(+),Mg(+), Na(+) (aqueous), and Mg(+2) (aqueous) ions approaching various possible binding sites on adenine and thymine. Results for the adenine + ion and thymine + ion are in good qualitative agreement with ab initio work on analogous systems. Energy differences between competing sites are in excellent agreement. Hydration appears to be a critical factor in determining favorable binding sites. That the adenine Nl and N3 sites cannot displace a water molecule from the hydrated cation indicates that they are not favorable binding sites in aqueous media. Of those sites investigated, 04 was the most favorable binding site on the thymine for the bare Na(+). However, the 02 site was the most favorable binding site for either hydrated cation.

  20. Solution of the Skyrme HF + BCS equation on a 3D mesh

    NASA Astrophysics Data System (ADS)

    Bonche, P.; Flocard, H.; Heenen, P. H.

    2005-09-01

    Over the years, the ev8 code has been a very useful tool for the study of nuclear mean-field theory. Its main characteristic is that it solves the Hartree-Fock plus BCS equations for Skyrme type functionals via a discretization of the individual wave-functions on a three-dimensional Cartesian mesh. This allows maximal flexibility in the determination of the nuclear shape by the variational process. For instance, the same mesh can be used to describe the oblate deformed, spherical, prolate deformed, superdeformed and fission configurations of a given nucleus. The quadrupole constraining operator yielding the deformation energy curve covering all these configurations is included in ev8. This version of the code is restricted to even-even nuclei. Program summaryTitle of program:ev8 Catalogue identifier:ADWA Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADWA Licensing provisions: none Computers on which the program has been tested: HP-RX4640, Compaq-Digital Alpha GS140, has run on several other platforms Computer for which the program is designed and others on which is has been tested:Unix, Linux Operating systems or monitors under which the program has been tested:FORTRAN-90 Programming language used:depends on problem; example given requires 60 MB Memory required to execute with typical data:yes No. of lines in distributed program, including test data, etc.:11 524 No. of bytes in distributed program, including test data, etc.:89 949 Distribution format:tar.gzip file Nature of the physical problem:By means of the Hartree-Fock plus BCS method using Skyrme type functionals, ev8 allows a study of the evolution of the binding energy of even-even nuclei for various shapes determined by the most general quadrupole constraint. Solution method:The program expands the single-particle wave-functions on a 3D Cartesian mesh. The nonlinear mean-field equations are solved by the

  1. Effects of extending the computational model on DNA-protein T-shaped interactions: the case of adenine-histidine dimers.

    PubMed

    Rutledge, Lesley R; Navarro-Whyte, Lex; Peterson, Terri L; Wetmore, Stacey D

    2011-11-17

    The MP2/6-31G*(0.25) π-π or π(+)-π T-shaped (edge-to-face) interactions between neutral or protonated histidine and adenine were considered using computational models of varying size to determine the effects of the protein and DNA backbones on the preferred dimer structure and binding strength. The overall consequences of the backbones are reasonably subtle for the neutral adenine-histidine T-shaped dimers. Furthermore, the minor changes in the binding strengths of these dimers upon model extension arise from additional (attractive) backbone-π (bb-π) contacts and changes in the preferred π-π orientations, which is verified by the quantum theory of atoms in molecules (QTAIM). Since the binding strength of the extended dimer equals the sum of the individual backbone-π and π-π contributions, the π-π component is not appreciably affected by polarization of the ring upon inclusion of the biological backbone. In contrast, the larger effect of the backbone on the protonated histidine dimers cannot simply be predicted as the sum of changes in the π-π and bb-π components regardless of the dimer type or model. This suggests, and QTAIM qualitatively supports, that the magnitude of the π(+)-π contribution changes, which is likely due to alterations in the electrostatic landscape of the monomer rings upon inclusion of the biological backbone that largely affect T-shaped dimers. These findings differ from those previously reported for (neutral) π-π stacked and (metallic) cation-π interactions, which highlights the distinct properties of each (π-π, π(+)-π, and cation-π) classification of noncovalent interaction. Furthermore, these results emphasize the importance of considering backbone-π interactions when analyzing contacts that appear in experimental crystal structures and cautions the use of truncated models when evaluating the magnitude of the π(+)-π contribution present in large biological complexes. PMID:21648440

  2. Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. XII. Stiffness and stability of neutron-star matter

    SciTech Connect

    Goriely, S.; Chamel, N.; Pearson, J. M.

    2010-09-15

    We construct three new Hartree-Fock-Bogoliubov (HFB) mass models, labeled HFB-19, HFB-20, and HFB-21, with unconventional Skyrme forces containing t{sub 4} and t{sub 5} terms, i.e., density-dependent generalizations of the usual t{sub 1} and t{sub 2} terms, respectively. The new forces underlying these models are fitted respectively to three different realistic equations of state of neutron matter for which the density dependence of the symmetry energy ranges from the very soft to the very stiff, reflecting thereby our present lack of complete knowledge of the high-density behavior of nuclear matter. All unphysical instabilities of nuclear matter, including the transition to a polarized state in neutron-star matter, are eliminated with the new forces. At the same time the new models fit essentially all the available mass data with rms deviations of 0.58 MeV and give the same high-quality fits to measured charge radii that we obtained in earlier models with conventional Skyrme forces. Being constrained by neutron matter, these new mass models, which all give similar extrapolations out to the neutron drip line, are highly appropriate for studies of the r process and the outer crust of neutron stars. Moreover, the underlying forces, labeled BSk19, BSk20 and BSk21, respectively, are well adapted to the study of the inner crust and core of neutron stars. The new family of Skyrme forces thus opens the way to a unified description of all regions of neutron stars.

  3. Properties of nuclei in the nobelium region studied within the covariant, Skyrme, and Gogny energy density functionals

    SciTech Connect

    Dobaczewski, J.; Afanasjev, A. V.; Bender, M.; Shi, Yue

    2015-07-29

    In this study, we calculate properties of the ground and excited states of nuclei in the nobelium region for proton and neutron numbers of 92 ≤ Z ≤ 104 and 144 ≤ N ≤ 156, respectively. We use three different energy-density-functional (EDF) approaches, based on covariant, Skyrme, and Gogny functionals, each with two different parameter sets. A comparative analysis of the results obtained for quasiparticle spectra, odd–even and two-particle mass staggering, and moments of inertia allows us to identify single-particle and shell effects that are characteristic to these different models and to illustrate possible systematic uncertainties related to using the EDF modelling.

  4. Extended consecutive modal pushover procedure for estimating seismic responses of one-way asymmetric plan tall buildings considering soil-structure interaction

    NASA Astrophysics Data System (ADS)

    Tehrani, Mohammad Hadikhan; Khoshnoudian, Faramarz

    2014-09-01

    Performance based design becomes an effective method for estimating seismic demands of buildings. In asymmetric plan tall building the effects of higher modes and torsion are crucial. The consecutive modal pushover (CMP) procedure is one of the procedures that consider these effects. Also in previous studies the influence of soil-structure interaction (SSI) in pushover analysis is ignored. In this paper the CMP procedure is modified for one-way asymmetric plan mid and high-rise buildings considering SSI. The extended CMP (ECMP) procedure is proposed in order to overcome some limitations of the CMP procedure. In this regard, 10, 15 and 20 story buildings with asymmetric plan are studied considering SSI assuming three different soil conditions. Using nonlinear response history analysis under a set of bidirectional ground motion; the exact responses of these buildings are calculated. Then the ECMP procedure is evaluated by comparing the results of this procedure with nonlinear time history results as an exact solution as well as the modal pushover analysis procedure and FEMA 356 load patterns. The results demonstrate the accuracy of the ECMP procedure.

  5. Effective quadrupole-quadrupole interaction from density functional theory

    NASA Astrophysics Data System (ADS)

    Alhassid, Y.; Bertsch, G. F.; Fang, L.; Sabbey, B.

    2006-09-01

    The density functional theory of nuclear structure provides a many-particle wave function that is useful for static properties, but an extension of the theory is necessary to describe correlation effects or other dynamic properties. We propose a procedure to extend the theory by mapping the properties of a self-consistent mean-field theory onto an effective shell-model Hamiltonian with quadrupole-quadrupole interaction. In this initial study, we consider the sd-shell nuclei Ne20, Mg24, Si28, and Ar36. The method is first tested with the USD shell-model Hamiltonian, using its mean-field approximation to construct an effective Hamiltonian and partially recover correlation effects. We find that more than half of the correlation energy is due to the quadrupole interaction. We then follow a similar procedure but using the SLy4 Skyrme energy functional as our starting point and truncating the space to the spherical sd shell. The constructed shell-model Hamiltonian is found to satisfy minimal consistency requirements to reproduce the properties of the mean-field solution. The quadrupolar correlation energies computed with the mapped Hamiltonian are reasonable compared with those computed by other methods. The method also provides a well-defined renormalization of the quadrupole operator in the shell-model space, the “effective charge” of the phenomenological shell model.

  6. Properties of nuclei in the nobelium region studied within the covariant, Skyrme, and Gogny energy density functionals

    DOE PAGESBeta

    Dobaczewski, J.; Afanasjev, A. V.; Bender, M.; Robledo, L. M.; Shi, Yue

    2015-07-29

    In this study, we calculate properties of the ground and excited states of nuclei in the nobelium region for proton and neutron numbers of 92 ≤ Z ≤ 104 and 144 ≤ N ≤ 156, respectively. We use three different energy-density-functional (EDF) approaches, based on covariant, Skyrme, and Gogny functionals, each with two different parameter sets. A comparative analysis of the results obtained for quasiparticle spectra, odd–even and two-particle mass staggering, and moments of inertia allows us to identify single-particle and shell effects that are characteristic to these different models and to illustrate possible systematic uncertainties related to using themore » EDF modelling.« less

  7. Allelic variants of the amylose extender mutation of maize demonstrate phenotypic variation in starch structure resulting from modified protein–protein interactions

    PubMed Central

    Liu, Fushan; Ahmed, Zaheer; Lee, Elizabeth A.; Donner, Elizabeth; Liu, Qiang; Ahmed, Regina; Morell, Matthew K.; Emes, Michael J.; Tetlow, Ian J.

    2012-01-01

    amylose extender (ae−) starches characteristically have modified starch granule morphology resulting from amylopectin with reduced branch frequency and longer glucan chains in clusters, caused by the loss of activity of the major starch branching enzyme (SBE), which in maize endosperm is SBEIIb. A recent study with ae− maize lacking the SBEIIb protein (termed ae1.1 herein) showed that novel protein–protein interactions between enzymes of starch biosynthesis in the amyloplast could explain the starch phenotype of the ae1.1 mutant. The present study examined an allelic variant of the ae− mutation, ae1.2, which expresses a catalytically inactive form of SBEIIb. The catalytically inactive SBEIIb in ae1.2 lacks a 28 amino acid peptide (Val272–Pro299) and is unable to bind to amylopectin. Analysis of starch from ae1.2 revealed altered granule morphology and physicochemical characteristics distinct from those of the ae1.1 mutant as well as the wild-type, including altered apparent amylose content and gelatinization properties. Starch from ae1.2 had fewer intermediate length glucan chains (degree of polymerization 16–20) than ae1.1. Biochemical analysis of ae1.2 showed that there were differences in the organization and assembly of protein complexes of starch biosynthetic enzymes in comparison with ae1.1 (and wild-type) amyloplasts, which were also reflected in the composition of starch granule-bound proteins. The formation of stromal protein complexes in the wild-type and ae1.2 was strongly enhanced by ATP, and broken by phosphatase treatment, indicating a role for protein phosphorylation in their assembly. Labelling experiments with [γ-32P]ATP showed that the inactive form of SBEIIb in ae1.2 was phosphorylated, both in the monomeric form and in association with starch synthase isoforms. Although the inactive SBEIIb was unable to bind starch directly, it was strongly associated with the starch granule, reinforcing the conclusion that its presence in the

  8. Solution of the Skyrme-Hartree-Fock-Bogolyubov equations in the Cartesian deformed harmonic-oscillator basis.. (VII) HFODD (v2.49t): A new version of the program

    NASA Astrophysics Data System (ADS)

    Schunck, N.; Dobaczewski, J.; McDonnell, J.; Satuła, W.; Sheikh, J. A.; Staszczak, A.; Stoitsov, M.; Toivanen, P.

    2012-01-01

    format: tar.gz Programming language: FORTRAN-90 Computer: Intel Pentium-III, Intel Xeon, AMD-Athlon, AMD-Opteron, Cray XT4, Cray XT5 Operating system: UNIX, LINUX, Windows XP Has the code been vectorized or parallelized?: Yes, parallelized using MPI RAM: 10 Mwords Word size: The code is written in single-precision for the use on a 64-bit processor. The compiler option -r8 or +autodblpad (or equivalent) has to be used to promote all real and complex single-precision floating-point items to double precision when the code is used on a 32-bit machine. Classification: 17.22 Catalogue identifier of previous version: ADFL_v2_2 Journal reference of previous version: Comput. Phys. Comm. 180 (2009) 2361 External routines: The user must have access to the NAGLIB subroutine f02axe, or LAPACK subroutines zhpev, zhpevx, zheevr, or zheevd, which diagonalize complex hermitian matrices, the LAPACK subroutines dgetri and dgetrf which invert arbitrary real matrices, the LAPACK subroutines dsyevd, dsytrf and dsytri which compute eigenvalues and eigenfunctions of real symmetric matrices, the LINPACK subroutines zgedi and zgeco, which invert arbitrary complex matrices and calculate determinants, the BLAS routines dcopy, dscal, dgeem and dgemv for double-precision linear algebra and zcopy, zdscal, zgeem and zgemv for complex linear algebra, or provide another set of subroutines that can perform such tasks. The BLAS and LAPACK subroutines can be obtained from the Netlib Repository at the University of Tennessee, Knoxville: http://netlib2.cs.utk.edu/. Does the new version supersede the previous version?: Yes Nature of problem: The nuclear mean field and an analysis of its symmetries in realistic cases are the main ingredients of a description of nuclear states. Within the Local Density Approximation, or for a zero-range velocity-dependent Skyrme interaction, the nuclear mean field is local and velocity dependent. The locality allows for an effective and fast solution of the self

  9. Skyrme-Hartree-Fock-Bogoliubov nuclear mass formulas: crossing the 0.6 MeV accuracy threshold with microscopically deduced pairing.

    PubMed

    Goriely, S; Chamel, N; Pearson, J M

    2009-04-17

    We present a new Skyrme-Hartree-Fock-Bogoliubov nuclear-mass model in which the contact-pairing force is constructed from microscopic pairing gaps of symmetric nuclear matter and neutron matter calculated from realistic two- and three-body forces, with medium-polarization effects included. With the pairing being treated more realistically than in any of our earlier models, the rms deviation with respect to essentially all the available mass data falls to 0.581 MeV, the best value ever found within the mean-field framework. Since our Skyrme force is also constrained by the properties of pure neutron matter, this new model is particularly well suited for application to astrophysical problems involving a neutron-rich environment, such as the elucidation of the r process of nucleosynthesis, and the description of supernova cores and neutron-star crusts. PMID:19518625

  10. Space Science Education by Mathematica Demonstrations: Interactive Design of Moving Space Probe Elements Mechanics by Foldable and Extendable Structures for Space Applications

    NASA Astrophysics Data System (ADS)

    Kabai, S.; Bérczi, Sz.

    2010-03-01

    By the interactive Mathematica Demonstrations of the Wolfram Research several mechanics for space probe operation and motion simulations were studied as space robotics and science educational program.

  11. Neutron stars in the Bogomol'nyi-Prasad-Sommerfield Skyrme model: Mean-field limit versus full field theory

    NASA Astrophysics Data System (ADS)

    Adam, C.; Naya, C.; Sanchez-Guillen, J.; Vazquez, R.; Wereszczynski, A.

    2015-08-01

    Using a solitonic model of nuclear matter, the Bogomol'nyi-Prasad-Sommerfield (BPS) Skyrme model, we compare neutron stars obtained in the full field theory, where gravitational backreaction is completely taken into account, with calculations in a mean-field approximation using the Tolman-Oppenheimer-Volkoff approach. In the latter case, a mean-field-theory equation of state is derived from the original BPS field theory. We show that in the full field theory, where the energy density is nonconstant even at equilibrium, there is no universal and coordinate-independent equation of state of nuclear matter, in contrast to the mean-field approximation. We also study how neutron star properties are modified by going beyond mean-field theory and find that the differences between mean-field theory and exact results can be considerable. Further, we compare both exact and mean-field results with some theoretical and phenomenological constraints on neutron star properties, demonstrating thus the relevance of our model even in its most simple version.

  12. Description of the dipole giant resonance in heavy and superheavy nuclei within Skyrme random-phase approximation

    SciTech Connect

    Kleinig, W.; Nesterenko, V. O.; Kvasil, J.; Vesely, P.; Reinhard, P.-G.

    2008-10-15

    The E1(T=1) isovector dipole giant resonance (GDR) in heavy and superheavy deformed nuclei is analyzed over a sample of 18 rare-earth nuclei, four actinides, and three chains of superheavy elements (Z=102, 114, and 120). The basis of the description is the self-consistent separable random-phase approximation (SRPA) using the Skyrme force SLy6. The model well reproduces the experimental data in the rare-earth and actinide regions. The trend of the resonance peak energies follows the estimates from collective models, showing a bias to the volume mode for the rare-earth isotopes and a mix of volume and surface modes for actinides and superheavy elements. The widths of the GDR are mainly determined by the Landau fragmentation, which in turn is found to be strongly influenced by deformation. A deformation splitting of the GDR can contribute to about one-third of the width, and about 1 MeV further broadening can be associated with mechanisms beyond the SRPA description (e.g., escape widths and coupling with complex configurations)

  13. An extended CCR5-ECL2 peptide forms a helix that binds HIV-1 gp120 through non-specific hydrophobic interactions

    PubMed Central

    Kessler, Naama; Arshava, Boris; Naider, Fred; Scherf, Tali; Anglister, Jacob

    2015-01-01

    The chemokine receptor CCR5 serves as a co-receptor for the Human Immunodefficiency Virus type-1, HIV-1. The CCR5 N-terminal segment, the second extracellular loop (ECL2) and the transmembrane helices have been implicated in binding the envelope glycoprotein gp120. Peptides corresponding to the sequence of the putative ECL2 as well as peptides containing the ECL1 and ECL3 were found to inhibit HIV-1 infection. The aromatic residues in the C-terminal half of an ECL2 peptide were shown to interact with gp120. In the present study we determined that in aqueous buffer the segment Q188-Q194 in an elongated ECL2 peptide (R168 to K197) forms an amphiphilic helix, which corresponds to the beginning of the fifth transmembrane helix in the crystal structure of CCR5. Two dimensional Saturation Transfer Difference NMR spectroscopy and dynamic filtering studies revealed the involvement of Y187, F189, W190 and F193 of the helical segment, in the interaction with gp120. The crystal structure of CCR5 shows that the aromatic side chains of F189, W190 and F193 point away from the binding pocket and interact with the membrane or with an adjacent CCR5 molecule and therefore, could not interact with gp120 in the intact CCR5 receptor. We conclude that these three aromatic residues of ECL2 peptides interact with gp120 through hydrophobic interactions not representative of the interactions of the intact CCR5 receptor. The HIV-1 inhibition by ECL2 peptides as well as by ECL1 and ECL3 peptides and peptides corresponding to ECL2 of CXCR4, which serves as an alternative HIV-1 co-receptor, suggests that there is a hydrophobic surface in the envelope spike that could be a target for HIV-1 entry inhibitors. PMID:25703038

  14. Solution of the Skyrme-Hartree-Fock-Bogolyubov equations in the Cartesian deformed harmonic-oscillator basis. (IV) HFODD (v2.08i): a new version of the program

    NASA Astrophysics Data System (ADS)

    Dobaczewski, J.; Olbratowski, P.

    2004-04-01

    We describe the new version (v2.08i) of the code HFODD which solves the nuclear Skyrme-Hartree-Fock or Skyrme-Hartree-Fock-Bogolyubov problem by using the Cartesian deformed harmonic-oscillator basis. In the new version, all symmetries can be broken, which allows for calculations with angular frequency and angular momentum tilted with respect to the mass distribution. The new version contains an interface to the LAPACK subroutine ZHPEVX. Program summaryTitle of the program:HFODD (v2.08i) Catalogue number: ADTO Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADTO Reference in CPC for earlier version of program: J. Dobaczewski and J. Dudek, Comput. Phys. Commun. 131 (2000) 164 (v1.75r) Catalogue number of previous version: ADML Licensing provisions: none Does the new version supersede the previous one: yes Computers on which the program has been tested: SG Power Challenge L, Pentium-II, Pentium-III, AMD-Athlon Operating systems: UNIX, LINUX, Windows-2000 Programming language used: FORTRAN-77 and FORTRAN-90 Memory required to execute with typical data: 10 Mwords No. of bits in a word: The code is written in single-precision for the use on a 64-bit processor. The compiler option -r8 or +autodblpad (or equivalent) has to be used to promote all real and complex single-precision floating-point items to double precision when the code is used on a 32-bit machine. Has the code been vectorised?: Yes No. of bytes in distributed program, including test data, etc.: 265352 No. of lines in distributed program: 52656 Distribution format: tar gzip file Nature of physical problem: The nuclear mean-field and an analysis of its symmetries in realistic cases are the main ingredients of a description of nuclear states. Within the Local Density Approximation, or for a zero-range velocity-dependent Skyrme interaction, the nuclear mean-field is local and velocity dependent. The locality allows for

  15. Synthesis, structures and properties of Ag+ complexes containing polyphosphine ligands with extended Ag⋯C, N-O⋯π and C-H⋯π interactions

    NASA Astrophysics Data System (ADS)

    Huang, Ting-Hong; Yang, Hu; Yang, Guo; Li, Yanfen; Huang, Li-Li

    2016-08-01

    Based on ligands of N,N-bis((diphenylphosphino)methyl)benzenamine (pba), 4-(4-(bis((diphenylphosphino)methyl)amino)benzyl)-N-((diphenylphosphino)methyl)benzenamine (dptp) and N,N,N‧,N‧-tetrakis((diphenylphosphino)methyl)benzene-1,4-diamine (pbaa), three new silver(I) complexes [Ag(pba)2]ClO4 (1), [Ag2(dptp)2](ClO4)2·2DMF (2) and [Ag4(pbaa)(NO3)4]n (3), have been synthesized and characterized. Structural analysis reveals that all of these complexes contain the 1D infinite chains, with different variations in the weak interactions. Complexes 1 and 2 are interconnected by intermolecular C-H⋯π interactions to form 1D infinite chains and 2D networks, and the ordered-layer-lattic ClO4- and DMF in 2 are between 2D networks. For 3, the pbaa ligand adopts a tetradentate coordination mode to link two adjacent stair-like [Ag4O4] cores resulting in a 1D chain, respectively, with Ag⋯C, N-O⋯π and C-H⋯π interactions. All these show that phosphine ligands play an important role in the construction of interesting topological structures with different types of the weak interactions.

  16. Influence of counter-rotating interaction on quantum phase transition in Dicke-Hubbard lattice: an extended coherent-state approach

    NASA Astrophysics Data System (ADS)

    Lu, Yongchuan; Wang, Chen

    2016-07-01

    We investigate the ground-state behavior of the Dicke-Hubbard model including counter-rotating terms. By generalizing an extended coherent-state approach within mean-field theory, we self-consistently obtain the ground-state energy and delocalized order parameter. Localization-delocalization quantum phase transition of photons is clearly observed by breaking the parity symmetry. Particularly, Mott lobes are fully suppressed, and the delocalized order parameter shows monotonic enhancement by increasing qubit-cavity coupling strength, in sharp contrast to the Dicke-Hubbard model under rotating-wave approximation. Moreover, the corresponding phase boundaries are stabilized by decreasing photon hopping strength, compared to the Rabi-Hubbard model.

  17. The Integrability of an Extended Fifth-Order KdV Equation in 2+1 Dimensions: Painlevé Property, Lax Pair, Conservation Laws, and Soliton Interactions

    NASA Astrophysics Data System (ADS)

    Xu, Gui-qiong; Deng, Shu-fang

    2016-06-01

    In this article, we apply the singularity structure analysis to test an extended 2+1-dimensional fifth-order KdV equation for integrability. It is proven that the generalized equation passes the Painlevé test for integrability only in three distinct cases. Two of those cases are in agreement with the known results, and a new integrable equation is first given. Then, for the new integrable equation, we employ the Bell polynomial method to construct its bilinear forms, bilinear Bäcklund transformation, Lax pair, and infinite conversation laws systematically. The N-soliton solutions of this new integrable equation are derived, and the propagations and collisions of multiple solitons are shown by graphs.

  18. Coherent interaction of laser pulses in a resonant optically dense extended medium under the regime of strong field-matter coupling

    SciTech Connect

    Egorov, V.S.; Lebedev, V.N.; Mekhov, I.B.; Moroshkin, P.V.; Chekhonin, I.A.; Bagayev, S.N.

    2004-03-01

    The nonstationary pump-probe interaction between short laser pulses propagating in a resonant optically dense coherent medium is considered. Special attention is paid to the case where the density of two-level particles is high enough that a considerable part of the energy of relatively weak external laser fields can be coherently absorbed and reemitted by the medium. Thus, the field of the medium reaction plays a key role in the interaction processes, which leads to collective behavior of an atomic ensemble in the strongly coupled light-matter system. Such behavior results in fast excitation interchanges between the field and a medium in the form of optical ringing, which is analogous to polariton beating in solid-state optics. This collective oscillating response, which can be treated as successive beats between light wave packets of different group velocities, is shown to significantly affect the propagation and amplification of the probe field under its nonlinear interaction with a nearly copropagating pump pulse. Depending on the probe-pump time delay, the probe transmission spectra show the appearance of either a specific doublet or coherent dip. The widths of these features are determined by the density-dependent field-matter coupling coefficient and increase during the propagation. Besides that, the widths of the coherent features, which appear close to resonance in the broadband probe spectrum, exceed the absorption-line width, since under the strong-coupling regime, the frequency of optical ringing exceeds the rate of incoherent relaxation. Contrary to stationary strong-field effects, the density- and coordinate-dependent transmission spectra of the probe manifest the importance of collective oscillations and cannot be obtained in the framework of a single-atom model.

  19. The Bactofilin Cytoskeleton Protein BacM of Myxococcus xanthus Forms an Extended β-Sheet Structure Likely Mediated by Hydrophobic Interactions

    PubMed Central

    Xie, Kefang; Engelhardt, Harald; Bosch, Jürgen; Hoiczyk, Egbert

    2015-01-01

    Bactofilins are novel cytoskeleton proteins that are widespread in Gram-negative bacteria. Myxococcus xanthus, an important predatory soil bacterium, possesses four bactofilins of which one, BacM (Mxan_7475) plays an important role in cell shape maintenance. Electron and fluorescence light microscopy, as well as studies using over-expressed, purified BacM, indicate that this protein polymerizes in vivo and in vitro into ~3 nm wide filaments that further associate into higher ordered fibers of about 10 nm. Here we use a multipronged approach combining secondary structure determination, molecular modeling, biochemistry, and genetics to identify and characterize critical molecular elements that enable BacM to polymerize. Our results indicate that the bactofilin-determining domain DUF583 folds into an extended β-sheet structure, and we hypothesize a left-handed β-helix with polymerization into 3 nm filaments primarily via patches of hydrophobic amino acid residues. These patches form the interface allowing head-to-tail polymerization during filament formation. Biochemical analyses of these processes show that folding and polymerization occur across a wide variety of conditions and even in the presence of chaotropic agents such as one molar urea. Together, these data suggest that bactofilins are comprised of a structure unique to cytoskeleton proteins, which enables robust polymerization. PMID:25803609

  20. Scavengers of reactive γ-ketoaldehydes extend Caenorhabditis elegans lifespan and healthspan through protein-level interactions with SIR-2.1 and ETS-7.

    PubMed

    Nguyen, Thuy T; Caito, Samuel W; Zackert, William E; West, James D; Zhu, Shijun; Aschner, Michael; Fessel, Joshua P; Roberts, L Jackson

    2016-08-01

    Isoketals (IsoKs) are highly reactive γ-ketoaldehyde products of lipid peroxidation that covalently adduct lysine side chains in proteins, impairing their function. Using C. elegans as a model organism, we sought to test the hypothesis that IsoKs contribute to molecular aging through adduction and inactivation of specific protein targets, and that this process can be abrogated using salicylamine (SA), a selective IsoK scavenger. Treatment with SA extends adult nematode longevity by nearly 56% and prevents multiple deleterious age-related biochemical and functional changes. Testing of a variety of molecular targets for SA's action revealed the sirtuin SIR-2.1 as the leading candidate. When SA was administered to a SIR-2.1 knockout strain, the effects on lifespan and healthspan extension were abolished. The SIR-2.1-dependent effects of SA were not mediated by large changes in gene expression programs or by significant changes in mitochondrial function. However, expression array analysis did show SA-dependent regulation of the transcription factor ets-7 and associated genes. In ets-7 knockout worms, SA's longevity effects were abolished, similar to sir-2.1 knockouts. However, SA dose-dependently increases ets-7 mRNA levels in non-functional SIR-2.1 mutant, suggesting that both are necessary for SA's complete lifespan and healthspan extension. PMID:27514077

  1. Thermal properties of hot and dense matter with finite range interactions

    NASA Astrophysics Data System (ADS)

    Constantinou, Constantinos; Muccioli, Brian; Prakash, Madappa; Lattimer, James M.

    2015-08-01

    We explore the thermal properties of hot and dense matter using a model that reproduces the empirical properties of isospin symmetric and asymmetric bulk nuclear matter, optical-model fits to nucleon-nucleus scattering data, heavy-ion flow data in the energy range 0.5-2 GeV/A , and the largest well-measured neutron star mass of 2 M⊙ . This model, which incorporates finite range interactions through a Yukawa-type finite range force, is contrasted with a conventional zero range Skyrme model. Both models predict nearly identical zero-temperature properties at all densities and proton fractions, including the neutron star maximum mass, but differ in their predictions for heavy-ion flow data. We contrast their predictions of thermal properties, including their specific heats, and provide analytical formulas for the strongly degenerate and nondegenerate limits. We find significant differences in the results of the two models for quantities that depend on the density derivatives of nucleon effective masses. We show that a constant value for the ratio of the thermal components of pressure and energy density expressed as Γth=1 +(Pth/ɛth) , often used in simulations of proto-neutron stars and merging compact object binaries, fails to adequately describe results of either nuclear model. The region of greatest discrepancy extends from subsaturation densities to a few times the saturation density of symmetric nuclear matter. Our results suggest alternate approximations for the thermal properties of dense matter that are more realistic.

  2. Drug-Drug Interaction Studies of Paliperidone and Divalproex Sodium Extended-Release Tablets in Healthy Participants and Patients with Psychiatric Disorders.

    PubMed

    Remmerie, Bart; Ariyawansa, Jay; De Meulder, Marc; Coppola, Danielle; Berwaerts, Joris

    2016-06-01

    The objective of these 2 phase 1, open-label, 2-treatment, single-sequence studies was to evaluate the effect of repeated oral doses of divalproex sodium extended-release (ER) on the pharmacokinetics (PK) of a single dose of paliperidone ER in healthy participants (study 1), and the effect of multiple doses of paliperidone ER on the steady-state PK of valproic acid (VPA) in patients with psychiatric disorders (study 2), respectively. In study 1 healthy participants received, in a fixed sequential order, treatment A, paliperidone ER 12 mg (day 1); treatment B, VPA 1000 mg (2 × 500 mg divalproex sodium ER) once daily (days 5 to 18) and paliperidone ER 12 mg (day 15). In study 2 patients received treatment A, VPA (days 1-7); treatment B, VPA + paliperidone ER 12 mg (days 8-12). Divalproex sodium ER doses (study 2) were individualized such that systemic therapeutic VPA exposure from prior treatment was maintained on entry into the study. PK assessments were performed at prespecified time points (paliperidone days 1 and 15 [study 1]; VPA days 7 and 12 [study 2]). The oral bioavailability of paliperidone was increased by an estimated 51% (Cmax ) and 51%-52% (AUCs) when coadministered with divalproex sodium ER. No effect on the steady-state plasma concentration of VPA was observed following repeated coadministration with paliperidone ER: the 90%CI around the VPA exposure ratios for the 2 treatments was within the 80%-125% bioequivalence criteria for Cmax,ss and AUCτ . Both VPA and paliperidone ER were well tolerated, and no new safety concerns were identified. PMID:26412032

  3. Solution of the Skyrme-Hartree-Fock-Bogolyubov equations in the Cartesian deformed harmonic-oscillator basis.. (VI) HFODD (v2.40h): A new version of the program

    NASA Astrophysics Data System (ADS)

    Dobaczewski, J.; Satuła, W.; Carlsson, B. G.; Engel, J.; Olbratowski, P.; Powałowski, P.; Sadziak, M.; Sarich, J.; Schunck, N.; Staszczak, A.; Stoitsov, M.; Zalewski, M.; Zduńczuk, H.

    2009-11-01

    We describe the new version (v2.40h) of the code HFODD which solves the nuclear Skyrme-Hartree-Fock or Skyrme-Hartree-Fock-Bogolyubov problem by using the Cartesian deformed harmonic-oscillator basis. In the new version, we have implemented: (i) projection on good angular momentum (for the Hartree-Fock states), (ii) calculation of the GCM kernels, (iii) calculation of matrix elements of the Yukawa interaction, (iv) the BCS solutions for state-dependent pairing gaps, (v) the HFB solutions for broken simplex symmetry, (vi) calculation of Bohr deformation parameters, (vii) constraints on the Schiff moments and scalar multipole moments, (viii) the DT2h transformations and rotations of wave functions, (ix) quasiparticle blocking for the HFB solutions in odd and odd-odd nuclei, (x) the Broyden method to accelerate the convergence, (xi) the Lipkin-Nogami method to treat pairing correlations, (xii) the exact Coulomb exchange term, (xiii) several utility options, and we have corrected three insignificant errors. New version program summaryProgram title: HFODD (v2.40h) Catalogue identifier: ADFL_v2_2 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADFL_v2_2.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 79 618 No. of bytes in distributed program, including test data, etc.: 372 548 Distribution format: tar.gz Programming language: FORTRAN-77 and Fortran-90 Computer: Pentium-III, AMD-Athlon, AMD-Opteron Operating system: UNIX, LINUX, Windows XP Has the code been

  4. Isopiestic Determination of the Osmotic and Activity Coefficients of NaCl + SrCl2 + H2O at 298.15 K, and Representation with an Extended Ion-Interaction Model

    SciTech Connect

    Clegg, S L; Rard, J A; Miller, D G

    2004-11-09

    Isopiestic vapor-pressure measurements were made at 298.15 K for aqueous NaCl + SrCl{sub 2} solutions, using NaCl(aq) as the reference standard. The measurements for these ternary solutions were made at NaCl ionic strength fractions of y{sub 1} = 0.17066, 0.47366, and 0.82682 for the water activity range 0.9835 {ge} a{sub w} {ge} 0.8710. Our results, and those from two previous isopiestic studies, were combined and used with previously determined parameters for NaCl(aq) and those for SrCl{sub 2}(aq) determined here to evaluate the mixing parameters{sup S}{Theta}{sub Na,Sr} = (0.0562 {+-} 0.0007) kg {center_dot} mol{sup -1} and {Psi}{sub Na,Sr,Cl} = -(0.00705 {+-} 0.00017) kg{sup 2} {center_dot} mol{sup -2} for an extended form of Pitzer's ion-interaction model. These model parameters are valid for ionic strengths of I {le} 7.0 mol {center_dot} kg{sup -1}, where higher-order electrostatic effects have been included in the mixture model. If the fitting range is extended to the saturated solution molalities, then {sup S}{Theta}{sub Na,Sr} = (0.07885 {+-} 0.00195) kg {center_dot} mol{sup -1} and {Psi}{sub Na,Sr,Cl} = -(0.01230 {+-} 0.00033) kg{sup 2} {center_dot} mol{sup -2}. The extended ion-interaction model parameters obtained from available isopiestic data for SrCl{sub 2}(aq) at 298.15 K yield recommended values of the water activities and osmotic and activity coefficients.

  5. Extended Ewald summation technique

    NASA Astrophysics Data System (ADS)

    Kylänpää, Ilkka; Räsänen, Esa

    2016-09-01

    We present a technique to improve the accuracy and to reduce the computational labor in the calculation of long-range interactions in systems with periodic boundary conditions. We extend the well-known Ewald method by using a linear combination of screening Gaussian charge distributions instead of only one. This enables us to find faster converging real-space and reciprocal space summations. The combined simplicity and efficiency of our method is demonstrated, and the scheme is readily applicable to large-scale periodic simulations, classical as well as quantum. Moreover, apart from the required a priori optimization the method is straightforward to include in most routines based on the Ewald method within, e.g., density-functional, molecular dynamics, and quantum Monte Carlo calculations.

  6. Rice phytochrome-interacting factor protien OsPIFff14 represses OsDREB1B gene expression through an extended N-box and interacts preferentially with the active form of phytochrome B

    Technology Transfer Automated Retrieval System (TEKTRAN)

    DREB1/CBF genes, known as major regulators of plant stress responses, are rapidly and transiently induced by low temperatures. Using a Yeast one Hybrid screening, we identified a putative Phytochrome-Interacting bHLH Factor (OsPIF14), as binding to the OsDREB1B promoter. bHLH proteins are able to bi...

  7. Rice phytochrome-interacting factor protein OsPIFff14 represses OsDREB1B gene expression through an extended N-box and interacts preferentially with the active form of phytochrome B

    Technology Transfer Automated Retrieval System (TEKTRAN)

    DREB1/CBF genes, known as major regulators of plant stress responses, are rapidly and transiently induced by low temperatures. Using a Yeast one Hybrid screening, we identified a putative Phytochrome-Interacting bHLH Factor (OsPIF14), as binding to the OsDREB1B promoter. bHLH proteins are able to bi...

  8. Rice phytochrome-interacting factor protein OsPIF14 represses OsDREB1B gene expression through an extended N-box and interacts preferentially with the active form of phytochrome B.

    PubMed

    Cordeiro, André M; Figueiredo, Duarte D; Tepperman, James; Borba, Ana Rita; Lourenço, Tiago; Abreu, Isabel A; Ouwerkerk, Pieter B F; Quail, Peter H; Margarida Oliveira, M; Saibo, Nelson J M

    2016-02-01

    DREB1/CBF genes, known as major regulators of plant stress responses, are rapidly and transiently induced by low temperatures. Using a yeast one-hybrid screening, we identified a putative Phytochrome-Interacting bHLH Factor (OsPIF14), as binding to the OsDREB1B promoter. bHLH proteins are able to bind to hexameric E-box (CANNTG) or N-box (CACG(A/C)G) motifs, depending on transcriptional activity. We have shown that OsPIF14 binds to the OsDREB1B promoter through two N-boxes and that the flanking regions of the hexameric core are essential for protein-DNA interaction and stability. We also showed that OsPIF14 down-regulates OsDREB1B gene expression in rice protoplasts, corroborating the OsPIF14 repressor activity observed in the transactivation assays using Arabidopsis protoplasts. In addition, we showed that OsPIF14 is indeed a phytochrome interacting factor, which preferentially binds to the active form (Pfr) of rice phytochrome B. This raises the possibility that OsPIF14 activity might be modulated by light. However, we did not observe any regulation of the OsDREB1B gene expression by light under control conditions. Moreover, OsPIF14 gene expression was shown to be modulated by different treatments, such as drought, salt, cold and ABA. Interestingly, OsPIF14 showed also a specific cold-induced alternative splicing. All together, these results suggest the possibility that OsPIF14 is involved in cross-talk between light and stress signaling through interaction with the OsDREB1B promoter. Although in the absence of stress, OsDREB1B gene expression was not regulated by light, given previous reports, it remains possible that OsPIF14 has a role in light modulation of stress responses. PMID:26732823

  9. Rice phytochrome-interacting factor protein OsPIF14 represses OsDREB1B gene expression through an extended N-box and interacts preferentially with the active form of Phytochrome B

    PubMed Central

    Cordeiro, André M.; Figueiredo, Duarte D.; Tepperman, James; Borba, Ana Rita; Lourenço, Tiago; Abreu, Isabel A.; Ouwerkerk, Pieter B.F.; Quail, Peter H.; Oliveira, M. Margarida; Saibo, Nelson J. M.

    2016-01-01

    DREB1/CBF genes, known as major regulators of plant stress responses, are rapidly and transiently induced by low temperatures. Using a Yeast one Hybrid screening, we identified a putative Phytochrome-Interacting bHLH Factor (OsPIF14), as binding to the OsDREB1B promoter. bHLH proteins are able to bind to hexameric E-box (CANNTG) or N-box (CACG(A/C)G) motifs, depending on transcriptional activity. We have shown that OsPIF14 binds to the OsDREB1B promoter through two N-boxes and that the flanking regions of the hexameric core are essential for protein-DNA interaction and stability. We also showed that OsPIF14 down-regulates OsDREB1B gene expression in rice protoplasts, corroborating the OsPIF14 repressor activity observed in the transactivation assays using Arabidopsis protoplasts. In addition, we showed that OsPIF14 is indeed a Phytochrome Interacting Factor, which preferentially binds to the active form (Pfr) of rice phytochrome B. This raises the possibility that OsPIF14 activity might be modulated by light. However, we did not observe any regulation of the OsDREB1B gene expression by light under control conditions. Moreover, OsPIF14 gene expression was shown to be modulated by different treatments, such as drought, salt, cold and ABA. Interestingly, OsPIF14 showed also a specific cold-induced alternative splicing. All together, these results suggest the possibility that OsPIF14 is involved in cross-talk between light and stress signaling through interaction with the OsDREB1B promoter. Although in the absence of stress, OsDREB1B gene expression was not regulated by light, given previous reports, it remains possible that OsPIF14 has a role in light modulation of stress responses. PMID:26732823

  10. pp interactions in extended air showers

    NASA Astrophysics Data System (ADS)

    Kendi Kohara, A.; Ferreira, Erasmo; Kodama, Takeshi

    2015-08-01

    Applying the recently constructed analytic representation for the pp scattering amplitudes, we present a study of p-air cross sections, with comparison to the data from Extensive Air Shower (EAS) measurements. The amplitudes describe with precision all available accelerator data at ISR, SPS and LHC energies, and its theoretical basis, together with the very smooth energy dependence of parameters controlled by unitarity and dispersion relations, permit reliable extrapolation to higher energies and to asymptotic ranges. The comparison with cosmic ray data is very satisfactory in the whole pp energy interval from 1 to 100 TeV. High energy asymptotic behaviour of cross sections is investigated in view of the geometric scaling property of the amplitudes. The amplitudes predict that the proton does not behave as a black disk even at asymptotically high enegies, and we discuss possible non-trivial consequences of this fact for pA collision cross sections at higher energies.

  11. The (20)Ne interaction in extended matter

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Townsend, L. W.; Wong, M.; Schimmerling, W.

    1984-01-01

    Although heavy ion transport theory is developed to a relatively advanced stage, the present limitation in biomedical and electronic applications is the uncertainty in nuclear fragmentation parameters. The present status on Ne-20 beams is discussed and useful formulae are presented for future use in analysis of beam transport experiments.

  12. Axially deformed solution of the Skyrme-Hartree-Fock-Bogoliubov equations using the transformed harmonic oscillator basis (II) HFBTHO v2.00d: A new version of the program

    NASA Astrophysics Data System (ADS)

    Stoitsov, M. V.; Schunck, N.; Kortelainen, M.; Michel, N.; Nam, H.; Olsen, E.; Sarich, J.; Wild, S.

    2013-06-01

    of the transformed harmonic oscillator, which allows for an accurate description of deformation effects and pairing correlations in nuclei arbitrarily close to the particle drip lines. Solution method: The program uses the axial Transformed Harmonic Oscillator (THO) single- particle basis to expand quasi-particle wave functions. It iteratively diagonalizes the Hartree-Fock-Bogoliubov Hamiltonian based on generalized Skyrme-like energy densities and zero-range pairing interactions until a self-consistent solution is found. A previous version of the program was presented in: M.V. Stoitsov, J. Dobaczewski, W. Nazarewicz, P. Ring, Comput. Phys. Commun. 167 (2005) 43-63. Reasons for new version: Version 2.00d of HFBTHO provides a number of new options such as the optional breaking of reflection symmetry, the calculation of axial multipole moments, the finite temperature formalism for the HFB method, optimized multi-constraint calculations, the treatment of odd-even and odd-odd nuclei in the blocking approximation, and the framework for generalized energy density with arbitrary density-dependences. It is also the first version of HFBTHO to contain threading capabilities. Summary of revisions: The modified Broyden method has been implemented, Optional breaking of reflection symmetry has been implemented, The calculation of all axial multipole moments up to λ=8 has been implemented, The finite temperature formalism for the HFB method has been implemented, The linear constraint method based on the approximation of the Random Phase Approximation (RPA) matrix for multi-constraint calculations has been implemented, The blocking of quasi-particles in the Equal Filling Approximation (EFA) has been implemented, The framework for generalized energy density functionals with arbitrary density-dependence has been implemented, Shared memory parallelism via OpenMP pragmas has been implemented. Restrictions: Axial- and time-reversal symmetries are assumed. Unusual features: The user must

  13. Deformation properties with a finite-range simple effective interaction

    NASA Astrophysics Data System (ADS)

    Behera, B.; Viñas, X.; Routray, T. R.; Robledo, L. M.; Centelles, M.; Pattnaik, S. P.

    2016-08-01

    Deformed and spherical even-even nuclei are studied using a finite-range simple effective interaction within the Hartree-Fock-Bogoliubov mean-field approach. Different parameter sets of the interaction, corresponding to different incompressibility, are constructed by varying the exponent γ of the density in the traditional density-dependent term. Ten of the 12 parameters of these interactions are determined from properties of asymmetric nuclear matter and spin-polarized pure neutron matter. The two remaining parameters are fitted to reproduce the experimental binding energies known in 620 even-even nuclei using several variants of the rotational energy correction. The rms deviations for the binding energy depend on the value of γ and the way the rotational energy correction is treated but they can be as low as 1.56 MeV, a value competitive with other renowned effective interactions of Skyrme and Gogny type. Charge radii are compared to the experimental values of 313 even-even nuclei and the rms deviation is again comparable and even superior to the one of popular Skyrme and Gogny forces. Emphasis is given to the deformation properties predicted with these interactions by analyzing the potential energy surfaces for several well deformed nuclei and the fission barriers of some nuclei. Comparison of the results with the experimental information, where available, as well as with the results of the Gogny D1S force, shows satisfactory agreement.

  14. Correlation functions for extended mass galaxy clusters

    NASA Astrophysics Data System (ADS)

    Iqbal, Naseer; Ahmad, Naveel; Hamid, Mubashir; Masood, Tabasum

    2012-07-01

    The phenomenon of clustering of galaxies on the basis of correlation functions in an expanding Universe is studied by using equation of state, taking gravitational interaction between galaxies of extended nature into consideration. The partial differential equation for the extended mass structures of a two-point correlation function developed earlier by Iqbal, Ahmad & Khan is studied on the basis of assigned boundary conditions. The solution for the correlation function for extended structures satisfies the basic boundary conditions, which seem to be sufficient for understanding the phenomena, and provides a new insight into the gravitational clustering problem for extended mass structures.

  15. Quantum extended supersymmetries

    NASA Astrophysics Data System (ADS)

    Grigore, D. R.; Scharf, G.

    2004-09-01

    We analyse some quantum multiplets associated with extended supersymmetries. We study in detail the general form of the causal (anti)commutation relations. The condition of positivity of the scalar product imposes severe restrictions on the (quantum) model. It is problematic if one can find out quantum extensions of the standard model with extended supersymmetries.

  16. Logo and Extended Definition.

    ERIC Educational Resources Information Center

    Desilets, Brendan J.

    1986-01-01

    Describes use of the programing language "Logo" and the Apple II computer to teach high school students how to write extended definitions. By defining procedures in Logo for drawing simple geometric patterns, students learn that good definition requires precision, rewriting and, in complex tasks, recursion, an aspect of extended definition…

  17. Extended or Restricted Childhood?

    ERIC Educational Resources Information Center

    Richards, Colin

    2005-01-01

    This article discusses the Government's proposals for "extended" primary schools, an important element in the recently-published five-year plan for education. The author expresses concern that extended primary schools will not provide a variety of experiences, including "play" experiences for young children.

  18. Extended conformal field theories

    NASA Astrophysics Data System (ADS)

    Taormina, Anne

    1990-08-01

    Some extended conformal field theories are briefly reviewed. They illustrate how non minimal models of the Virasoro algebra (c≥1) can become minimal with respect to a larger algebra. The accent is put on N-extended superconformal algebras, which are relevant in superstring compactification.

  19. Isopiestic Determination of the Osmotic and Activity Coefficients of Li2SO4(aq) at T = 298.15 and 323.15 K, and Representation with an Extended Ion-interaction (Pitzer) model

    SciTech Connect

    Rard, J A; Clegg, S L; Palmer, D A

    2007-01-03

    Isopiestic vapor-pressure measurements were made for Li{sub 2}SO{sub 4}(aq) from 0.1069 to 2.8190 mol {center_dot} kg{sup -1} at 298.15 K, and from 0.1148 to 2.7969 mol {center_dot} kg{sup -1} at 323.15 K, with NaCl(aq) as the reference standard. Published thermodynamic data for this system were reviewed, recalculated for consistency, and critically assessed. The present results and the more reliable published results were used to evaluate the parameters of an extended version of Pitzer's ion-interaction model with an ionic-strength dependent third virial coefficient, as well as those of the standard Pitzer model, for the osmotic and activity coefficients at both temperatures. Published enthalpies of dilution at 298.15 K were also analyzed to yield the parameters of the ion-interaction models for the relative apparent molar enthalpies of dilution. The resulting models at 298.15 K are valid to the saturated solution molality of the thermodynamically stable phase Li{sub 2}SO{sub 4} {center_dot} H{sub 2}O(cr). Solubilities of Li{sub 2}SO{sub 4} {center_dot} H{sub 2}O(cr) at 298.15 K were assessed, and the selected value of m(sat.) = 3.13 {+-} 0.04 mol {center_dot} kg{sup -1} was used to evaluate the thermodynamic solubility product K{sub s}(Li{sub 2}SO{sub 4} {center_dot} H{sub 2}O, cr, 298.15 K) = (2.62 {+-} 0.19) and a CODATA-compatible standard molar Gibbs energy of formation {Delta}{sub f}G{sub m}{sup o} (Li{sub 2}SO{sub 4} {center_dot} H{sub 2}O, cr, 298.15 K) = -(1564.6 {+-} 0.5) kJ {center_dot} mol{sup -1}.

  20. Building Extended Families

    ERIC Educational Resources Information Center

    McKain, Barbara; McKain, Michael

    1970-01-01

    Discusses need for dissolution of the couple" relationship with substitution of the extended family which would permit each member to maintain individuality and to function on own merit. Suggests group living as preferable alternative. (CJ)

  1. Extended lifetime railgap switch

    SciTech Connect

    Cohn, D.B.; Mendoza, P.J.

    1988-02-02

    In a railgap switch of the type having an elongate blade electrode made of conductive material, an elongate housing made of insulating material for supporting the blade electrode and plate electrode in opposed relation extending in the same direction with the blade centered over the plate and separated therefrom by a gap, and a gas filling the housing and the gap, the gas being selected to breakdown and switch from a highly insulative state to a highly conductive state upon application of a high voltage across the blade and plate electrodes, the improvement is described comprising: forming the blade with laterally extending transverse wing portions at the edge of the blade and adjacent the gap so as to extend in spaced parallel relation to the surface of the plate, the blade generally following the contour thereof to form an inverted T-shape structure with the wing portions extending transversely of the elongate dimension of the blade. The wing portions terminating in a pair of spaced parallel edges extending along the elongate direction of the blade to thereby create two spaced elongate edges along which arcs form serving to divide the erosion effects of discharge between them, the current through each edge being one-half of that in single-edge devices with ablation wear reduced accordingly to give significantly larger switch lifetime. The blade and wing portions limiting ablation erosion of the edges in a direction generally align with the plate contour so that the edge-to-plate separation remains substantially constant.

  2. Extending quantum mechanics entails extending special relativity

    NASA Astrophysics Data System (ADS)

    Aravinda, S.; Srikanth, R.

    2016-05-01

    The complementarity between signaling and randomness in any communicated resource that can simulate singlet statistics is generalized by relaxing the assumption of free will in the choice of measurement settings. We show how to construct an ontological extension for quantum mechanics (QMs) through the oblivious embedding of a sound simulation protocol in a Newtonian spacetime. Minkowski or other intermediate spacetimes are ruled out as the locus of the embedding by virtue of hidden influence inequalities. The complementarity transferred from a simulation to the extension unifies a number of results about quantum non-locality, and implies that special relativity has a different significance for the ontological model and for the operational theory it reproduces. Only the latter, being experimentally accessible, is required to be Lorentz covariant. There may be certain Lorentz non-covariant elements at the ontological level, but they will be inaccessible at the operational level in a valid extension. Certain arguments against the extendability of QM, due to Conway and Kochen (2009) and Colbeck and Renner (2012), are attributed to their assumption that the spacetime at the ontological level has Minkowski causal structure.

  3. Extendable pipe crawler

    DOEpatents

    Hapstack, Mark

    1991-01-01

    A pipe crawler having a front leg assembly and a back leg assembly connected together by two air cylinders, each leg assembly having four extendable legs and a pair of actuators for sliding the extendable legs radially outward to increase the range of the legs when the pipe crawler enters a section of a pipe having a larger diameter. The crawler crawls by "inchworm"-like motion, the front leg assembly and back leg assembly alternately engaging and disengaging the wall of the pipe to hold the pipe crawler as the air cylinders alternately advance the front leg assembly and bring up the rear leg assembly. The pair of actuators of each leg assembly are parallel, adjacent and opposing acting so that each slides two adjacent extendable legs radially outward.

  4. Extendable pipe crawler

    DOEpatents

    Hapstack, M.

    1991-05-28

    A pipe crawler is described having a front leg assembly and a back leg assembly connected together by two air cylinders, each leg assembly having four extendable legs and a pair of actuators for sliding the extendable legs radially outward to increase the range of the legs when the pipe crawler enters a section of a pipe having a larger diameter. The crawler crawls by inchworm'-like motion, the front leg assembly and back leg assembly alternately engaging and disengaging the wall of the pipe to hold the pipe crawler as the air cylinders alternately advance the front leg assembly and bring up the rear leg assembly. The pair of actuators of each leg assembly are parallel, adjacent and opposing acting so that each slides two adjacent extendable legs radially outward. 5 figures.

  5. The Cassini Extended Mission

    NASA Astrophysics Data System (ADS)

    Seal, David A.; Buffington, Brent B.

    Based on the overwhelming success of the Cassini/Huygens 4-year tour of Saturn from July 2004 to June 2008, NASA Headquarters approved at least two years of extended mission for continued study of the target-rich Saturnian system. After a rigorous phase of science objective definition and trajectory design and analysis, the Cassini project initiated an efficient, scientifically intense and operationally challenging mission phase, including 60 orbits around Saturn, 26 close Titan flybys, and 10 close icy satellite flybys — including seven more flybys of Enceladus. At the conclusion of the 2-year extended mission, substantial operating margins should be present with some fascinating options for further extensions

  6. Modified Iterative Extended Hueckel. 1: Theory

    NASA Technical Reports Server (NTRS)

    Aronowitz, S.

    1980-01-01

    Iterative Extended Huekel is modified by inclusion of explicit effective internuclear and electronic interactions. The one electron energies are shown to obey a variational principle because of the form of the effective electronic interactions. The modifications permit mimicking of aspects of valence bond theory with the additional feature that the energies associated with valence bond type structures are explicitly calculated. In turn, a hybrid molecular, orbital valence, bond scheme is introduced which incorporates variant total molecular electronic density distributions similar to the way that Iterative Extended Hueckel incorporates atoms.

  7. An Extended Duopoly Game.

    ERIC Educational Resources Information Center

    Eckalbar, John C.

    2002-01-01

    Illustrates how principles and intermediate microeconomic students can gain an understanding for strategic price setting by playing a relatively large oligopoly game. Explains that the game extends to a continuous price space and outlines appropriate applications. Offers the Mathematica code to instructors so that the assumptions of the game can…

  8. Towards Extended Vantage Theory

    ERIC Educational Resources Information Center

    Glaz, Adam

    2010-01-01

    The applicability of Vantage Theory (VT), a model of (colour) categorization, to linguistic data largely depends on the modifications and adaptations of the model for the purpose. An attempt to do so proposed here, called Extended Vantage Theory (EVT), slightly reformulates the VT conception of vantage by capitalizing on some of the entailments of…

  9. Modelling extended chromospheres

    NASA Technical Reports Server (NTRS)

    Linsky, J. L.

    1986-01-01

    Attention is given to the concept that the warm, partially ionized plasma (presently called chromosphere) associated with such stars as Alpha Boo and Rho Per extends outwards at least several photospheric radii. Calculations are presented for the Mg II K line in light of two input model atmospheres. Specific predictions are deduced from the results obtained by each of the two models.

  10. EUVE Outsourced Extended Mission

    NASA Astrophysics Data System (ADS)

    Malina, R. F.; Biroscak, D.; Herz, A.; Christian, D.; Kaier, K.; Kaplan, G. C.; Lilly, S.; Quinn, T.; Stroozas, B.; Tucker, T.

    1996-05-01

    NASA has accepted an unsolicited proposal by the Center for EUV Atrophysics (CEA) at the University of California at Berkeley to manage spacecraft operations for the Extreme Ultraviolet Explorer (EUVE) extended mission. The proposal can serve as a model for university, government, and industry collaborations to respond to NASA's stated strategic goal to outsource all routine operations of scientific satellites to academia and industry. CEA has taken a conservative, low-cost approach to outsourcing that continues observatory operations, maintains the science return, and preserves the EUVE science archive. The Outsourced Extended Mission reduces yearly EUVE program costs, which may allow for a further extension of the science mission. This poster discusses the outsourced EUVE mission, its operations concept, NASA institutional support, and the roles and responsibilities of the government, university, and industry.

  11. Propelling Extended Objects

    ERIC Educational Resources Information Center

    Humbert, Richard

    2010-01-01

    A force acting on just part of an extended object (either a solid or a volume of a liquid) can cause all of it to move. That motion is due to the transmission of the force through the object by its material. This paper discusses how the force is distributed to all of the object by a gradient of stress or pressure in it, which creates the local…

  12. Extended Policies case

    EIA Publications

    2016-01-01

    The Annual Energy Outlook 2016 (AEO2016) Extended Policies case includes selected policies that go beyond current laws and regulations. Existing tax credits that have scheduled reductions and sunset dates are assumed to remain unchanged through 2040. Other efficiency policies, including corporate average fuel economy standards, appliance standards, and building codes, are expanded beyond current provisions; and the U.S. Environmental Protection Agency (EPA) Clean Power Plan (CPP) regulations that reduce carbon dioxide emissions from electric power generation are tightened after 2030.

  13. Time-Extended Multiple Group Counseling.

    ERIC Educational Resources Information Center

    Ficek, Daniel E.

    Time-extended groups provide the following: (1) they ease the need to get things started immediately, (2) they provide the opportunity for interaction to be carried to its natural end-point, (3) they allow a greater range of techniques to be experienced by members, (4) they increase the chances for therapeutic contact, (5) they allow participants…

  14. Dicyanometallates as Model Extended Frameworks

    PubMed Central

    2016-01-01

    We report the structures of eight new dicyanometallate frameworks containing molecular extra-framework cations. These systems include a number of hybrid inorganic–organic analogues of conventional ceramics, such as Ruddlesden–Popper phases and perovskites. The structure types adopted are rationalized in the broader context of all known dicyanometallate framework structures. We show that the structural diversity of this family can be understood in terms of (i) the charge and coordination preferences of the particular metal cation acting as framework node, and (ii) the size, shape, and extent of incorporation of extra-framework cations. In this way, we suggest that dicyanometallates form a particularly attractive model family of extended frameworks in which to explore the interplay between molecular degrees of freedom, framework topology, and supramolecular interactions. PMID:27057759

  15. Dicyanometallates as Model Extended Frameworks.

    PubMed

    Hill, Joshua A; Thompson, Amber L; Goodwin, Andrew L

    2016-05-11

    We report the structures of eight new dicyanometallate frameworks containing molecular extra-framework cations. These systems include a number of hybrid inorganic-organic analogues of conventional ceramics, such as Ruddlesden-Popper phases and perovskites. The structure types adopted are rationalized in the broader context of all known dicyanometallate framework structures. We show that the structural diversity of this family can be understood in terms of (i) the charge and coordination preferences of the particular metal cation acting as framework node, and (ii) the size, shape, and extent of incorporation of extra-framework cations. In this way, we suggest that dicyanometallates form a particularly attractive model family of extended frameworks in which to explore the interplay between molecular degrees of freedom, framework topology, and supramolecular interactions. PMID:27057759

  16. Extended Testability Analysis Tool

    NASA Technical Reports Server (NTRS)

    Melcher, Kevin; Maul, William A.; Fulton, Christopher

    2012-01-01

    The Extended Testability Analysis (ETA) Tool is a software application that supports fault management (FM) by performing testability analyses on the fault propagation model of a given system. Fault management includes the prevention of faults through robust design margins and quality assurance methods, or the mitigation of system failures. Fault management requires an understanding of the system design and operation, potential failure mechanisms within the system, and the propagation of those potential failures through the system. The purpose of the ETA Tool software is to process the testability analysis results from a commercial software program called TEAMS Designer in order to provide a detailed set of diagnostic assessment reports. The ETA Tool is a command-line process with several user-selectable report output options. The ETA Tool also extends the COTS testability analysis and enables variation studies with sensor sensitivity impacts on system diagnostics and component isolation using a single testability output. The ETA Tool can also provide extended analyses from a single set of testability output files. The following analysis reports are available to the user: (1) the Detectability Report provides a breakdown of how each tested failure mode was detected, (2) the Test Utilization Report identifies all the failure modes that each test detects, (3) the Failure Mode Isolation Report demonstrates the system s ability to discriminate between failure modes, (4) the Component Isolation Report demonstrates the system s ability to discriminate between failure modes relative to the components containing the failure modes, (5) the Sensor Sensor Sensitivity Analysis Report shows the diagnostic impact due to loss of sensor information, and (6) the Effect Mapping Report identifies failure modes that result in specified system-level effects.

  17. Extended cooperative control synthesis

    NASA Technical Reports Server (NTRS)

    Davidson, John B.; Schmidt, David K.

    1994-01-01

    This paper reports on research for extending the Cooperative Control Synthesis methodology to include a more accurate modeling of the pilot's controller dynamics. Cooperative Control Synthesis (CCS) is a methodology that addresses the problem of how to design control laws for piloted, high-order, multivariate systems and/or non-conventional dynamic configurations in the absence of flying qualities specifications. This is accomplished by emphasizing the parallel structure inherent in any pilot-controlled, augmented vehicle. The original CCS methodology is extended to include the Modified Optimal Control Model (MOCM), which is based upon the optimal control model of the human operator developed by Kleinman, Baron, and Levison in 1970. This model provides a modeling of the pilot's compensation dynamics that is more accurate than the simplified pilot dynamic representation currently in the CCS methodology. Inclusion of the MOCM into the CCS also enables the modeling of pilot-observation perception thresholds and pilot-observation attention allocation affects. This Extended Cooperative Control Synthesis (ECCS) allows for the direct calculation of pilot and system open- and closed-loop transfer functions in pole/zero form and is readily implemented in current software capable of analysis and design for dynamic systems. Example results based upon synthesizing an augmentation control law for an acceleration command system in a compensatory tracking task using the ECCS are compared with a similar synthesis performed by using the original CCS methodology. The ECCS is shown to provide augmentation control laws that yield more favorable, predicted closed-loop flying qualities and tracking performance than those synthesized using the original CCS methodology.

  18. The extended abdominoplasty.

    PubMed

    Shestak, Kenneth C

    2014-10-01

    This article illustrates the author's approach of directly excising adipose tissue excess in the lateral and posterior hip region by extending the lateral extent of the horizontal incision in a full abdominoplasty toward the posterior axillary line to produce a superior contour in this region. It is most applicable in patients with a significant adipose tissue excess in the lateral hip area that produces an outward convexity seen in the frontal, posterior, or oblique view. Such an excess represents a soft tissue "dog ear" composed of skin, and adipose tissue both deep and superficial to the superficial fascial system. PMID:25283456

  19. Extended Wordsearches in Chemistry

    NASA Astrophysics Data System (ADS)

    Cotton, Simon

    1998-04-01

    Students can be encouraged to develop their factual knowledge by use of puzzles. One strategy described here is the extended wordsearch, where the wordsearch element generates a number of words or phrases from which the answers to a series of questions are selected. The wordsearch can be generated with the aid of computer programs, though in order to make them suitable for students with dyslexia or other learning difficulties, a simpler form is more appropriate. These problems can be employed in a variety of contexts, for example, as topic tests and classroom end-of-lesson fillers. An example is provided in the area of calcium chemistry. Sources of suitable software are listed.

  20. Extended conformal algebras

    NASA Astrophysics Data System (ADS)

    Bouwknegt, Peter

    1988-06-01

    We investigate extensions of the Virasoro algebra by a single primary field of integer or halfinteger conformal dimension Δ. We argue that for vanishing structure constant CΔΔΔ, the extended conformal algebra can only be associative for a generic c-value if Δ=1/2, 1, 3/2, 2 or 3. For the other Δ<=5 we compute the finite set of allowed c-values and identify the rational solutions. The case CΔΔΔ≠0 is also briefly discussed. I would like to thank Kareljan Schoutens for discussions and Sander Bais for a careful reading of the manuscript.

  1. Spatially Extended Modelocking

    NASA Technical Reports Server (NTRS)

    Fork, Richard L.; Diffey, William M.; Gamble, Lisa; Keys, Andrew S.

    1999-01-01

    We examine the properties of optical fields that are extended in space over transverse dimensions of several meters or more in terms of both multiple spatial modes and also multiple temporal modes. We focus attention on the task of producing and maintaining well defined phase relationships for the set of spatial and temporal modes. In particular, we address operating regimes where the optical fields are not confined within an optical resonator, but still have well defined phase relations through the use of optical field sensing and correction techniques. Special applications of interest occur in safe beaming of optical power and in approaching optical intensities capable of producing nonlinear phenomena in the vacuum.

  2. Optional Extended Year Program. FEEDBACK.

    ERIC Educational Resources Information Center

    Washington, Wanda

    The Optional Extended Year (OEY) program was initiated in Texas in 1995 and was first implemented in the Austin Independent School District (AISD) in 1996. The OEY is designed to add an extended school year and reduce student retention through four school-day options: (1) extended day; (2) extended week; (3) intersessions for year-round schools;…

  3. Pair extended coupled cluster doubles

    SciTech Connect

    Henderson, Thomas M.; Scuseria, Gustavo E.; Bulik, Ireneusz W.

    2015-06-07

    The accurate and efficient description of strongly correlated systems remains an important challenge for computational methods. Doubly occupied configuration interaction (DOCI), in which all electrons are paired and no correlations which break these pairs are permitted, can in many cases provide an accurate account of strong correlations, albeit at combinatorial computational cost. Recently, there has been significant interest in a method we refer to as pair coupled cluster doubles (pCCD), a variant of coupled cluster doubles in which the electrons are paired. This is simply because pCCD provides energies nearly identical to those of DOCI, but at mean-field computational cost (disregarding the cost of the two-electron integral transformation). Here, we introduce the more complete pair extended coupled cluster doubles (pECCD) approach which, like pCCD, has mean-field cost and reproduces DOCI energetically. We show that unlike pCCD, pECCD also reproduces the DOCI wave function with high accuracy. Moreover, pECCD yields sensible albeit inexact results even for attractive interactions where pCCD breaks down.

  4. Lunar Prospector Extended Mission

    NASA Technical Reports Server (NTRS)

    Folta, David; Beckman, Mark; Lozier, David; Galal, Ken

    1999-01-01

    The National Aeronautics and Space Administration (NASA) selected Lunar Prospector as one of the discovery missions to conduct solar system exploration science investigations. The mission is NASA's first lunar voyage to investigate key science objectives since Apollo and was launched in January 1998. In keeping with discovery program requirements to reduce total mission cost and utilize new technology, Lunar Prospector's mission design and control focused on the use of innovative and proven trajectory analysis programs. As part of this effort, the Ames Research Center and the Goddard Space Flight Center have become partners in the Lunar Prospector trajectory team to provide the trajectory analysis, maneuver planning, orbit determination support, and product generation. At the end of 1998, Lunar Prospector completed its one-year primary mission at 100 km altitude above the lunar surface. On December 19, 1998, Lunar Prospector entered the extended mission phase. Initially the mission orbit was lowered from 100 km to a mean altitude of 40 km. The altitude of Lunar Prospector varied between 25 and 55 km above the mean lunar geode due to lunar potential effects. After one month, the lunar potential model was updated based upon the new tracking data at 40 km. On January 29, 1999, the altitude was lowered again to a mean altitude of 30 km. This altitude varies between 12 and 48 km above the mean lunar geode. Since the minimum altitude is very close to the mean geode, various approaches were employed to get accurate lunar surface elevation including Clementine altimetry and line of sight analysis. Based upon the best available terrain maps, Lunar Prospector will reach altitudes of 8 km above lunar mountains in the southern polar and far side regions. This extended mission phase of six months will enable LP to obtain science data up to 3 orders of magnitude better than at the mission orbit. This paper details the trajectory design and orbit determination planning, and

  5. Lunar Prospector Extended Mission

    NASA Technical Reports Server (NTRS)

    Folta, David; Beckman, Mark; Lozier, David; Galal, Ken

    1999-01-01

    The National Aeronautics and Space Administration (NASA) selected Lunar Prospector (LP) as one of the discovery missions to conduct solar system exploration science investigations. The mission is NASA's first lunar voyage to investigate key science objectives since Apollo and was launched in January 1998. In keeping with discovery program requirements to reduce total mission cost and utilize new technology, Lunar Prospector's mission design and control focused on the use of innovative and proven trajectory analysis programs. As part of this effort, the Ames Research Center and the Goddard Space Flight Center have become partners in the Lunar Prospector trajectory team to provide the trajectory analysis, maneuver planning, orbit determination support, and product generation. At the end of 1998, Lunar Prospector completed its one-year primary mission at 100 km altitude above the lunar surface. On December 19, 1998, Lunar Prospector entered the extended mission phase. Initially the mission orbit was lowered from 100 km to a mean altitude of 40 km. The altitude of Lunar Prospector varied between 25 and 55 km above the mean lunar geode due to lunar potential effects. After one month, the lunar potential model was updated based upon the new tracking data at 40 km. On January 29, 1999, the altitude was lowered again to a mean altitude of 30 km. This altitude varies between 12 and 48 km above the mean lunar geode. Since the minimum altitude is very close to the mean geode, various approaches were employed to get accurate lunar surface elevation including Clementine altimetry and line of sight analysis. Based upon the best available terrain maps, Lunar Prospector will reach altitudes of 8 km above lunar mountains in the southern polar and far side regions. This extended mission phase of six months will enable LP to obtain science data up to 3 orders of magnitude better than at the mission orbit. This paper details the trajectory design and orbit determination planning and

  6. Lunar Prospector Extended Mission

    NASA Astrophysics Data System (ADS)

    Folta, David; Beckman, Mark; Lozier, David; Galal, Ken

    1999-05-01

    The National Aeronautics and Space Administration (NASA) selected Lunar Prospector (LP) as one of the discovery missions to conduct solar system exploration science investigations. The mission is NASA's first lunar voyage to investigate key science objectives since Apollo and was launched in January 1998. In keeping with discovery program requirements to reduce total mission cost and utilize new technology, Lunar Prospector's mission design and control focused on the use of innovative and proven trajectory analysis programs. As part of this effort, the Ames Research Center and the Goddard Space Flight Center have become partners in the Lunar Prospector trajectory team to provide the trajectory analysis, maneuver planning, orbit determination support, and product generation. At the end of 1998, Lunar Prospector completed its one-year primary mission at 100 km altitude above the lunar surface. On December 19, 1998, Lunar Prospector entered the extended mission phase. Initially the mission orbit was lowered from 100 km to a mean altitude of 40 km. The altitude of Lunar Prospector varied between 25 and 55 km above the mean lunar geode due to lunar potential effects. After one month, the lunar potential model was updated based upon the new tracking data at 40 km. On January 29, 1999, the altitude was lowered again to a mean altitude of 30 km. This altitude varies between 12 and 48 km above the mean lunar geode. Since the minimum altitude is very close to the mean geode, various approaches were employed to get accurate lunar surface elevation including Clementine altimetry and line of sight analysis. Based upon the best available terrain maps, Lunar Prospector will reach altitudes of 8 km above lunar mountains in the southern polar and far side regions. This extended mission phase of six months will enable LP to obtain science data up to 3 orders of magnitude better than at the mission orbit. This paper details the trajectory design and orbit determination planning and

  7. Reduced Extended MHD

    NASA Astrophysics Data System (ADS)

    Morrison, P. J.; Abdelhamid, H. M.; Grasso, D.; Hazeltine, R. D.; Lingam, M.; Tassi, E.

    2015-11-01

    Over the years various reduced fluid models have been obtained for modeling plasmas, with the goal of capturing important physics while maintaining computability. Such models have included the physics contained in various generalizations of Ohm's law, including Hall drift and electron inertia. In a recent publication it was shown that full 3D extended MHD is a Hamiltonian system by finding its noncanonical Poisson bracket. Subsequently, this bracket was shown to be derivable from that for Hall MHD by a series of remarkable transformations, which greatly simplifies the proof of the Jacobi identity and allows one to immediately obtain generalizations of the helicity and cross helicity. In this poster we use this structure to obtain exact reduced fluid models with the effects of full two-fluid theory. Results of numerical computations of collisionless reconnection using an exact reduced 4-field model will be presented and analytical comparisons of mode structure of previous reduced models will be made.

  8. An extended Lagrangian method

    NASA Technical Reports Server (NTRS)

    Liou, Meng-Sing

    1992-01-01

    A unique formulation of describing fluid motion is presented. The method, referred to as 'extended Lagrangian method', is interesting from both theoretical and numerical points of view. The formulation offers accuracy in numerical solution by avoiding numerical diffusion resulting from mixing of fluxes in the Eulerian description. Meanwhile, it also avoids the inaccuracy incurred due to geometry and variable interpolations used by the previous Lagrangian methods. Unlike the Lagrangian method previously imposed which is valid only for supersonic flows, the present method is general and capable of treating subsonic flows as well as supersonic flows. The method proposed in this paper is robust and stable. It automatically adapts to flow features without resorting to clustering, thereby maintaining rather uniform grid spacing throughout and large time step. Moreover, the method is shown to resolve multi-dimensional discontinuities with a high level of accuracy, similar to that found in one-dimensional problems.

  9. An extended Lagrangian method

    NASA Technical Reports Server (NTRS)

    Liou, Meng-Sing

    1993-01-01

    A unique formulation of describing fluid motion is presented. The method, referred to as 'extended Lagrangian method', is interesting from both theoretical and numerical points of view. The formulation offers accuracy in numerical solution by avoiding numerical diffusion resulting from mixing of fluxes in the Eulerian description. Meanwhile, it also avoids the inaccuracy incurred due to geometry and variable interpolations used by the previous Lagrangian methods. The present method is general and capable of treating subsonic flows as well as supersonic flows. The method proposed in this paper is robust and stable. It automatically adapts to flow features without resorting to clustering, thereby maintaining rather uniform grid spacing throughout and large time step. Moreover, the method is shown to resolve multidimensional discontinuities with a high level of accuracy, similar to that found in 1D problems.

  10. Transcervical extended mediastinal lymphadenectomy.

    PubMed

    Zielinski, Marcin; Kuzdzal, Jaroslaw; Nabialek, Tomasz; Hauer, Lukasz; Pankowski, Juliusz; Dziadzio, Bogdan

    2006-01-01

    Transcervical extended mediastinal lymphadenectomy (TEMLA) is a new procedure for bilateral excision of all nodal stations of the mediastinum, except for the pulmonary ligament nodes (station 9) and the most distal left lower paratracheal nodes (station 4L). The procedure is performed through a transverse 5-8 cm incision in the neck with elevation of the sternum with a traction device facilitating the access to the mediastinum. Most of the procedure is performed with an open technique, while the removal of the subcarinal (station 7) and periesophageal nodes (station 8) is performed with the mediastinoscopy assisted technique and excision of the paraaortic nodes (station 6), the aorta-pulmonary window nodes (station 5) and, sometimes, the prevascular nodes (station 3A) is performed with the aid of a videothoracoscope introduced to the mediastinum through the neck incision, without violating the pleura. PMID:24413333