WorldWideScience

Sample records for superexchange coupling interaction

  1. Ultracoherent operation of spin qubits with superexchange coupling

    Science.gov (United States)

    Rančić, Marko J.; Burkard, Guido

    2017-11-01

    With the use of nuclear-spin-free materials such as silicon and germanium, spin-based quantum bits (qubits) have evolved to become among the most coherent systems for quantum information processing. The new frontier for spin qubits has therefore shifted to the ubiquitous charge noise and spin-orbit interaction, which are limiting the coherence times and gate fidelities of solid-state qubits. In this paper we investigate superexchange, as a means of indirect exchange interaction between two single electron spin qubits, each embedded in a single semiconductor quantum dot (QD), mediated by an intermediate, empty QD. Our results suggest the existence of "supersweet spots", in which the qubit operations implemented by superexchange interaction are simultaneously first-order-insensitive to charge noise and to errors due to spin-orbit interaction. The proposed spin-qubit architecture is scalable and within the manufacturing capabilities of semiconductor industry.

  2. Controlling Correlated Tunneling and Superexchange Interactions with ac-Driven Optical Lattices

    International Nuclear Information System (INIS)

    Chen, Yu-Ao; Nascimbene, Sylvain; Aidelsburger, Monika; Atala, Marcos; Trotzky, Stefan; Bloch, Immanuel

    2011-01-01

    The dynamical control of tunneling processes of single particles plays a major role in science ranging from Shapiro steps in Josephson junctions to the control of chemical reactions via light in molecules. Here we show how such control can be extended to the regime of correlated tunneling of strongly interacting particles. Through a periodic modulation of a biased tunnel contact, we have been able to coherently control single-particle and correlated two-particle hopping processes. We have furthermore been able to extend this control to superexchange spin interactions in the presence of a magnetic-field gradient. Such photon-assisted superexchange processes constitute a novel approach to realize arbitrary XXZ spin models in ultracold quantum gases, where transverse and Ising-type spin couplings can be fully controlled in magnitude and sign.

  3. Effect of orbital symmetry on the anisotropic superexchange interaction

    International Nuclear Information System (INIS)

    Kim, Beom Hyun; Min, B I

    2011-01-01

    Employing the microscopic superexchange model incorporating the effect of spin-orbit interaction, we have investigated the Dzyaloshinsky-Moriya (DM) interaction in perovskite transition-metal (TM) oxides and explored the interplay between the DM interaction and the TM-3d orbital symmetry. For d 3 and d 5 systems with isotropic orbital symmetry, the DM vectors are well described by a simple symmetry analysis considering only the bond geometry. In contrast, the DM interaction for d 4 systems with anisotropic orbital symmetry shows slightly different behavior, which does not obey simple symmetry analysis. The direction as well as the strength of the DM vector varies depending on the occupied orbital shape. We have understood this behavior based on the orbital symmetry induced by local crystal field variation.

  4. Magnetic-superexchange interactions of uranium(IV) chloride-addition complexes with amides, 2

    International Nuclear Information System (INIS)

    Miyake, Chie; Hinatsu, Yukio; Imoto, Shosuke

    1983-01-01

    The magnetic susceptibilities of five cyclic amide (lactam)-addition complexes of uranium(IV) chloride were measured between room temperature and 2 K. Magnetic-exchange interaction was found only for N-methyl-substituted amide complexes, and a dimer structure was assumed for them on the basis of their chemical properties. Treating interdimer interaction with a molecular-field approximation, the magnetic susceptibilities were calculated to be in good agreement with the experimental results in the temperature region of the maxima in chi sub(A). The transmission of antiparallel spin coupling via the π orbitals of the bridging amide ligands is proposed to explain the strong intradimer superexchange interaction for the uranium(IV) chloride-amide complexes with the magnetic-susceptibility maximum. (author)

  5. Spin-orbital superexchange physics emerging from interacting oxygen molecules in KO2

    International Nuclear Information System (INIS)

    Solovyev, I V

    2008-01-01

    We propose that the spin-orbital-lattice coupled phenomena, widely known for the transition-metal oxides, can be realized in molecular solids, comprising of orbitally degenerate magnetic O 2 - ions. KO 2 is one such system. Using the first-principles electronic structure calculations, we set-up an effective spin-orbital superexchange model for the low-energy molecular bands and argue that many anomalous properties of KO 2 indeed replicate the status of its orbital system in different temperature regimes

  6. Moessbauer studies of superexchange interactions in NiFe sub 2 O sub 4

    CERN Document Server

    Kim, S J; Kim, C S; Lee, S W

    2000-01-01

    NiFe sub 2 O sub 4 has been studied using Moessbauer spectroscopy and X-ray diffraction. The crystal was found to have a inverse cubic spinel structure with the lattice constant a sub 0 =8.326+-0.003 A. Moessbauer spectra of NiFe sub 2 O sub 4 was obtained at various absorber temperatures from 13 K to the Neel temperature. The Moessbauer spectra consisted of two sets of six lines corresponding to Fe sup + sup 3 at the tetrahedral (A) and the octahedral (B) sites. The temperature dependence of the magnetic hyperfine fields at sup 5 sup 7 Fe nuclei at the tetrahedral (A) and the octahedral (B) sites was analyzed by the Neel theory of ferrimagnetism. The intersublattice A-O-B and intrasublattice A-O-A superexchange interactions were found to be antiferromagnetic with strengths of J sub A sub - sub B =-25.0 k sub B and J sub A sub - sub A =-4.0 K sub B , respectively, while the intrasublattice B-O-B superexchange interaction is ferromagnetic with a strength J sub B sub - sub B =4.2 k sub B.

  7. Assessing the performance of the random phase approximation for exchange and superexchange coupling constants in magnetic crystalline solids

    DEFF Research Database (Denmark)

    Olsen, Thomas

    2017-01-01

    The random phase approximation (RPA) for total energies has previously been shown to provide a qualitatively correct description of static correlation in molecular systems, where density functional theory (DFT) with local functionals are bound to fail. This immediately poses the question of whether...... the RPA is also able to capture the correct physics of strongly correlated solids such asMott insulators. Due to strong electron localization, magnetic interactions in such systems are dominated by superexchange, which in the simplest picture can be regarded as the analog of static correlation...... for molecules. In this paper, we investigate the performance of the RPA for evaluating both superexchange and direct exchange interactions in the magnetic solids NiO, MnO, Na3Cu2SbO6, Sr2CuO3, Sr2CuTeO6, and a monolayer of CrI3, which were chosen to represent a broad variety of magnetic interactions...

  8. The superexchange interactions and magnetic ordering in low-dimentional ludwigite Ni_5GeB_2O_1_0

    International Nuclear Information System (INIS)

    Sofronova, S.N.; Bezmaternykh, L.N.; Eremin, E.V.; Nazarenko, I.I.; Volkov, N.V.; Kartashev, A.V.; Moshkina, E.M.

    2016-01-01

    The ludwigite Ni_5Ge(BO_5)_2 belongs to a family of oxyborates which have low-dimensional subunits in the form of three-leg ladders unit structure. This material was studied by magnetic and thermodynamic measurements. Ni_5Ge(BO_5)_2 does not show full long-range magnetic order, but one goes into a partial ordering or spin-glass state at 87 K. The superexchange interactions were calculated in the framework of a simple indirect coupling model. Different models of magnetic structure of Ni_5Ge(BO_5)_2 and its unique magnetic behaviour was discussed. - Highlights: • The single crystals of Ni_5Ge(BO_5)_2 with a ludwigite structure were grown. • Magnetic and the specific heat measurements were performed. • The calculation of the exchange interactions shows a competition between interactions. • The magnetic behaviour corresponds to ions moments part freezing or spin-glass state. • We propose two models of magnetic ordering in Ni_5Ge(BO_5)_2.

  9. Superexchange and spin-glass formation in semimagnetic semiconductors

    Science.gov (United States)

    Rusin, Tomasz M.

    1996-05-01

    The Mn-Mn superexchange interaction in semimagnetic semiconductors A1-xMnxB (where A=Zn, Cd and B=S, Se, Te) is studied within the three-level model of the band structure. We focus on the dependence of the interaction on the interion distance Jdd(r)=J0f(r). In the present work, the function f(r) is obtained analytically. This, only weakly material-dependent function is found to decrease with Mn-Mn distance much slower than its Gaussian approximation derived previously. The exact form of the decay of the superexchange can be approximated by a power law J0r-8.5. This is close to an experimental result, J0r-6.8, determined on the basis of the spin-glass transition temperature on the composition.

  10. Influence of Dzyaloshinskii-Moriya and Kaplan-Shekhtman-Entinwohlman-Aharony superexchange interactions on ground state properties of the one-dimensional spin-Peilers model in open chain

    International Nuclear Information System (INIS)

    Liu Hai-Lian; Huang Xian-Shan; Wang Zhi-Guo; Shi Yun-Long

    2010-01-01

    The effects of the Dzyaloshinskii—Moriya (DM) and the Kaplan—Shekhtman—Entinwohlman—Aharony (KSEA) superexchange interactions on the ground state properties of the one-dimensional spin-Peilers system in open chain are studied by using the Lanczos numerical method. The study concentrates mainly on the influence of systemic dimerisation in open chain. The results show that systemic ground state energy density varies with dimerisation parameter δ in different DM interactions, and there exists a special point δ c where the DM interaction has no influence on the systemic dimerisation, no matter whether the DM interaction is relative or irrelative to systemic dimerisation (η = 1 or η = 0). The KSEA interaction has no fixed special point, but the points of intersection are dense relatively in a certain numberical value range, and sparse in other numberical value ranges. So we can conclude that the antisymmetric anisotropy DM interaction differs from the symmetric anisotropy KSEA interaction, but they are analogous in the sense of the influence of systemic dimerisation in open chain

  11. Monte Carlo study of the double and super-exchange model with lattice distortion

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, J R; Vallejo, E; Navarro, O [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-360, 04510 Mexico D. F. (Mexico); Avignon, M, E-mail: jrsuarez@iim.unam.m [Institut Neel, Centre National de la Recherche Scientifique (CNRS) and Universite Joseph Fourier, BP 166, 38042 Grenoble Cedex 9 (France)

    2009-05-01

    In this work a magneto-elastic phase transition was obtained in a linear chain due to the interplay between magnetism and lattice distortion in a double and super-exchange model. It is considered a linear chain consisting of localized classical spins interacting with itinerant electrons. Due to the double exchange interaction, localized spins tend to align ferromagnetically. This ferromagnetic tendency is expected to be frustrated by anti-ferromagnetic super-exchange interactions between neighbor localized spins. Additionally, lattice parameter is allowed to have small changes, which contributes harmonically to the energy of the system. Phase diagram is obtained as a function of the electron density and the super-exchange interaction using a Monte Carlo minimization. At low super-exchange interaction energy phase transition between electron-full ferromagnetic distorted and electron-empty anti-ferromagnetic undistorted phases occurs. In this case all electrons and lattice distortions were found within the ferromagnetic domain. For high super-exchange interaction energy, phase transition between two site distorted periodic arrangement of independent magnetic polarons ordered anti-ferromagnetically and the electron-empty anti-ferromagnetic undistorted phase was found. For this high interaction energy, Wigner crystallization, lattice distortion and charge distribution inside two-site polarons were obtained.

  12. Double and super-exchange model in one-dimensional systems

    International Nuclear Information System (INIS)

    Vallejo, E.; Navarro, O.; Avignon, M.

    2010-01-01

    We present an analytical and numerical study of the competition between double and super-exchange interactions in a one-dimensional model. For low super-exchange interaction energy we find phase separation between ferromagnetic and anti-ferromagnetic phases. When the super-exchange interaction energy gets larger, the conduction electrons are self-trapped within separate small magnetic polarons. These magnetic polarons contain a single electron inside two or three sites depending on the conduction electron density and form a Wigner crystallization. A new phase separation is found between these small polarons and the anti-ferromagnetic phase. Spin-glass behavior is obtained consistent with experimental results of the nickelate one-dimensional compound Y 2-x Ca x BaNiO 5 .

  13. Large-amplitude superexchange of high-spin fermions in optical lattices

    International Nuclear Information System (INIS)

    Jürgensen, Ole; Heinze, Jannes; Lühmann, Dirk-Sören

    2013-01-01

    We show that fermionic high-spin systems with spin-changing collisions allow one to monitor superexchange processes in optical superlattices with large amplitudes and strong spin fluctuations. By investigating the non-equilibrium dynamics, we find a superexchange dominated regime at weak interactions. The underlying mechanism is driven by an emerging tunneling-energy gap in shallow few-well potentials. As a consequence, the interaction-energy gap that is expected to occur only for strong interactions in deep lattices is re-established. By tuning the optical lattice depth, a crossover between two regimes with negligible particle number fluctuations is found: firstly, the common regime with vanishing spin-fluctuations in deep lattices and, secondly, a novel regime with strong spin fluctuations in shallow lattices. We discuss the possible experimental realization with ultracold 40 K atoms and observable quantities in double wells and two-dimensional plaquettes. (paper)

  14. Superexchange-mediated magnetization dynamics with ultracold alkaline-earth atoms in an optical lattice

    International Nuclear Information System (INIS)

    Zhu Shaobing; Qian Jun; Wang Yuzhu

    2017-01-01

    Superexchange and inter-orbital spin-exchange interactions are key ingredients for understanding (orbital) quantum magnetism in strongly correlated systems and have been realized in ultracold atomic gases. Here we study the spin dynamics of ultracold alkaline-earth atoms in an optical lattice when the two exchange interactions coexist. In the superexchange interaction dominating regime, we find that the time-resolved spin imbalance shows a remarkable modulated oscillation, which can be attributed to the interplay between local and nonlocal quantum mechanical exchange mechanisms. Moreover, the filling of the long-lived excited atoms affects the collapse and revival of the magnetization dynamics. These observations can be realized in state-dependent optical lattices combined with the state-of-the-art advances in optical lattice clock spectroscopy. (paper)

  15. Anisotropic Covalency Contributions to Superexchange Pathways in Type One Copper Active Sites

    Science.gov (United States)

    2015-01-01

    Type one (T1) Cu sites deliver electrons to catalytic Cu active sites: the mononuclear type two (T2) Cu site in nitrite reductases (NiRs) and the trinuclear Cu cluster in the multicopper oxidases (MCOs). The T1 Cu and the remote catalytic sites are connected via a Cys-His intramolecular electron-transfer (ET) bridge, which contains two potential ET pathways: P1 through the protein backbone and P2 through the H-bond between the Cys and the His. The high covalency of the T1 Cu–S(Cys) bond is shown here to activate the T1 Cu site for hole superexchange via occupied valence orbitals of the bridge. This covalency-activated electronic coupling (HDA) facilitates long-range ET through both pathways. These pathways can be selectively activated depending on the geometric and electronic structure of the T1 Cu site and thus the anisotropic covalency of the T1 Cu–S(Cys) bond. In NiRs, blue (π-type) T1 sites utilize P1 and green (σ-type) T1 sites utilize P2, with P2 being more efficient. Comparing the MCOs to NiRs, the second-sphere environment changes the conformation of the Cys-His pathway, which selectively activates HDA for superexchange by blue π sites for efficient turnover in catalysis. These studies show that a given protein bridge, here Cys-His, provides different superexchange pathways and electronic couplings depending on the anisotropic covalencies of the donor and acceptor metal sites. PMID:25310460

  16. Phase coupling in the cardiorespiratory interaction.

    Science.gov (United States)

    Bahraminasab, A; Kenwright, D; Stefanovska, A; Ghasemi, F; McClintock, P V E

    2008-01-01

    Markovian analysis is applied to derive nonlinear stochastic equations for the reconstruction of heart rate and respiration rate variability data. A model of their 'phase' interactions is obtained for the first time, thereby gaining new insights into the strength and direction of the cardiorespiratory phase coupling. The reconstructed model can reproduce synchronisation phenomena between the cardiac and the respiratory systems, including switches in synchronisation ratio. The technique is equally applicable to the extraction of the multi-dimensional couplings between many interacting subsystems.

  17. Vehicle systems: coupled and interactive dynamics analysis

    Science.gov (United States)

    Vantsevich, Vladimir V.

    2014-11-01

    This article formulates a new direction in vehicle dynamics, described as coupled and interactive vehicle system dynamics. Formalised procedures and analysis of case studies are presented. An analytical consideration, which explains the physics of coupled system dynamics and its consequences for dynamics of a vehicle, is given for several sets of systems including: (i) driveline and suspension of a 6×6 truck, (ii) a brake mechanism and a limited slip differential of a drive axle and (iii) a 4×4 vehicle steering system and driveline system. The article introduces a formal procedure to turn coupled system dynamics into interactive dynamics of systems. A new research direction in interactive dynamics of an active steering and a hybrid-electric power transmitting unit is presented and analysed to control power distribution between the drive axles of a 4×4 vehicle. A control strategy integrates energy efficiency and lateral dynamics by decoupling dynamics of the two systems thus forming their interactive dynamics.

  18. Perturbation theory with respect to intercenter electron exchange and superexchange with degeneracy

    International Nuclear Information System (INIS)

    Orlenko, E.V.; Rumyantsev, A.A.

    1990-01-01

    The corrections to the energy and wave functions of a multielectron system of interacting atoms are calculated in a general analytic form by taking into account degeneracy of the states in accordance with the Young schemes. The rule for writing down the perturbation operator in such systems is formulated in the case when the ground and excited state vectors are antisymmetrized with respect to interchange of electrons between the centers. A secular equation of the theory is derived by applying perturbation theory, one of the parameters of which is the degree of overlap of the wave functions. Some concrete examples of interatomic interactions of an unpaired nature which are due to exchange and superexchange effects are considered

  19. Magnetic impurity coupled to interacting conduction electrons

    International Nuclear Information System (INIS)

    Schork, T.

    1996-01-01

    We consider a magnetic impurity which interacts by hybridization with a system of weakly correlated electrons and determine the energy of the ground state by means of a 1/N f expansion. The correlations among the conduction electrons are described by a Hubbard Hamiltonian and are treated to the lowest order in the interaction strength. We find that their effect on the Kondo temperature, T K , in the Kondo limit is twofold: first, the position of the impurity level is shifted due to the reduction of charge fluctuations, which reduces T K . Secondly, the bare Kondo exchange coupling is enhanced as spin fluctuations are enlarged. In total, T K increases. Both corrections require intermediate states beyond the standard Varma-Yafet ansatz. This shows that the Hubbard interaction does not just provide quasiparticles, which hybridize with the impurity, but also renormalizes the Kondo coupling. copyright 1996 The American Physical Society

  20. Interaction function of coupled bursting neurons

    International Nuclear Information System (INIS)

    Shi Xia; Zhang Jiadong

    2016-01-01

    The interaction functions of electrically coupled Hindmarsh–Rose (HR) neurons for different firing patterns are investigated in this paper. By applying the phase reduction technique, the phase response curve (PRC) of the spiking neuron and burst phase response curve (BPRC) of the bursting neuron are derived. Then the interaction function of two coupled neurons can be calculated numerically according to the PRC (or BPRC) and the voltage time course of the neurons. Results show that the BPRC is more and more complicated with the increase of the spike number within a burst, and the curve of the interaction function oscillates more and more frequently with it. However, two certain things are unchanged: ϕ = 0, which corresponds to the in-phase synchronization state, is always the stable equilibrium, while the anti-phase synchronization state with ϕ = 0.5 is an unstable equilibrium. (paper)

  1. Casimir Interaction from Magnetically Coupled Eddy Currents

    Science.gov (United States)

    Intravaia, Francesco; Henkel, Carsten

    2009-09-01

    We study the quantum and thermal fluctuations of eddy (Foucault) currents in thick metallic plates. A Casimir interaction between two plates arises from the coupling via quasistatic magnetic fields. As a function of distance, the relevant eddy current modes cross over from a quantum to a thermal regime. These modes alone reproduce previously discussed thermal anomalies of the electromagnetic Casimir interaction between good conductors. In particular, they provide a physical picture for the Casimir entropy whose nonzero value at zero temperature arises from a correlated, glassy state.

  2. Information flow between weakly interacting lattices of coupled maps

    Energy Technology Data Exchange (ETDEWEB)

    Dobyns, York [PEAR, Princeton University, Princeton, NJ 08544-5263 (United States); Atmanspacher, Harald [Institut fuer Grenzgebiete der Psychologie und Psychohygiene, Wilhelmstr. 3a, 79098 Freiburg (Germany)]. E-mail: haa@igpp.de

    2006-05-15

    Weakly interacting lattices of coupled maps can be modeled as ordinary coupled map lattices separated from each other by boundary regions with small coupling parameters. We demonstrate that such weakly interacting lattices can nevertheless have unexpected and striking effects on each other. Under specific conditions, particular stability properties of the lattices are significantly influenced by their weak mutual interaction. This observation is tantamount to an efficacious information flow across the boundary.

  3. Information flow between weakly interacting lattices of coupled maps

    International Nuclear Information System (INIS)

    Dobyns, York; Atmanspacher, Harald

    2006-01-01

    Weakly interacting lattices of coupled maps can be modeled as ordinary coupled map lattices separated from each other by boundary regions with small coupling parameters. We demonstrate that such weakly interacting lattices can nevertheless have unexpected and striking effects on each other. Under specific conditions, particular stability properties of the lattices are significantly influenced by their weak mutual interaction. This observation is tantamount to an efficacious information flow across the boundary

  4. Effective interactions and coupling schemes in nuclei

    International Nuclear Information System (INIS)

    Talmi, I.

    1994-01-01

    Eigenstates of the shell model are obtained by diagonalization of the Hamiltonian submatrix defined by a given shell model subspace. Matrix elements of the effective nuclear interaction can be determined from experiment in a consistent way. This approach was introduced in 1956 with the 38 Cl- 40 K spectra, has been applied in many cases and its latest success is in the s, d shell. This way, general features of the effective interaction have been determined. The T=1 interaction is diagonal in the seniority scheme as clearly demonstrated in proton 1g 9/2 n and 1h 11/2 n configurations and in the description of semimagic nuclei by generalized seniority. Apart from a strong and attractive pairing term, T=1 interactions are repulsive on the average. The T=0 interaction is attractive and is the origin of the central potential well in which nucleons are bound. It breaks seniority in a major way leading to deformed nuclei and rotational spectra. Such an interaction may be approximated by a quadrupole-quadrupole interaction which is the basis of the interacting boson model. Identical nucleons with pairing and quadrupole interactions cannot be models of actual nuclei. Symmetry properties of states with maximum T are very different from those of ground states of actual nuclei. The T=1 interaction between identical nucleons cannot be approximated by pairing and quadrupole interactions. The rich variety of nuclear spectra is due to the competition between seniority conserving T=1 interactions and the T=0 quadrupole interaction between protons and neutrons. (orig.)

  5. Coupling functions: Universal insights into dynamical interaction mechanisms

    Science.gov (United States)

    Stankovski, Tomislav; Pereira, Tiago; McClintock, Peter V. E.; Stefanovska, Aneta

    2017-10-01

    The dynamical systems found in nature are rarely isolated. Instead they interact and influence each other. The coupling functions that connect them contain detailed information about the functional mechanisms underlying the interactions and prescribe the physical rule specifying how an interaction occurs. A coherent and comprehensive review is presented encompassing the rapid progress made recently in the analysis, understanding, and applications of coupling functions. The basic concepts and characteristics of coupling functions are presented through demonstrative examples of different domains, revealing the mechanisms and emphasizing their multivariate nature. The theory of coupling functions is discussed through gradually increasing complexity from strong and weak interactions to globally coupled systems and networks. A variety of methods that have been developed for the detection and reconstruction of coupling functions from measured data is described. These methods are based on different statistical techniques for dynamical inference. Stemming from physics, such methods are being applied in diverse areas of science and technology, including chemistry, biology, physiology, neuroscience, social sciences, mechanics, and secure communications. This breadth of application illustrates the universality of coupling functions for studying the interaction mechanisms of coupled dynamical systems.

  6. Chimera states in nonlocally coupled phase oscillators with biharmonic interaction

    Science.gov (United States)

    Cheng, Hongyan; Dai, Qionglin; Wu, Nianping; Feng, Yuee; Li, Haihong; Yang, Junzhong

    2018-03-01

    Chimera states, which consist of coexisting domains of coherent and incoherent parts, have been observed in a variety of systems. Most of previous works on chimera states have taken into account specific form of interaction between oscillators, for example, sinusoidal coupling or diffusive coupling. Here, we investigate chimera dynamics in nonlocally coupled phase oscillators with biharmonic interaction. We find novel chimera states with features such as that oscillators in the same coherent cluster may split into two groups with a phase difference around π/2 and that oscillators in adjacent coherent clusters may have a phase difference close to π/2. The different impacts of the coupling ranges in the first and the second harmonic interactions on chimera dynamics are investigated based on the synchronous dynamics in globally coupled phase oscillators. Our study suggests a new direction in the field of chimera dynamics.

  7. Interaction Patterns in Couples with a Depressed Partner.

    Science.gov (United States)

    Hautzinger, Martin

    Recently, research has been conducted using an interactional understanding of depression, which views depression as a disorder exacerbated by a pathogenic social system. The interaction between intimate social partners seems especially relevant. Couples (N=26) participated in a study of depressed out-patients and their spouses and a matched…

  8. Double Super-Exchange in Silicon Quantum Dots Connected by Short-Bridged Networks

    Science.gov (United States)

    Li, Huashan; Wu, Zhigang; Lusk, Mark

    2013-03-01

    Silicon quantum dots (QDs) with diameters in the range of 1-2 nm are attractive for photovoltaic applications. They absorb photons more readily, transport excitons with greater efficiency, and show greater promise in multiple-exciton generation and hot carrier collection paradigms. However, their high excitonic binding energy makes it difficult to dissociate excitons into separate charge carriers. One possible remedy is to create dot assemblies in which a second material creates a Type-II heterojunction with the dot so that exciton dissociation occurs locally. This talk will focus on such a Type-II heterojunction paradigm in which QDs are connected via covalently bonded, short-bridge molecules. For such interpenetrating networks of dots and molecules, our first principles computational investigation shows that it is possible to rapidly and efficiently separate electrons to QDs and holes to bridge units. The bridge network serves as an efficient mediator of electron superexchange between QDs while the dots themselves play the complimentary role of efficient hole superexchange mediators. Dissociation, photoluminescence and carrier transport rates will be presented for bridge networks of silicon QDs that exhibit such double superexchange. This material is based upon work supported by the Renewable Energy Materials Research Science and Engineering Center (REMRSEC) under Grant No. DMR-0820518 and Golden Energy Computing Organization (GECO).

  9. Directional interacting whispering-gallery modes in coupled dielectric microdisks

    International Nuclear Information System (INIS)

    Ryu, Jung-Wan; Lee, Soo-Young; Kim, Chil-Min; Park, Young-Jai

    2006-01-01

    We study the optical interaction in a coupled dielectric microdisks by investigating the splitting of resonance positions of interacting whispering-gallery modes (WGM's) and their pattern change, depending on the distance between the microdisks. It is shown that the interaction between the WGM's with odd parity about the y axis becomes appreciable at a distance less than a wavelength and causes directional emissions of the resulting interacting WGM's. The directionality of the interacting WGM's can be understood in terms of an effective boundary deformation in ray dynamical analysis. We also discuss the oscillation of the splitting when the distance is greater than a wavelength

  10. Exciton-plasmon coupling interactions: from principle to applications

    Science.gov (United States)

    Cao, En; Lin, Weihua; Sun, Mengtao; Liang, Wenjie; Song, Yuzhi

    2018-01-01

    The interaction of exciton-plasmon coupling and the conversion of exciton-plasmon-photon have been widely investigated experimentally and theoretically. In this review, we introduce the exciton-plasmon interaction from basic principle to applications. There are two kinds of exciton-plasmon coupling, which demonstrate different optical properties. The strong exciton-plasmon coupling results in two new mixed states of light and matter separated energetically by a Rabi splitting that exhibits a characteristic anticrossing behavior of the exciton-LSP energy tuning. Compared to strong coupling, such as surface-enhanced Raman scattering, surface plasmon (SP)-enhanced absorption, enhanced fluorescence, or fluorescence quenching, there is no perturbation between wave functions; the interaction here is called the weak coupling. SP resonance (SPR) arises from the collective oscillation induced by the electromagnetic field of light and can be used for investigating the interaction between light and matter beyond the diffraction limit. The study on the interaction between SPR and exaction has drawn wide attention since its discovery not only due to its contribution in deepening and broadening the understanding of SPR but also its contribution to its application in light-emitting diodes, solar cells, low threshold laser, biomedical detection, quantum information processing, and so on.

  11. Identification of coupling direction: Application to cardiorespiratory interaction

    Science.gov (United States)

    Rosenblum, Michael G.; Cimponeriu, Laura; Bezerianos, Anastasios; Patzak, Andreas; Mrowka, Ralf

    2002-04-01

    We consider the problem of experimental detection of directionality of weak coupling between two self-sustained oscillators from bivariate data. We further develop the method introduced by Rosenblum and Pikovsky [Phys. Rev. E 64, 045202 (2001)], suggesting an alternative approach. Next, we consider another framework for identification of directionality, based on the idea of mutual predictability. Our algorithms provide directionality index that shows whether the coupling between the oscillators is unidirectional or bidirectional, and quantifies the asymmetry of bidirectional coupling. We demonstrate the efficiency of three different algorithms in determination of directionality index from short and noisy data. These techniques are then applied to analysis of cardiorespiratory interaction in healthy infants. The results reveal that the direction of coupling between cardiovascular and respiratory systems varies with the age within the first 6 months of life. We find a tendency to change from nearly symmetric bidirectional interaction to nearly unidirectional one (from respiration to the cardiovascular system).

  12. Chaos in generically coupled phase oscillator networks with nonpairwise interactions.

    Science.gov (United States)

    Bick, Christian; Ashwin, Peter; Rodrigues, Ana

    2016-09-01

    The Kuramoto-Sakaguchi system of coupled phase oscillators, where interaction between oscillators is determined by a single harmonic of phase differences of pairs of oscillators, has very simple emergent dynamics in the case of identical oscillators that are globally coupled: there is a variational structure that means the only attractors are full synchrony (in-phase) or splay phase (rotating wave/full asynchrony) oscillations and the bifurcation between these states is highly degenerate. Here we show that nonpairwise coupling-including three and four-way interactions of the oscillator phases-that appears generically at the next order in normal-form based calculations can give rise to complex emergent dynamics in symmetric phase oscillator networks. In particular, we show that chaos can appear in the smallest possible dimension of four coupled phase oscillators for a range of parameter values.

  13. Exchange Coupling Interactions from the Density Matrix Renormalization Group and N-Electron Valence Perturbation Theory: Application to a Biomimetic Mixed-Valence Manganese Complex.

    Science.gov (United States)

    Roemelt, Michael; Krewald, Vera; Pantazis, Dimitrios A

    2018-01-09

    The accurate description of magnetic level energetics in oligonuclear exchange-coupled transition-metal complexes remains a formidable challenge for quantum chemistry. The density matrix renormalization group (DMRG) brings such systems for the first time easily within reach of multireference wave function methods by enabling the use of unprecedentedly large active spaces. But does this guarantee systematic improvement in predictive ability and, if so, under which conditions? We identify operational parameters in the use of DMRG using as a test system an experimentally characterized mixed-valence bis-μ-oxo/μ-acetato Mn(III,IV) dimer, a model for the oxygen-evolving complex of photosystem II. A complete active space of all metal 3d and bridge 2p orbitals proved to be the smallest meaningful starting point; this is readily accessible with DMRG and greatly improves on the unrealistic metal-only configuration interaction or complete active space self-consistent field (CASSCF) values. Orbital optimization is critical for stabilizing the antiferromagnetic state, while a state-averaged approach over all spin states involved is required to avoid artificial deviations from isotropic behavior that are associated with state-specific calculations. Selective inclusion of localized orbital subspaces enables probing the relative contributions of different ligands and distinct superexchange pathways. Overall, however, full-valence DMRG-CASSCF calculations fall short of providing a quantitative description of the exchange coupling owing to insufficient recovery of dynamic correlation. Quantitatively accurate results can be achieved through a DMRG implementation of second order N-electron valence perturbation theory (NEVPT2) in conjunction with a full-valence metal and ligand active space. Perspectives for future applications of DMRG-CASSCF/NEVPT2 to exchange coupling in oligonuclear clusters are discussed.

  14. Quantitative heartbeat coupling measures in human-horse interaction.

    Science.gov (United States)

    Lanata, Antonio; Guidi, Andrea; Valenza, Gaetano; Baragli, Paolo; Scilingo, Enzo Pasquale

    2016-08-01

    We present a study focused on a quantitative estimation of a human-horse dynamic interaction. A set of measures based on magnitude and phase coupling between heartbeat dynamics of both humans and horses in three different conditions is reported: no interaction, visual/olfactory interaction and grooming. Specifically, Magnitude Squared Coherence (MSC), Mean Phase Coherence (MPC) and Dynamic Time Warping (DTW) have been used as estimators of the amount of coupling between human and horse through the analysis of their heart rate variability (HRV) time series in a group of eleven human subjects, and one horse. The rationale behind this study is that the interaction of two complex biological systems go towards a coupling process whose dynamical evolution is modulated by the kind and time duration of the interaction itself. We achieved a congruent and consistent statistical significant difference for all of the three indices. Moreover, a Nearest Mean Classifier was able to recognize the three classes of interaction with an accuracy greater than 70%. Although preliminary, these encouraging results allow a discrimination of three distinct phases in a real human-animal interaction opening to the characterization of the empirically proven relationship between human and horse.

  15. Chaos in generically coupled phase oscillator networks with nonpairwise interactions

    Energy Technology Data Exchange (ETDEWEB)

    Bick, Christian; Ashwin, Peter; Rodrigues, Ana [Centre for Systems, Dynamics and Control and Department of Mathematics, University of Exeter, Exeter EX4 4QF (United Kingdom)

    2016-09-15

    The Kuramoto–Sakaguchi system of coupled phase oscillators, where interaction between oscillators is determined by a single harmonic of phase differences of pairs of oscillators, has very simple emergent dynamics in the case of identical oscillators that are globally coupled: there is a variational structure that means the only attractors are full synchrony (in-phase) or splay phase (rotating wave/full asynchrony) oscillations and the bifurcation between these states is highly degenerate. Here we show that nonpairwise coupling—including three and four-way interactions of the oscillator phases—that appears generically at the next order in normal-form based calculations can give rise to complex emergent dynamics in symmetric phase oscillator networks. In particular, we show that chaos can appear in the smallest possible dimension of four coupled phase oscillators for a range of parameter values.

  16. Hydrodynamic interaction induced spontaneous rotation of coupled active filaments.

    Science.gov (United States)

    Jiang, Huijun; Hou, Zhonghuai

    2014-12-14

    We investigate the coupled dynamics of active filaments with long range hydrodynamic interactions (HI). Remarkably, we find that filaments can rotate spontaneously under the same conditions in which a single filament alone can only move in translation. Detailed analysis reveals that the emergence of coupled rotation originates from an asymmetric flow field associated with HI which breaks the symmetry of translational motion when filaments approach. The breaking is then further stabilized by HI to form self-sustained coupled rotation. Intensive simulations show that coupled rotation forms easily when one filament tends to collide with the front-half of the other. For head-to-tail approaching, we observe another interesting HI-induced coupled motion, where filaments move together in the form of one following the other. Moreover, the radius of coupled rotation increases exponentially as the rigidity of the filament increases, which suggests that HI are also important for the alignment of rigid-rod-like filaments which has been assumed to be solely a consequence of direct collisions.

  17. Tunneling of coupled methyl quantum rotors in 4-methylpyridine: Single rotor potential versus coupling interaction

    Science.gov (United States)

    Khazaei, Somayeh; Sebastiani, Daniel

    2017-11-01

    We study the influence of rotational coupling between a pair of methyl rotators on the tunneling spectrum in condensed phase. Two interacting adjacent methyl groups are simulated within a coupled-pair model composed of static rotational potential created by the chemical environment and the interaction potential between two methyl groups. We solve the two-dimensional time-independent Schrödinger equation analytically by expanding the wave functions on the basis set of two independent free-rotor functions. We investigate three scenarios which differ with respect to the relative strength of single-rotor and coupling potential. For each scenario, we illustrate the dependence of the energy level scheme on the coupling strength. It is found that the main determinant of splitting energy levels tends to be a function of the ratio of strengths of coupling and single-rotor potential. The tunnel splitting caused by coupling is maximized for the coupled rotors in which their total hindering potential is relatively shallow. Such a weakly hindered methyl rotational potential is predicted for 4-methylpyridine at low temperature. The experimental observation of multiple tunneling peaks arising from a single type of methyl group in 4-methylpyridine in the inelastic neutron scattering spectrum is widely attributed to the rotor-rotor coupling. In this regard, using a set of first-principles calculations combined with the nudged elastic band method, we investigate the rotational potential energy surface (PES) of the coaxial pairs of rotors in 4-methylpyridine. A Numerov-type method is used to numerically solve the two-dimensional time-independent Schrödinger equation for the calculated 2D-density functional theory profile. Our computed energy levels reproduce the observed tunneling transitions well. Moreover, the calculated density distribution of the three methyl protons resembles the experimental nuclear densities obtained from the Fourier difference method. By mapping the

  18. Strong-coupling interaction in high-Tc superconductors

    International Nuclear Information System (INIS)

    Ray, D.K.

    1991-01-01

    Extensive experimental and theoretical work have been done to understand the mechanisms of superconductivity. Until 1986 when Bednorz and Muller discovered superconductivity in the copper oxide perovskite, the principal mechanism was found to be electron-phonon interaction and the characteristics of superconductivity vary depending on the strength of the electron-phonon interaction and the electronic structure. The essential characteristic of these conventional superconductors could be divided into two groups: wide band metals with low density of states N(E F ) at the Fermi energy E F and a rather weak electron-phonon coupling V obeying the universal characteristics of the BCS theory and narrow d band metals, compounds, and alloys with high values of N(E F ), electron-phonon coupling V and non negligible Coulomb interaction between the electrons. In this paper a short summary and the important results of these theories are discussed. The inherent limitations of these theories based on electron-phonon interaction will be discussed. The authors indicate the major characteristics of the new superconductors. These characteristics are difficult to explain on the basis of either the conventional electron-phonon theory or theories based on magnetic interactions alone

  19. Interaction of solitons with a string of coupled quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Vijendra, E-mail: vsmedphysics@gmail.com; Swami, O. P., E-mail: omg1789@gmail.com; Nagar, A. K., E-mail: ajaya.nagar@gmail.com [Department of Physics, Govt. Dungar College, Bikaner, Rajasthan 334001 (India); Taneja, S., E-mail: sachintaneja9@gmail.com [Department of Radiotherapy, CHAF Bangalore, Karnataka 560007 (India)

    2016-05-06

    In this paper, we develop a theory for discrete solitons interaction with a string of coupled quantum dots in view of the local field effects. Discrete nonlinear Schrodinger (DNLS) equations are used to describe the dynamics of the string. Numerical calculations are carried out and results are analyzed with the help of matlab software. With the help of numerical solutions we demonstrate that in the quantum dots string, Rabi oscillations (RO) are self trapped into stable bright Rabi solitons. The Rabi oscillations in different types of nanostructures have potential applications to the elements of quantum logic and quantum memory.

  20. Role of spin-orbit coupling in the Kugel-Khomskii model on the honeycomb lattice

    Science.gov (United States)

    Koga, Akihisa; Nakauchi, Shiryu; Nasu, Joji

    2018-03-01

    We study the effective spin-orbital model for honeycomb-layered transition metal compounds, applying the second-order perturbation theory to the three-orbital Hubbard model with the anisotropic hoppings. This model is reduced to the Kitaev model in the strong spin-orbit coupling limit. Combining the cluster mean-field approximations with the exact diagonalization, we treat the Kugel-Khomskii type superexchange interaction and spin-orbit coupling on an equal footing to discuss ground-state properties. We find that a zigzag ordered state is realized in the model within nearest-neighbor interactions. We clarify how the ordered state competes with the nonmagnetic state, which is adiabatically connected to the quantum spin liquid state realized in a strong spin-orbit coupling limit. Thermodynamic properties are also addressed. The present paper should provide another route to account for the Kitaev-based magnetic properties in candidate materials.

  1. Inflationary magnetogenesis, derivative couplings and relativistic Van der Waals interactions

    CERN Document Server

    Giovannini, Massimo

    2015-01-01

    When the gauge fields have derivative couplings to scalars, like in the case of the relativistic theory of Van der Waals (or Casimir-Polder) interactions, conformal invariance is broken but the magnetic and electric susceptibilities are not bound to coincide. We analyze the formation of large-scale magnetic fields in slow-roll inflation and find that they are generated at the level of a few hundredths of a nG and over typical length scales between few Mpc and $100$ Mpc. Using a new time parametrization that reduces to conformal time but only for coincident susceptibilities, the gauge action is quantized while the evolution equations of the corresponding mode functions are more easily solvable. The power spectra depend on the normalized rates of variation of the two susceptibilities (or of the corresponding gauge couplings) and on the absolute value of their ratio at the beginning of inflation. We pin down explicit regions in the parameter space where all the physical requirements (i.e. the backreaction constr...

  2. Vortex coupling in trailing vortex-wing interactions

    Science.gov (United States)

    Chen, C.; Wang, Z.; Gursul, I.

    2018-03-01

    The interaction of trailing vortices of an upstream wing with rigid and flexible downstream wings has been investigated experimentally in a wind tunnel, using particle image velocimetry, hot-wire, force, and deformation measurements. Counter-rotating upstream vortices exhibit increased meandering when they are close to the tip of the downstream wing. The upstream vortex forms a pair with the vortex shed from the downstream wing and then exhibits large displacements around the wing tip. This coupled motion of the pair has been found to cause large lift fluctuations on the downstream wing. The meandering of the vortex pair occurs at the natural meandering frequency of the isolated vortex, with a low Strouhal number, and is not affected by the frequency of the large-amplitude wing oscillations if the downstream wing is flexible. The displacement of the leading vortex is larger than that of the trailing vortex; however, it causes highly correlated variations of the core radius, core vorticity, and circulation of the trailing vortex with the coupled meandering motion. In contrast, co-rotating vortices do not exhibit any increased meandering.

  3. Tunable coupling and ultrastrong interaction in circuit quantum electrodynamics

    International Nuclear Information System (INIS)

    Baust, Alexander Theodor

    2015-01-01

    For future quantum information and quantum simulation architectures with superconducting circuits, a profound understanding of the coupling mechanisms between the individual building blocks is essential. In our work, we investigate galvanically coupled qubit-resonator systems, demonstrate the phenomenon of ultrastrong coupling and realize qubit mediated tunable and switchable coupling between two frequency-degenerate coplanar microwave resonators.

  4. Effective interactions in strongly-coupled quantum systems

    International Nuclear Information System (INIS)

    Chen, J.M.C.

    1986-01-01

    In this thesis, they study the role of effective interactions in strongly-coupled Fermi systems where the short-range correlations introduce difficulties requiring special treatment. The correlated basis function method provides the means to incorporate the short-range correlations and generate the matrix elements of the Hamiltonian and identity operators in a nonorthogonal basis of states which are so important to their studies. In the first half of the thesis, the particle-hole channel is examined to elucidate the effects of collective excitations. Proceeding from a least-action principle, a generalization of the random-phase approximation is developed capable of describing such strongly-interacting Fermi systems as nuclei, nuclear matter, neutron-star matter, and liquid 3 He. A linear response of dynamically correlated system to a weak external perturbation is also derived based on the same framework. In the second half of the thesis, the particle-particle channel is examined to elucidate the effects of pairing in nuclear and neutron-star matter

  5. Magnetic Interaction between Surface-Engineered Rare-Earth Atomic Spins

    Directory of Open Access Journals (Sweden)

    Chiung-Yuan Lin

    2012-06-01

    Full Text Available We report the ab-initio study of rare-earth adatoms (Gd on an insulating surface. This surface is of interest because of previous studies by scanning tunneling microscopy showing spin excitations of transition-metal adatoms. The present work is the first study of rare-earth spin-coupled adatoms, as well as the geometry effect of spin coupling and the underlying mechanism of ferromagnetic coupling. The exchange coupling between Gd atoms on the surface is calculated to be antiferromagnetic in a linear geometry and ferromagnetic in a diagonal geometry. We also find that the Gd dimers in these two geometries are similar to the nearest-neighbor and the next-nearest-neighbor Gd atoms in GdN bulk. We analyze how much direct exchange, superexchange, and Ruderman-Kittel-Kasuya-Yosida interactions contribute to the exchange coupling for both geometries by additional first-principles calculations of related model systems.

  6. Vibrational Interaction of Two Rotors with Friction Coupling

    Directory of Open Access Journals (Sweden)

    H. Larsson

    2016-01-01

    Full Text Available A lumped parameter model is presented for studying the dynamic interaction between two disks in relative rotational motion and in friction contact. The contact elastic and dissipative characteristics are represented by equivalent stiffness and damping coefficient in the axial as well as torsional direction. The formulation accounts for the coupling between the axial and angular motions by viewing the contact normal force a result of axial behavior of the system. The model is used to investigate stick-slip behavior of a two-disk friction system. In this effort the friction coefficient is represented as an exponentially decaying function of relative angular velocity, varying from its static value at zero relative velocity to its kinetic value at very high velocities. This investigation results in the establishment of critical curve defining two-parameter regions: one in which stick-slip occurs and that in which stick-slip does not occur. Moreover, the onset and termination of stick-slip, when it occurs, are related to the highest component frequency in the system. It is found that stick-slip starts at a period nearly equal to that of the highest component frequency and terminates at a period almost three times that of the highest component frequency.

  7. Couplings

    Science.gov (United States)

    Stošić, Dušan; Auroux, Aline

    Basic principles of calorimetry coupled with other techniques are introduced. These methods are used in heterogeneous catalysis for characterization of acidic, basic and red-ox properties of solid catalysts. Estimation of these features is achieved by monitoring the interaction of various probe molecules with the surface of such materials. Overview of gas phase, as well as liquid phase techniques is given. Special attention is devoted to coupled calorimetry-volumetry method. Furthermore, the influence of different experimental parameters on the results of these techniques is discussed, since it is known that they can significantly influence the evaluation of catalytic properties of investigated materials.

  8. Coupled-resonator waveguide perfect transport single-photon by interatomic dipole-dipole interaction

    Science.gov (United States)

    Yan, Guo-an; Lu, Hua; Qiao, Hao-xue; Chen, Ai-xi; Wu, Wan-qing

    2018-06-01

    We theoretically investigate single-photon coherent transport in a one-dimensional coupled-resonator waveguide coupled to two quantum emitters with dipole-dipole interactions. The numerical simulations demonstrate that the transmission spectrum of the photon depends on the two atoms dipole-dipole interactions and the photon-atom couplings. The dipole-dipole interactions may change the dip positions in the spectra and the coupling strength may broaden the frequency band width in the transmission spectrum. We further demonstrate that the typical transmission spectra split into two dips due to the dipole-dipole interactions. This phenomenon may be used to manufacture new quantum waveguide devices.

  9. Magnetosphere-thermosphere coupling: An experiment in interactive modeling

    International Nuclear Information System (INIS)

    Forbes, J.M.; Harel, M.

    1989-01-01

    The Rice convection model (RCM) is utilized to investigate the electrodynamic coupling between the inner magnetosphere and the thermosphere including the effects of EUV- and convection-driven neutral winds under quasi-equilibrium conditions. A unique aspect of the study is that the convection-driven winds are included self-consistently and interactively; that is, a steady state wind parameterization is written analytically in terms of the electrostatic potential, which is in turn included in a closed-loop calculation for the electric potential itself. Simulations are performed from 1,400 UT to 1,600 UT during the CDAW-6 interval on March 22, 1979, when the cross-cap electric potential attains values of order 140-180 kV. During the early phases of the disturbance when the normal shielding from high latitudes breaks down, the neutral winds do not modify appreciably the disturbance electric fields at middle and low latitudes. As the system approaches a quasi-equilibrium state, the neutral winds play a much more significant role. The convection driven component of the neutral wind similarly acts to reduce the southward field in the noon sector, but gives rise to an enhancement in the dusk sector field extending to middle latitudes. The parameterized Pedersen effective winds are of order 300 ms -1 and reflect the familiar two-cell pattern with antisunward flow over the polar cap and return flows in the dawn and dusk sectors. These amplitudes and similarity with the ion drift motions reflect the relatively large contributions to the Pedersen effective winds originating in the upper E region and lower F region of the ionosphere. Possibilities for introducing further sophistication into the wind parameterization are discussed, as well as ramifications of the present study on the possible merging of the RCM with the NCAR TGCM to attain a higher degree of self-consistency and reality in modelling efforts

  10. Microscopic origin of magnetism and magnetic interactions in ferropnictides

    Science.gov (United States)

    Johannes, M. D.; Mazin, I. I.

    2009-06-01

    One year after their initial discovery, two schools of thought have crystallized regarding the electronic structure and magnetic properties of ferropnictide systems. One postulates that these are itinerant weakly correlated metallic systems that become magnetic by virtue of spin-Peierls-type transition due to near nesting between the hole and the electron Fermi-surface pockets. The other argues that these materials are strongly or at least moderately correlated and the electrons are considerably localized and close to a Mott-Hubbard transition, with the local magnetic moments interacting via short-range superexchange. In this Rapid Communication we argue that neither picture is fully correct. The systems are moderately correlated but with correlations driven by Hund’s rule coupling rather than by the on-site Hubbard repulsion. The iron moments are largely local, driven by Hund’s intra-atomic exchange. Superexchange is not operative, and the interactions between the Fe moments are considerably long range and driven mostly by one-electron energies of all occupied states.

  11. α-K2AgF4: Ferromagnetism induced by the weak superexchange of different eg orbitals from the nearest neighbor Ag ions

    Science.gov (United States)

    Zhang, Xiaoli; Zhang, Guoren; Jia, Ting; Zeng, Zhi; Lin, H. Q.

    2016-05-01

    We study the abnormal ferromagnetism in α-K2AgF4, which is very similar to high-TC parent material La2CuO4 in structure. We find out that the electron correlation is very important in determining the insulating property of α-K2AgF4. The Ag(II) 4d9 in the octahedron crystal field has the t2 g 6 eg 3 electron occupation with eg x2-y2 orbital fully occupied and 3z2-r2 orbital partially occupied. The two eg orbitals are very extended indicating both of them are active in superexchange. Using the Hubbard model combined with Nth-order muffin-tin orbital (NMTO) downfolding technique, it is concluded that the exchange interaction between eg 3z2-r2 and x2-y2 from the first nearest neighbor Ag ions leads to the anomalous ferromagnetism in α-K2AgF4.

  12. α-K2AgF4: Ferromagnetism induced by the weak superexchange of different eg orbitals from the nearest neighbor Ag ions

    Directory of Open Access Journals (Sweden)

    Xiaoli Zhang

    2016-05-01

    Full Text Available We study the abnormal ferromagnetism in α-K2AgF4, which is very similar to high-TC parent material La2CuO4 in structure. We find out that the electron correlation is very important in determining the insulating property of α-K2AgF4. The Ag(II 4d9 in the octahedron crystal field has the t 2 g 6 e g 3 electron occupation with eg x2-y2 orbital fully occupied and 3z2-r2 orbital partially occupied. The two eg orbitals are very extended indicating both of them are active in superexchange. Using the Hubbard model combined with Nth-order muffin-tin orbital (NMTO downfolding technique, it is concluded that the exchange interaction between eg 3z2-r2 and x2-y2 from the first nearest neighbor Ag ions leads to the anomalous ferromagnetism in α-K2AgF4.

  13. Co-simulation coupling spectral/finite elements for 3D soil/structure interaction problems

    Science.gov (United States)

    Zuchowski, Loïc; Brun, Michael; De Martin, Florent

    2018-05-01

    The coupling between an implicit finite elements (FE) code and an explicit spectral elements (SE) code has been explored for solving the elastic wave propagation in the case of soil/structure interaction problem. The coupling approach is based on domain decomposition methods in transient dynamics. The spatial coupling at the interface is managed by a standard coupling mortar approach, whereas the time integration is dealt with an hybrid asynchronous time integrator. An external coupling software, handling the interface problem, has been set up in order to couple the FE software Code_Aster with the SE software EFISPEC3D.

  14. Antiferromagnetic coupling of TbPc2 molecules to ultrathin Ni and Co films

    Directory of Open Access Journals (Sweden)

    David Klar

    2013-05-01

    Full Text Available The magnetic and electronic properties of single-molecule magnets are studied by X-ray absorption spectroscopy and X-ray magnetic circular dichroism. We study the magnetic coupling of ultrathin Co and Ni films that are epitaxially grown onto a Cu(100 substrate, to an in situ deposited submonolayer of TbPc2 molecules. Because of the element specificity of the X-ray absorption spectroscopy we are able to individually determine the field dependence of the magnetization of the Tb ions and the Ni or Co film. On both substrates the TbPc2 molecules couple antiferromagnetically to the ferromagnetic films, which is possibly due to a superexchange interaction via the phthalocyanine ligand that contacts the magnetic surface.

  15. Soliton interaction in the coupled mixed derivative nonlinear Schroedinger equations

    International Nuclear Information System (INIS)

    Zhang Haiqiang; Tian Bo; Lue Xing; Li He; Meng Xianghua

    2009-01-01

    The bright one- and two-soliton solutions of the coupled mixed derivative nonlinear Schroedinger equations in birefringent optical fibers are obtained by using the Hirota's bilinear method. The investigation on the collision dynamics of the bright vector solitons shows that there exists complete or partial energy switching in this coupled model. Such parametric energy exchanges can be effectively controlled and quantificationally measured by analyzing the collision dynamics of the bright vector solitons. The influence of two types of nonlinear coefficient parameters on the energy of each vector soliton, is also discussed. Based on the significant energy transfer between the two components of each vector soliton, it is feasible to exploit the future applications in the design of logical gates, fiber directional couplers and quantum information processors.

  16. Time-varying interaction leads to amplitude death in coupled ...

    Indian Academy of Sciences (India)

    2013-09-05

    Sep 5, 2013 ... ety of contexts in physical, biological, and social sciences [1,2]. Several ... have contributed further to the understanding of this effect [18], ..... The network of oscillators with active–passive interaction also show the occurrence.

  17. RKKY coupling in the gadolinium with shielded exchange interaction

    International Nuclear Information System (INIS)

    Aveline, A.

    1973-01-01

    The model of magnetic interation by indirect exchange mechanism (RKKY) is studied. The shielding effect is estimated and exchange integral J(K vector, K' vector) and magnetic interaction energy Jmn(r) analysis is made. The magnetic interaction energy is determinated in two approximations and compared to the Ruderman-Kittel formula. The free electrons model, to conduction electrons, and 4f wave functions, to localized electrons were utilized [pt

  18. Threshold couplings of phase-conjugate mirrors with two interaction regions.

    Science.gov (United States)

    Beli, M; Petrovi, M; Sandfuchs, O; Kaiser, F

    1998-03-01

    Using the grating-action method, we determine the threshold coupling strengths of three generic examples of phase-conjugate mirrors with two interaction regions: the cat conjugator, the mutually incoherent beam coupler, and the interconnected ring mirror.

  19. Strong coupling of two interacting excitons confined in a nanocavity-quantum dot system

    International Nuclear Information System (INIS)

    Cardenas, Paulo C; RodrIguez, Boris A; Quesada, Nicolas; Vinck-Posada, Herbert

    2011-01-01

    We present a study of the strong coupling between radiation and matter, considering a system of two quantum dots, which are in mutual interaction and interact with a single mode of light confined in a semiconductor nanocavity. We take into account dissipative mechanisms such as the escape of the cavity photons, decay of the quantum dot excitons by spontaneous emission, and independent exciton pumping. It is shown that the mutual interaction between the dots can be measured off-resonance only if the strong coupling condition is reached. Using the quantum regression theorem, a reasonable definition of the dynamical coupling regimes is introduced in terms of the complex Rabi frequency. Finally, the emission spectrum for relevant conditions is presented and compared with the above definition, demonstrating that the interaction between the excitons does not affect the strong coupling.

  20. Interaction of chimera states in a multilayered network of nonlocally coupled oscillators

    Science.gov (United States)

    Goremyko, M. V.; Maksimenko, V. A.; Makarov, V. V.; Ghosh, D.; Bera, B.; Dana, S. K.; Hramov, A. E.

    2017-08-01

    The processes of formation and evolution of chimera states in the model of a multilayered network of nonlinear elements with complex coupling topology are studied. A two-layered network of nonlocally intralayer-coupled Kuramoto-Sakaguchi phase oscillators is taken as the object of investigation. Different modes implemented in this system upon variation of the degree of interlayer interaction are demonstrated.

  1. Numerical study of coupled fluid-structure interaction for combustion system

    NARCIS (Netherlands)

    Khatir, Z.; Pozarlik, Artur Krzysztof; Cooper, R.K.; Watterson, J.W.; Kok, Jacobus B.W.

    2007-01-01

    The computation of fluid–structure interaction (FSI) problems requires solving simultaneously the coupled fluid and structure equations. A partitioned approach using a volume spline solution procedure is applied for the coupling of fluid dynamics and structural dynamics codes. For comparative study,

  2. Electronic coupling through natural amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Berstis, Laura; Beckham, Gregg T., E-mail: michael.crowley@nrel.gov, E-mail: gregg.beckham@nrel.gov; Crowley, Michael F., E-mail: michael.crowley@nrel.gov, E-mail: gregg.beckham@nrel.gov [National Renewable Energy Laboratory, National Bioenergy Center, 15013 Denver West Pkwy, Golden, Colorado 80401 (United States)

    2015-12-14

    Myriad scientific domains concern themselves with biological electron transfer (ET) events that span across vast scales of rate and efficiency through a remarkably fine-tuned integration of amino acid (AA) sequences, electronic structure, dynamics, and environment interactions. Within this intricate scheme, many questions persist as to how proteins modulate electron-tunneling properties. To help elucidate these principles, we develop a model set of peptides representing the common α-helix and β-strand motifs including all natural AAs within implicit protein-environment solvation. Using an effective Hamiltonian strategy with density functional theory, we characterize the electronic coupling through these peptides, furthermore considering side-chain dynamics. For both motifs, predictions consistently show that backbone-mediated electronic coupling is distinctly sensitive to AA type (aliphatic, polar, aromatic, negatively charged and positively charged), and to side-chain orientation. The unique properties of these residues may be employed to design activated, deactivated, or switch-like superexchange pathways. Electronic structure calculations and Green’s function analyses indicate that localized shifts in the electron density along the peptide play a role in modulating these pathways, and further substantiate the experimentally observed behavior of proline residues as superbridges. The distinct sensitivities of tunneling pathways to sequence and conformation revealed in this electronic coupling database help improve our fundamental understanding of the broad diversity of ET reactivity and provide guiding principles for peptide design.

  3. Coupled Qubits for Next Generation Quantum Annealing: Novel Interactions

    Science.gov (United States)

    Samach, Gabriel; Weber, Steven; Hover, David; Rosenberg, Danna; Yoder, Jonilyn; Kim, David; Oliver, William D.; Kerman, Andrew J.

    While the first generation of quantum annealers based on Josephson junction technology have been successfully engineered to represent arrays of spins in the quantum transverse-field Ising model, no circuit architecture to date has succeeded in emulating the more complicated non-stoquastic Hamiltonians of interest for next generation quantum annealing. Here, we present our recent results for tunable ZZ- and XX-coupling between high coherence superconducting flux qubits. We discuss the larger architectures these coupled two-qubit building blocks will enable, as well as comment on the limitations of such architectures. This research was funded by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA) and by the Assistant Secretary of Defense for Research & Engineering under Air Force Contract No. FA8721-05-C-0002. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of ODNI, IARPA, or the US Government.

  4. Strongly coupled semiclassical plasma: interaction model and some properties

    International Nuclear Information System (INIS)

    Baimbetov, N.F.; Bekenov, N.A.

    1999-01-01

    In the report a fully ionized strongly coupled hydrogen plasma is considered. The density number is considered within range n=n e =n i ≅(10 21 -2·10 25 )sm -3 , and the temperature domian is T≅(5·10 4 -10 6 ) K. The coupling parameter Γ is defined by Γ=e 2 /αk B T, where k B is the Boltzmann constant and e is electrical charge, α=(3/4πn) 1/3 is the average distance between the particles (Wigner-Seitz radius). The dimensionless density parameter r s =α/α B is given in terms of the Bohr radius α B =ℎ 2 /me 2 ∼0.529·10 - 8 sm. The degeneracy parameter for the electron was defined by the ratio between the thermal energy k B T and the Fermi energy E F :Θ=k B T/E F ∼0.54·r s /Γ. The intermediate temperature-density region, where Γ≥1; Θ≅1; T>13.6 eV is examined. A semiclassical effective potential which account for the short-range, quantum diffraction and symmetry effects of charge carriers screening

  5. Strong Interactive Massive Particles from a Strong Coupled Theory

    DEFF Research Database (Denmark)

    Yu. Khlopov, Maxim; Kouvaris, Christoforos

    2008-01-01

    (-2). These excessive techniparticles are all captured by $^4He$, creating \\emph{techni-O-helium} $tOHe$ ``atoms'', as soon as $^4He$ is formed in Big Bang Nucleosynthesis. The interaction of techni-O-helium with nuclei opens new paths to the creation of heavy nuclei in Big Bang Nucleosynthesis. Due...

  6. Resonance tuning due to Coulomb interaction in strong near-field coupled metamaterials

    International Nuclear Information System (INIS)

    Roy Chowdhury, Dibakar; Xu, Ningning; Zhang, Weili; Singh, Ranjan

    2015-01-01

    Coulomb's law is one of the most fundamental laws of physics that describes the electrostatic interaction between two like or unlike point charges. Here, we experimentally observe a strong effect of Coulomb interaction in tightly coupled terahertz metamaterials where the split-ring resonator dimers in a unit cell are coupled through their near fields across the capacitive split gaps. Using a simple analytical model, we evaluated the Coulomb parameter that switched its sign from negative to positive values indicating the transition in the nature of Coulomb force from being repulsive to attractive depending upon the near field coupling between the split ring resonators. Apart from showing interesting effects in the strong coupling regime between meta-atoms, Coulomb interaction also allows an additional degree of freedom to achieve frequency tunable dynamic metamaterials

  7. Exchange coupling interactions in a Fe6 complex: A theoretical study using density functional theory

    International Nuclear Information System (INIS)

    Cauchy, Thomas; Ruiz, Eliseo; Alvarez, Santiago

    2006-01-01

    Theoretical methods based on density functional theory have been employed to analyze the exchange interactions in an Fe 6 complex. The calculated exchange coupling constants are consistent with an S=5 ground state and agree well with those reported previously for other Fe III polynuclear complexes. Ferromagnetic interactions may appear through exchange pathways formed by two bridging hydroxo or oxo ligands

  8. The Effect of Daily Challenges in Children with Autism on Parents’ Couple Problem-Solving Interactions

    Science.gov (United States)

    Hartley, Sigan L.; Papp, Lauren M.; Blumenstock, Shari; Floyd, Frank; Goetz, Greta L.

    2016-01-01

    The vulnerability-stress-adaptation model guided this examination of the impact of daily fluctuations in the symptoms and co-occurring behavior problems of children with autism spectrum disorder (ASD) on parents’ couple problem-solving interactions in natural settings and as these interactions spontaneously occur. A 14-day daily diary was completed by mothers and fathers in 176 families who had a child with ASD. On each day of the diary, parents separately reported on the child with ASD's daily level of symptoms and co-occurring behavior problems and the topic and level of negative affect in their most meaningful or important daily couple problem-solving interaction. Multilevel modeling was used to account for the within-person, within-couple nested structure of the data. Results indicated that many parents are resilient to experiencing a day with a high level of child ASD symptoms and co-occurring behavior problems and do not report more negative couple problem-solving interactions. However, household income, level of parental broader autism phenotype, and presence of multiple children with special care needs served as vulnerability factors in that they were related to a higher overall rating of negative affect in couple interactions and moderated the impact of reporting a day with a high level of child ASD symptoms and co-occurring behavior problems on next-day ratings of negative couple problem-solving interactions. The magnitude of these effects was small. Understanding mechanisms that support adaptive couple interactions in parents of children with ASD is critical for promoting best outcomes. PMID:27336179

  9. Relationship Quality and Alcohol-Related Social Reinforcement during Couples Interaction.

    Science.gov (United States)

    Fairbairn, Catharine E; Testa, Maria

    2016-01-01

    Individuals who are unhappy in their intimate partnerships are at risk for developing alcohol problems. But little is known about the mechanisms underlying this link. One possibility is that couples with poor relationship quality gain more reinforcement from alcohol in certain contexts-a possibility that has never previously been empirically examined. In the current study, 304 individuals (152 couples) were assigned to receive alcohol (target BAC .08%) or a non-alcoholic beverage. They then engaged in a conflict-resolution interaction with their partners. Videotaped interactions were coded by trained observers. Results revealed a significant interaction between alcohol and relationship quality across multiple measures. Alcohol decreased negative behaviors, decreased negative reciprocity, and enhanced self-reported experience to a greater extent during interactions involving individuals reporting low relationship quality and had comparatively little effect among those reporting high relationship quality. Findings point to a potential mechanism underlying problem drinking among couples with poor relationship quality.

  10. Quantifying interactions between real oscillators with information theory and phase models: Application to cardiorespiratory coupling

    Science.gov (United States)

    Zhu, Yenan; Hsieh, Yee-Hsee; Dhingra, Rishi R.; Dick, Thomas E.; Jacono, Frank J.; Galán, Roberto F.

    2013-02-01

    Interactions between oscillators can be investigated with standard tools of time series analysis. However, these methods are insensitive to the directionality of the coupling, i.e., the asymmetry of the interactions. An elegant alternative was proposed by Rosenblum and collaborators [M. G. Rosenblum, L. Cimponeriu, A. Bezerianos, A. Patzak, and R. Mrowka, Phys. Rev. EPLEEE81063-651X10.1103/PhysRevE.65.041909 65, 041909 (2002); M. G. Rosenblum and A. S. Pikovsky, Phys. Rev. EPLEEE81063-651X10.1103/PhysRevE.64.045202 64, 045202 (2001)] which consists in fitting the empirical phases to a generic model of two weakly coupled phase oscillators. This allows one to obtain the interaction functions defining the coupling and its directionality. A limitation of this approach is that a solution always exists in the least-squares sense, even in the absence of coupling. To preclude spurious results, we propose a three-step protocol: (1) Determine if a statistical dependency exists in the data by evaluating the mutual information of the phases; (2) if so, compute the interaction functions of the oscillators; and (3) validate the empirical oscillator model by comparing the joint probability of the phases obtained from simulating the model with that of the empirical phases. We apply this protocol to a model of two coupled Stuart-Landau oscillators and show that it reliably detects genuine coupling. We also apply this protocol to investigate cardiorespiratory coupling in anesthetized rats. We observe reciprocal coupling between respiration and heartbeat and that the influence of respiration on the heartbeat is generally much stronger than vice versa. In addition, we find that the vagus nerve mediates coupling in both directions.

  11. A facile way to realize exchange coupling interaction in hard/soft magnetic composites

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dongyun, E-mail: lidongyun@cjlu.edu.cn [College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China); Wang, Fan [College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China); Xia, Ailin, E-mail: alxia@126.com [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243032 (China); Zhang, Lijiao [School of Science, Hebei University of Science and Technology, Shijiazhuang 050018 (China); Li, Tingting; Jin, Chuangui; Liu, Xianguo [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243032 (China)

    2016-11-01

    SrFe{sub 12}O{sub 19}/CoFe{sub 2}O{sub 4} and SrFe{sub 12}O{sub 19}/Fe–B hard/soft magnetic composites were obtained by using powders synthesized via a hydrothermal and a molten salt method, respectively. The exchange coupling interaction was found to exist in the composites after a facile grinding according to the results of magnetic hysteresis loops and irreversible sloping recoil loops. It can be found that different grinding time affects their magnetic properties slightly. Our study proves that the conditions of realizing exchange coupling interaction may not be so stringent. - Highlights: • SrM/CFO and SrM/Fe–B with exchange coupling were obtained via a grinding way. • Different grinding time affects their magnetic properties slightly. • The conditions of realizing exchange coupling may not be so stringent.

  12. Strong coupling strategy for fluid-structure interaction problems in supersonic regime via fixed point iteration

    Science.gov (United States)

    Storti, Mario A.; Nigro, Norberto M.; Paz, Rodrigo R.; Dalcín, Lisandro D.

    2009-03-01

    In this paper some results on the convergence of the Gauss-Seidel iteration when solving fluid/structure interaction problems with strong coupling via fixed point iteration are presented. The flow-induced vibration of a flat plate aligned with the flow direction at supersonic Mach number is studied. The precision of different predictor schemes and the influence of the partitioned strong coupling on stability is discussed.

  13. Tetraquark candidate Zc(3900 from coupled-channel scattering - how to extract hadronic interactions? -

    Directory of Open Access Journals (Sweden)

    Ikeda Yoichi

    2018-01-01

    On the basis of the HAL QCD method, the structure of the tetraquark candidate Zc(3900, which was experimentally reported in e+e- collisions, is studied by the s-wave two-meson coupled-channel scattering. The results show that the Zc(3900 is not a conventional resonance but a threshold cusp. A semi-phenomenological analysis with the coupled-channel interaction to the experimentally observed decay mode is also presented to confirm the conclusion.

  14. Pfaffian Solutions and Resonant Interaction Properties of a Coupled BKP Lattice

    International Nuclear Information System (INIS)

    Zhao Hai-Qiong; Yu Guo-Fu

    2014-01-01

    In this paper, we give a coupled lattice equation with the help of Hirota operators, which comes from a special BKP lattice. Two-soliton and three-soliton solutions to the coupled system are constructed. Furthermore, resonant interaction of the two-soliton solution is analyzed in detail. Under some special resonant condition, it is shown that low soliton can propagate faster than high one. Finally, the N-soliton solution is presented in the Pfaffian form. (general)

  15. Investigation of fluid-structure interaction with various types of junction coupling

    Science.gov (United States)

    Ahmadi, A.; Keramat, A.

    2010-10-01

    In this study of water hammer with fluid-structure interaction (FSI) the main aim was the investigation of junction coupling effects. Junction coupling effects were studied in various types of discrete points, such as pumps, valves and branches. The emphasis was placed on an unrestrained pump and branch in the system, and the associated relations were derived for modelling them. Proposed relations were considered as boundary conditions for the numerical modelling which was implemented using the finite element method for the structural equations and the method of characteristics for the hydraulic equations. The results can be used by engineers in finding where junction coupling is significant.

  16. Non abelian Chern-Simons topological coupling from self-interaction

    International Nuclear Information System (INIS)

    Aragone, C.; Stephany, R.J.E.

    1986-01-01

    It is shown that the self-interaction mechanism drives in one step the topologically coupled-Maxwell-second rank antisymmetric tensor system into the Chern-Simons coupled -non abelian- (second rank) antisymmetric tensor action. Only one step is required to saturate the process because the action for the initial Maxwell-antisymmetric tensor system is given in its first-order form. The self-interaction mechanism works both for the original Chapline-Manton form of the action and for the dual form. (Author) [pt

  17. Running coupling in electroweak interactions of leptons from f(R)-gravity with torsion

    International Nuclear Information System (INIS)

    Capozziello, Salvatore; De Laurentis, Mariafelicia; Fabbri, Luca; Vignolo, Stefano

    2012-01-01

    The f(R)-gravitational theory with torsion is considered for one family of leptons; it is found that the torsion tensor gives rise to interactions having the structure of the weak forces, while the intrinsic non-linearity of the f(R) function provides an energy-dependent coupling: in this way, torsional f(R) gravity naturally generates both structure and strength of the electroweak interactions among leptons. This implies that the weak interactions among the lepton fields could be addressed as a geometric effect due to the interactions among spinors induced by the presence of torsion in the most general f(R) gravity. Phenomenological considerations are given. (orig.)

  18. Influence of the Coulomb interaction on the exchange coupling in granular magnets.

    Science.gov (United States)

    Udalov, O G; Beloborodov, I S

    2017-04-20

    We develop a theory of the exchange interaction between ferromagnetic (FM) metallic grains embedded into insulating matrix by taking into account the Coulomb blockade effects. For bulk ferromagnets separated by the insulating layer the exchange interaction strongly depends on the height and thickness of the tunneling barrier created by the insulator. We show that for FM grains embedded into insulating matrix the exchange coupling additionally depends on the dielectric properties of this matrix due to the Coulomb blockade effects. In particular, the FM coupling decreases with decreasing the dielectric permittivity of insulating matrix. We find that the change in the exchange interaction due to the Coulomb blockade effects can be a few tens of percent. Also, we study dependence of the intergrain exchange interaction on the grain size and other parameters of the system.

  19. PDZ domain-mediated interactions of G protein-coupled receptors with postsynaptic density protein 95

    DEFF Research Database (Denmark)

    Møller, Thor C; Wirth, Volker F; Roberts, Nina Ingerslev

    2013-01-01

    G protein-coupled receptors (GPCRs) constitute the largest family of membrane proteins in the human genome. Their signaling is regulated by scaffold proteins containing PDZ domains, but although these interactions are important for GPCR function, they are still poorly understood. We here present...

  20. Coupled radiative gasdynamic interaction and non-equilibrium dissociation for large-scale returned space vehicles

    International Nuclear Information System (INIS)

    Surzhikov, S.

    2012-01-01

    Graphical abstract: It has been shown that different coupled vibrational dissociation models, being applied for solving coupled radiative gasdynamic problems for large size space vehicles, exert noticeable effect on radiative heating of its surface at orbital entry on high altitudes (h ⩾ 70 km). This influence decreases with decreasing the space vehicles sizes. Figure shows translational (solid lines) and vibrational (dashed lines) temperatures in shock layer with (circle markers) and without (triangles markers) radiative-gasdynamic interaction for one trajectory point of entering space vehicle. Highlights: ► Nonequilibrium dissociation processes exert effect on radiation heating of space vehicles (SV). ► The radiation gas dynamic interaction enhances this influence. ► This influence increases with increasing the SV sizes. - Abstract: Radiative aerothermodynamics of large-scale space vehicles is considered for Earth orbital entry at zero angle of attack. Brief description of used radiative gasdynamic model of physically and chemically nonequilibrium, viscous, heat conductive and radiative gas of complex chemical composition is presented. Radiation gasdynamic (RadGD) interaction in high temperature shock layer is studied by means of numerical experiment. It is shown that radiation–gasdynamic coupling for orbital space vehicles of large size is important for high altitude part of entering trajectory. It is demonstrated that the use of different models of coupled vibrational dissociation (CVD) in conditions of RadGD interaction gives rise temperature variation in shock layer and, as a result, leads to significant variation of radiative heating of space vehicle.

  1. The mode coupling theory in the FDR-preserving field theory of interacting Brownian particles

    International Nuclear Information System (INIS)

    Kim, Bongsoo; Kawasaki, Kyozi

    2007-01-01

    We develop a renormalized perturbation theory for the dynamics of interacting Brownian particles, which preserves the fluctuation-dissipation relation order by order. We then show that the resulting one-loop theory gives a closed equation for the density correlation function, which is identical with that in the standard mode coupling theory. (fast track communication)

  2. Strong Coupling Asymptotics for a Singular Schrodinger Operator with an Interaction Supported by an Open Arc

    Czech Academy of Sciences Publication Activity Database

    Exner, Pavel; Pankrashkin, K.

    2014-01-01

    Roč. 39, č. 2 (2014), s. 193-212 ISSN 0360-5302 R&D Projects: GA ČR GAP203/11/0701 Institutional support: RVO:61389005 Keywords : Eigenvalue * Schrödinger operator * singular interaction * strong coupling * 35Q40 * 35P15 * 35J10 Subject RIV: BE - Theoretical Physics Impact factor: 1.013, year: 2014

  3. Tunneling couplings in discrete lattices, single-particle band structure, and eigenstates of interacting atom pairs

    International Nuclear Information System (INIS)

    Piil, Rune; Moelmer, Klaus

    2007-01-01

    By adjusting the tunneling couplings over longer than nearest-neighbor distances, it is possible in discrete lattice models to reproduce the properties of the lowest energy band of a real, continuous periodic potential. We propose to include such terms in problems with interacting particles, and we show that they have significant consequences for scattering and bound states of atom pairs in periodic potentials

  4. Coupling effects of depletion interactions in a three-sphere colloidal system

    International Nuclear Information System (INIS)

    Chen Ze-Shun; Dai Gang; Gao Hai-Xia; Xiao Chang-Ming

    2013-01-01

    In a three-sphere system, the middle sphere is acted upon by two opposite depletion forces from the other two spheres. It is found that, in this system, the two depletion forces are coupled with each other and result in a strengthened depletion force. So the difference of the depletion forces of the three-sphere system and its corresponding two two-sphere systems is introduced to describe the coupling effect of the depletion interactions. The numerical results obtained by Monte-Carlo simulations show that this coupling effect is affected by both the concentration of small spheres and the geometrical confinement. Meanwhile, it is also found that the mechanisms of the coupling effect and the effect on the depletion force from the geometry factor are the same. (interdisciplinary physics and related areas of science and technology)

  5. Coalescence and Interaction of Solitons in the Coupled Korteweg-de Vries System

    Science.gov (United States)

    Chung, Wai Choi; Chow, Kwok Wing

    2017-11-01

    There are many physical systems which are governed by the classical Korteweg-de Vries equation. One of the prominent examples is the shallow water wave in fluid dynamics. In recent years, a coupled Korteweg-de Vries system has been proposed to describe fluids in a two-layer flow, and coherent structures in terms of solitons are found. We studied the coupled Korteweg-de Vries system by means of the Hirota bilinear method. Soliton and breather solutions are constructed. Localized pulses which result from the coupling of waves can be formed. The structure of the localized pulses becomes asymmetric as the control parameter varies. The coalescence and interaction of solitons in the coupled Korteweg-de Vries system will be discussed. Partial financial support has been provided by the Research Grants Council contract HKU 17200815.

  6. Coupled dynamics of interacting spin-1 bosons in a double-well potential

    Science.gov (United States)

    Carvalho, D. W. S.; Foerster, A.; Gusmão, M. A.

    2018-03-01

    We present a detailed analysis of dynamical processes involving two or three particles in a double-well potential. Motivated by experimental realizations of such a system with optically trapped cold atoms, we focus on spin-1 bosons with special attention on the effects of a spin-dependent interaction in addition to the usual Hubbard-like repulsive one. For a sufficiently weak tunneling amplitude in comparison to the dominant Hubbard coupling, particle motion is strongly correlated, occurring only under fine-tuned relationships between well-depth asymmetry and interactions. We highlight processes involving tunneling of coupled particle pairs and triads, emphasizing the role of the spin-dependent interaction in resonance conditions.

  7. Light-matter interaction in the strong coupling regime: configurations, conditions, and applications.

    Science.gov (United States)

    Dovzhenko, D S; Ryabchuk, S V; Rakovich, Yu P; Nabiev, I R

    2018-02-22

    Resonance interaction between a molecular transition and a confined electromagnetic field can reach the coupling regime where coherent exchange of energy between light and matter becomes reversible. In this case, two new hybrid states separated in energy are formed instead of independent eigenstates, which is known as Rabi splitting. This modification of the energy spectra of the system offers new possibilities for controlled impact on various fundamental properties of coupled matter (such as the rate of chemical reactions and the conductivity of organic semiconductors). To date, the strong coupling regime has been demonstrated in many configurations under different ambient conditions. However, there is still no comprehensive approach to determining parameters for achieving the strong coupling regime for a wide range of practical applications. In this review, a detailed analysis of various systems and corresponding conditions for reaching strong coupling is carried out and their advantages and disadvantages, as well as the prospects for application, are considered. The review also summarizes recent experiments in which the strong coupling regime has led to new interesting results, such as the possibility of collective strong coupling between X-rays and matter excitation in a periodic array of Fe isotopes, which extends the applications of quantum optics; a strong amplification of the Raman scattering signal from a coupled system, which can be used in surface-enhanced and tip-enhanced Raman spectroscopy; and more efficient second-harmonic generation from the low polaritonic state, which is promising for nonlinear optics. The results reviewed demonstrate great potential for further practical applications of strong coupling in the fields of photonics (low-threshold lasers), quantum communications (switches), and biophysics (molecular fingerprinting).

  8. Intersite Coulomb interaction and Heisenberg exchange

    NARCIS (Netherlands)

    Eder, R; van den Brink, J.; Sawatzky, G.A

    1996-01-01

    Based on exact diagonalization results for small clusters we discuss the effect of intersite Coulomb repulsion in Mott-Hubbard or charge transfers insulators. Whereas the exchange constant J for direct exchange is enhanced by intersite Coulomb interaction, that for superexchange is suppressed. The

  9. Validation of a 2-D semi-coupled numerical model for fluid-structure-seabed interaction

    Science.gov (United States)

    Ye, Jianhong; Jeng, Dongsheng; Wang, Ren; Zhu, Changqi

    2013-10-01

    A 2-D semi-coupled model PORO-WSSI 2D (also be referred as FSSI-CAS 2D) for the Fluid-Structure-Seabed Interaction (FSSI) has been developed by employing RANS equations for wave motion in fluid domain, VARANS equations for porous flow in porous structures; and taking the dynamic Biot's equations (known as "u - p" approximation) for soil as the governing equations. The finite difference two-step projection method and the forward time difference method are adopted to solve the RANS, VARANS equations; and the finite element method is adopted to solve the "u - p" approximation. A data exchange port is developed to couple the RANS, VARANS equations and the dynamic Biot's equations together. The analytical solution proposed by Hsu and Jeng (1994) and some experiments conducted in wave flume or geotechnical centrifuge in which various waves involved are used to validate the developed semi-coupled numerical model. The sandy bed involved in these experiments is poro-elastic or poro-elastoplastic. The inclusion of the interaction between fluid, marine structures and poro-elastoplastic seabed foundation is a special point and highlight in this paper, which is essentially different with other previous coupled models The excellent agreement between the numerical results and the experiment data indicates that the developed coupled model is highly reliablefor the FSSI problem.

  10. The XYZ chain with Dzyaloshinsky–Moriya interactions: from spin–orbit-coupled lattice bosons to interacting Kitaev chains

    International Nuclear Information System (INIS)

    Peotta, Sebastiano; Mazza, Leonardo; Fazio, Rosario; Rossini, Davide; Vicari, Ettore; Polini, Marco

    2014-01-01

    Using the density-matrix renormalization group algorithm (DMRG) and a finite-size scaling analysis, we study the properties of the one-dimensional completely anisotropic spin-1/2 XYZ model with Dzyaloshinsky-Moriya (DM) interactions. The model shows a rich phase diagram: depending on the value of the coupling constants, the system can display different kinds of ferromagnetic order and Luttinger liquid behavior. Transitions from ferromagnetic to Luttinger liquid phases are first order. We thoroughly discuss the transition between different ferromagnetic phases, which, in the absence of DM interactions, belongs to the XX universality class. We provide evidence that the DM exchange term splits this critical line into two separated Ising-like transitions and that in between a disordered phase may appear. Our study sheds light on the general problem of strongly interacting spin–orbit-coupled bosonic gases trapped in an optical lattice and can be used to characterize the topological properties of superconducting nanowires in the presence of an imposed supercurrent and of interactions. (paper)

  11. Conflict and Collaboration in Middle-Aged and Older Couples: II: Cardiovascular Reactivity during Marital Interaction

    Science.gov (United States)

    Smith, Timothy W.; Uchino, Bert N.; Berg, Cynthia A.; Florsheim, Paul; Pearce, Gale; Hawkins, Melissa; Henry, Nancy J. M.; Beveridge, Ryan M.; Skinner, Michelle A.; Ko, Kelly J.; Olsen-Cerny, Chrisanna

    2011-01-01

    Marital strain confers risk of cardiovascular disease (CVD), perhaps though cardiovascular reactivity (CVR) to stressful marital interactions. CVR to marital stressors may differ between middle-age and older adults, and types of marital interactions that evoke CVR may also differ across these age groups, as relationship contexts and stressors differ with age. We examined cardiovascular responses to a marital conflict discussion and collaborative problem solving in 300 middle-aged and older married couples. Marital conflict evoked greater increases in blood pressure, cardiac output and cardiac sympathetic activation than did collaboration. Older couples displayed smaller heart rate responses to conflict than did middle-aged couples, but larger blood pressure responses to collaboration–especially older men. These effects were maintained during a post-task recovery period. Women did not display greater CVR than men on any measure or in either interaction context, though they did display greater parasympathetic withdrawal. CVR to marital conflict could contribute to the association of marital strain with CVD for middle-aged and older men and women, but other age-related marital contexts (e.g., collaboration among older couples) may also contribute to this mechanism. PMID:19485647

  12. Conflict and collaboration in middle-aged and older couples: II. Cardiovascular reactivity during marital interaction.

    Science.gov (United States)

    Smith, Timothy W; Uchino, Bert N; Berg, Cynthia A; Florsheim, Paul; Pearce, Gale; Hawkins, Melissa; Henry, Nancy J M; Beveridge, Ryan M; Skinner, Michelle A; Ko, Kelly J; Olsen-Cerny, Chrisanna

    2009-06-01

    Marital strain confers risk of cardiovascular disease (CVD), perhaps though cardiovascular reactivity (CVR) to stressful marital interactions. CVR to marital stressors may differ between middle-age and older adults, and types of marital interactions that evoke CVR may also differ across these age groups, as relationship contexts and stressors differ with age. The authors examined cardiovascular responses to a marital conflict discussion and collaborative problem solving in 300 middle-aged and older married couples. Marital conflict evoked greater increases in blood pressure, cardiac output, and cardiac sympathetic activation than did collaboration. Older couples displayed smaller heart rate responses to conflict than did middle-aged couples but larger blood pressure responses to collaboration-especially in older men. These effects were maintained during a posttask recovery period. Women did not display greater CVR than men on any measure or in either interaction context, though they did display greater parasympathetic withdrawal. CVR to marital conflict could contribute to the association of marital strain with CVD for middle-aged and older men and women, but other age-related marital contexts (e.g., collaboration among older couples) may also contribute to this mechanism. (c) 2009 APA, all rights reserved.

  13. Dynamic interaction of monowheel inclined vehicle-vibration platform coupled system with quadratic and cubic nonlinearities

    Science.gov (United States)

    Zhou, Shihua; Song, Guiqiu; Sun, Maojun; Ren, Zhaohui; Wen, Bangchun

    2018-01-01

    In order to analyze the nonlinear dynamics and stability of a novel design for the monowheel inclined vehicle-vibration platform coupled system (MIV-VPCS) with intermediate nonlinearity support subjected to a harmonic excitation, a multi-degree of freedom lumped parameter dynamic model taking into account the dynamic interaction of the MIV-VPCS with quadratic and cubic nonlinearities is presented. The dynamical equations of the coupled system are derived by applying the displacement relationship, interaction force relationship at the contact position and Lagrange's equation, which are further discretized into a set of nonlinear ordinary differential equations with coupled terms by Galerkin's truncation. Based on the mathematical model, the coupled multi-body nonlinear dynamics of the vibration system is investigated by numerical method, and the parameters influences of excitation amplitude, mass ratio and inclined angle on the dynamic characteristics are precisely analyzed and discussed by bifurcation diagram, Largest Lyapunov exponent and 3-D frequency spectrum. Depending on different ranges of system parameters, the results show that the different motions and jump discontinuity appear, and the coupled system enters into chaotic behavior through different routes (period-doubling bifurcation, inverse period-doubling bifurcation, saddle-node bifurcation and Hopf bifurcation), which are strongly attributed to the dynamic interaction of the MIV-VPCS. The decreasing excitation amplitude and inclined angle could reduce the higher order bifurcations, and effectively control the complicated nonlinear dynamic behaviors under the perturbation of low rotational speed. The first bifurcation and chaotic motion occur at lower value of inclined angle, and the chaotic behavior lasts for larger intervals with higher rotational speed. The investigation results could provide a better understanding of the nonlinear dynamic behaviors for the dynamic interaction of the MIV-VPCS.

  14. Coupling of impedance functions to nuclear reactor building for soil-structure interaction analysis

    International Nuclear Information System (INIS)

    Danisch, R.; Delinic, K.; Trbojevic, V.M.

    1991-01-01

    Finite element model of a nuclear reactor building is coupled to complex soil impedance functions and soil-structure-interaction analysis is carried out in frequency domain. In the second type of analysis applied in this paper, soil impedance functions are used to evaluate equivalent soil springs and dashpots of soil. These are coupled to the structure model in order to carry out the time marching analysis. Three types of soil profiles are considered: hard, medium and soft. Results of two analyzes are compared on the same structural model. Equivalent soil springs and dashpots are determined using new method based on the least square approximation. (author)

  15. Analysis on Patterns of Globally Coupled Phase Oscillators with Attractive and Repulsive Interactions

    International Nuclear Information System (INIS)

    Wang Peng-Fei; Xu Zhong-Bin; Ruan Xiao-Dong; Fu Xin

    2015-01-01

    The Hong–Strogatz (HS) model of globally coupled phase oscillators with attractive and repulsive interactions reflects the fact that each individual (oscillator) has its own attitude (attractive or repulsive) to the same environment (mean field). Previous studies on HS model focused mainly on the stable states on Ott–Antonsen (OA) manifold. In this paper, the eigenvalues of the Jacobi matrix of each fixed point in HS model are explicitly derived, with the aim to understand the local dynamics around each fixed point. Phase transitions are described according to relative population and coupling strength. Besides, the dynamics off OA manifold is studied. (paper)

  16. Azobenzene dye-coupled quadruply hydrogen-bonding modules as colorimetric indicators for supramolecular interactions

    Directory of Open Access Journals (Sweden)

    Yagang Zhang

    2012-04-01

    Full Text Available The facile coupling of azobenzene dyes to the quadruply hydrogen-bonding modules 2,7-diamido-1,8-naphthyridine (DAN and 7-deazaguanine urea (DeUG is described. The coupling of azobenzene dye 2 to mono-amido DAN units 4, 7, and 9 was effected by classic 4-(dimethylaminopyridine (DMAP-catalyzed peptide synthesis with N-(3-dimethylaminopropyl-N’-ethyl carbodiimide hydrochloride (EDC as activating agent, affording the respective amide products 5, 8, and 10 in 60–71% yield. The amide linkage was formed through either the aliphatic or aromatic ester group of 2, allowing both the flexibility and absorption maximum to be tuned. Azobenzene dye 1 was coupled to the DeUG unit 11 by Steglich esterification to afford the product amide 12 in 35% yield. Alternatively, azobenzene dye 16 underwent a room-temperature copper-catalyzed azide–alkyne Huisgen cycloaddition with DeUG alkyne 17 to give triazole 18 in 71% yield. Azobenzene coupled DAN modules 5, 8, and 10 are bright orange–red in color, and azobenzene coupled DeUG modules 12 and 18 are orange–yellow in color. Azobenzene coupled DAN and DeUG modules were successfully used as colorimetric indicators for specific DAN–DeUG and DAN–UPy (2-ureido-4(1H-pyrimidone quadruply hydrogen-bonding interactions.

  17. Mean-field behavior in coupled oscillators with attractive and repulsive interactions.

    Science.gov (United States)

    Hong, Hyunsuk; Strogatz, Steven H

    2012-05-01

    We consider a variant of the Kuramoto model of coupled oscillators in which both attractive and repulsive pairwise interactions are allowed. The sign of the coupling is assumed to be a characteristic of a given oscillator. Specifically, some oscillators repel all the others, thus favoring an antiphase relationship with them. Other oscillators attract all the others, thus favoring an in-phase relationship. The Ott-Antonsen ansatz is used to derive the exact low-dimensional dynamics governing the system's long-term macroscopic behavior. The resulting analytical predictions agree with simulations of the full system. We explore the effects of changing various parameters, such as the width of the distribution of natural frequencies and the relative strengths and proportions of the positive and negative interactions. For the particular model studied here we find, unexpectedly, that the mixed interactions produce no new effects. The system exhibits conventional mean-field behavior and displays a second-order phase transition like that found in the original Kuramoto model. In contrast to our recent study of a different model with mixed interactions [Phys. Rev. Lett. 106, 054102 (2011)], the π state and traveling-wave state do not appear for the coupling type considered here.

  18. DataSpaces: An Interaction and Coordination Framework for Coupled Simulation Workflows

    International Nuclear Information System (INIS)

    Docan, Ciprian; Klasky, Scott A.; Parashar, Manish

    2010-01-01

    Emerging high-performance distributed computing environments are enabling new end-to-end formulations in science and engineering that involve multiple interacting processes and data-intensive application workflows. For example, current fusion simulation efforts are exploring coupled models and codes that simultaneously simulate separate application processes, such as the core and the edge turbulence, and run on different high performance computing resources. These components need to interact, at runtime, with each other and with services for data monitoring, data analysis and visualization, and data archiving. As a result, they require efficient support for dynamic and flexible couplings and interactions, which remains a challenge. This paper presents Data-Spaces, a flexible interaction and coordination substrate that addresses this challenge. DataSpaces essentially implements a semantically specialized virtual shared space abstraction that can be associatively accessed by all components and services in the application workflow. It enables live data to be extracted from running simulation components, indexes this data online, and then allows it to be monitored, queried and accessed by other components and services via the space using semantically meaningful operators. The underlying data transport is asynchronous, low-overhead and largely memory-to-memory. The design, implementation, and experimental evaluation of DataSpaces using a coupled fusion simulation workflow is presented.

  19. Simulation of fluid-structure interaction in micropumps by coupling of two commercial finite element programs

    Science.gov (United States)

    Klein, Andreas; Gerlach, Gerald

    1998-09-01

    This paper deals with the simulation of the fluid-structure interaction phenomena in micropumps. The proposed solution approach is based on external coupling of two different solvers, which are considered here as `black boxes'. Therefore, no specific intervention is necessary into the program code, and solvers can be exchanged arbitrarily. For the realization of the external iteration loop, two algorithms are considered: the relaxation-based Gauss-Seidel method and the computationally more extensive Newton method. It is demonstrated in terms of a simplified test case, that for rather weak coupling, the Gauss-Seidel method is sufficient. However, by simply changing the considered fluid from air to water, the two physical domains become strongly coupled, and the Gauss-Seidel method fails to converge in this case. The Newton iteration scheme must be used instead.

  20. Linking hearts and minds in couple interactions: intentions, attributions, and overriding sentiments.

    Science.gov (United States)

    Waldinger, Robert J; Schulz, Marc S

    2006-09-01

    This study examined the role of emotion and relationship satisfaction in shaping attributions about a partner's intentions in couple interactions. Using video recall, participants (N = 156 couples) reported on their own and their partner's intentions and emotions during affective moments of a discussion about an upsetting event. Links were found between relationship satisfaction and factor-analytically derived intention and attribution scales. Attributions about a partner's intentions were weakly to moderately correlated with the partner's self-reported intentions. Relationship satisfaction accounted for part of the discrepancy between self-reported intentions and partner attributions. Emotions mediated the links between relationship satisfaction and attributions, suggesting that clinicians working with distressed couples should pay more attention to the emotional climate in which attributions are made. Copyright (c) 2006 APA, all rights reserved.

  1. Structure of the neutral current coupling in high energy neutrino--nucleon interactions

    International Nuclear Information System (INIS)

    Merritt, F.S.

    1977-01-01

    The primary objective of this experiment was to determine the Lorentz structure of the neutral current coupling--that is, to determine what combination of V-A and V+A (or possibly S, P, and T) components make up the neutral coupling. The experiment used the Fermilab narrow band neutrino beam to provide separated neutrino and antineutrino fluxes, each consisting of two energy bands at approximately equal to 55 and approximately equal to 150 GeV. Deep inelastic inclusive neutrino-nucleon interactions of the form ν(anti ν) + N = μ - (μ + ) + hadrons (CC event) ν(anti ν) + N = ν(anti ν) + hadrons (NC event) were observed in an instrumented steel target-calorimeter, which measured the total energy of the hadrons produced in each event. The neutral current coupling was determined by comparing the hadron energy distributions of neutrino and antineutrino neutral current events. An analysis of the charged-current data was carried out in order to determine the background of charged-current events with unobserved muons, and to provide a normalization for the neutral current data. Various parameterizations of the CC interaction were tested, and their effects on the neutral current analysis were studied in detail. The neutral current analysis indicates that, if only vector and axial-vector components exist, then the neutral current coupling lies between V and V-A. A pure scalar coupling is excluded. The data were compared to the Weinberg--Salam theory (extended to semileptonic interactions), and are in very good agreement with its predictions. Comparison of these data to the low energy Gargamelle data indicates consistency with a scaling hypothesis

  2. Interacting Dark Matter and q-Deformed Dark Energy Nonminimally Coupled to Gravity

    Directory of Open Access Journals (Sweden)

    Emre Dil

    2016-01-01

    Full Text Available In this paper, we propose a new approach to study the dark sector of the universe by considering the dark energy as an emerging q-deformed bosonic scalar field which is not only interacting with the dark matter, but also nonminimally coupled to gravity, in the framework of standard Einsteinian gravity. In order to analyze the dynamic of the system, we first give the quantum field theoretical description of the q-deformed scalar field dark energy and then construct the action and the dynamical structure of this interacting and nonminimally coupled dark sector. As a second issue, we perform the phase-space analysis of the model to check the reliability of our proposal by searching the stable attractor solutions implying the late-time accelerating expansion phase of the universe.

  3. Final Report. Coupled simulations of Antarctic Ice-sheet/ocean interactions using POP and CISM

    Energy Technology Data Exchange (ETDEWEB)

    Asay-Davis, Xylar Storm [Potsdam Institute for Climate Impact Research, Potdam (Germany)

    2015-12-30

    The project performed under this award, referred to from here on as CLARION (CoupLed simulations of Antarctic Ice-sheet/Ocean iNteractions), included important advances in two models of ice sheet and ocean interactions. Despite its short duration (one year), the project made significant progress on its three major foci. First, together with collaborator Daniel Martin at Lawrence Berkeley National Laboratory (LBNL), I developed the POPSICLES coupled ice sheet-ocean model to the point where it could perform a number of pan-Antarctic simulations under various forcing conditions. The results were presented at a number of major conferences and workshops worldwide, and are currently being incorporated into two manuscripts in preparation.

  4. Coupled quintessence and the impossibility of an interaction: a dynamical analysis study

    Energy Technology Data Exchange (ETDEWEB)

    Bernardi, Fabrizio F.; Landim, Ricardo G. [Universidade de Sao Paulo, Instituto de Fisica, Caixa Postal 66318, Sao Paulo, SP (Brazil)

    2017-05-15

    We analyze the coupled quintessence in the light of the linear dynamical systems theory, with two different interactions: (1) proportional to the energy density of the dark energy and (2) proportional to the sum of the energy densities of the dark matter and dark energy. The results presented here enlarge the previous analyses in the literature, wherein the interaction has been only proportional to the energy density of the dark matter. In the first case it is possible to get the well-known sequence of cosmological eras. For the second interaction only the radiation and the dark-energy era can be described by the fixed points. Therefore, from the point of view of dynamical system theory, the interaction proportional to the sum of the energy densities of the dark matter and dark energy does not describe the universe we live in. (orig.)

  5. Coupled quintessence and the impossibility of an interaction: a dynamical analysis study

    International Nuclear Information System (INIS)

    Bernardi, Fabrizio F.; Landim, Ricardo G.

    2017-01-01

    We analyze the coupled quintessence in the light of the linear dynamical systems theory, with two different interactions: (1) proportional to the energy density of the dark energy and (2) proportional to the sum of the energy densities of the dark matter and dark energy. The results presented here enlarge the previous analyses in the literature, wherein the interaction has been only proportional to the energy density of the dark matter. In the first case it is possible to get the well-known sequence of cosmological eras. For the second interaction only the radiation and the dark-energy era can be described by the fixed points. Therefore, from the point of view of dynamical system theory, the interaction proportional to the sum of the energy densities of the dark matter and dark energy does not describe the universe we live in. (orig.)

  6. Personal Well-Being and Family Interactions of Working Couples With Preschool Children: A Correlational Study

    Directory of Open Access Journals (Sweden)

    Danila Secolim Coser

    2013-09-01

    Full Text Available This study’s objective was to verify potential relationships among personal well-being, parental practices, and interactions between parents and preschool children reported by working fathers and mothers ( n = 120, 60 couples from a city in the interior of São Paulo, Brazil. Data were collected using the Questionnaire on family and professional lives. Three scales were selected for data analysis: well-being; interaction between parents and children; and family life. Statistical tests (One-Way ANOVA and Pearson’s correlation coefficient showed negative correlations between child-rearing practices and health problems reported by parents. Positive correlations were also found between reported parental interactions and child-rearing practices. Parental practices and interactions between parents and children varied according to the number of children (one or two.

  7. Thermodynamic model of a solid with RKKY interaction and magnetoelastic coupling

    Science.gov (United States)

    Balcerzak, T.; Szałowski, K.; Jaščur, M.

    2018-04-01

    Thermodynamic description of a model system with magnetoelastic coupling is presented. The elastic, vibrational, electronic and magnetic energy contributions are taken into account. The long-range RKKY interaction is considered together with the nearest-neighbour direct exchange. The generalized Gibbs potential and the set of equations of state are derived, from which all thermodynamic functions are self-consistently obtained. Thermodynamic properties are calculated numerically for FCC structure for arbitrary external pressure, magnetic field and temperature, and widely discussed. In particular, for some parameters of interaction potential and electron concentration corresponding to antiferromagnetic phase, the existence of negative thermal expansion coefficient is predicted.

  8. Emergence of global scaling behaviour in the coupled Earth-atmosphere interaction

    OpenAIRE

    Fallah, Bijan; Saberi, Abbas Ali; Sodoudi, Sahar

    2016-01-01

    Scale invariance property in the global geometry of Earth may lead to a coupled interactive behaviour between various components of the climate system. One of the most interesting correlations exists between spatial statistics of the global topography and the temperature on Earth. Here we show that the power-law behaviour observed in the Earth topography via different approaches, resembles a scaling law in the global spatial distribution of independent atmospheric parameters. We report on obs...

  9. Characterization of interaction between U-Mo alloy and Al diffusion-couple

    International Nuclear Information System (INIS)

    Liu Yunming; Yin Changgeng; Sun Changlong; Chen Jiangang; Sun Xudong

    2011-01-01

    In this paper, the interaction behavior of U-Mo/Al was studied with the diffusion-couple method, and the couple was continuously jointed by hot-pressing with special device. Annealing experiments were accomplished in a vacuum hot-pressing furnace, and at 550∼570℃ for 5∼21 hours. The results show that the morphology and composition of interaction Layer depend on the interaction layer thickness. The content of U (Mo) and Al is mutational at the interface of U-Mo/interaction layer/Al. The layer close to U-Mo side is mainly composed of product (U, Mo)Al 3 , while the Al side is composed of (U, Mo)Al 4 and UMO 2 Al 20 . Diffusion process of U-Mo/Al is Al immigrating over the Al/U-Mo original interface into U-Mo side and reacting with U-Mo, subsequently the interaction layer is growing into Al. (authors)

  10. A Coupled Fluid-Structure Interaction Analysis of Solid Rocket Motor with Flexible Inhibitors

    Science.gov (United States)

    Yang, H. Q.; West, Jeff

    2014-01-01

    A capability to couple NASA production CFD code, Loci/CHEM, with CFDRC's structural finite element code, CoBi, has been developed. This paper summarizes the efforts in applying the installed coupling software to demonstrate/investigate fluid-structure interaction (FSI) between pressure wave and flexible inhibitor inside reusable solid rocket motor (RSRM). First a unified governing equation for both fluid and structure is presented, then an Eulerian-Lagrangian framework is described to satisfy the interfacial continuity requirements. The features of fluid solver, Loci/CHEM and structural solver, CoBi, are discussed before the coupling methodology of the solvers is described. The simulation uses production level CFD LES turbulence model with a grid resolution of 80 million cells. The flexible inhibitor is modeled with full 3D shell elements. Verifications against analytical solutions of structural model under steady uniform pressure condition and under dynamic condition of modal analysis show excellent agreements in terms of displacement distribution and eigen modal frequencies. The preliminary coupled result shows that due to acoustic coupling, the dynamics of one of the more flexible inhibitors shift from its first modal frequency to the first acoustic frequency of the solid rocket motor.

  11. Spin-orbit coupling effects, interactions and superconducting transport in nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Andreas

    2010-05-15

    In the present thesis we study the electronic properties of several low dimensional nanoscale systems. In the first part, we focus on the combined effect of spin-orbit coupling (SOI) and Coulomb interaction in carbon nanotubes (CNTs) as well as quantum wires. We derive low energy theories for both systems, using the bosonization technique and obtain analytic expressions for the correlation functions that allow us to compute basically all observables of interest. We first focus on CNTs and show that a four channel Luttinger liquid theory can still be applied when SOI effects are taken into account. Compared to previous formulations, the low-energy Hamiltonian is characterized by different Luttinger parameters and plasmon velocities. Notably, the charge and spin modes are coupled. Our theory allows us to compute an asymptotically exact expression for the spectral function of a metallic carbon nanotube. We find modifications to the previously predicted structure of the spectral function that can in principle be tested by photoemission spectroscopy experiments. We develop a very similar low energy description for an interacting quantum wire subject to Rashba spin-orbit coupling (RSOC). We derive a two component Luttinger liquid Hamiltonian in the presence of RSOC, taking into account all e-e interaction processes allowed by the conservation of total momentum. The effective low energy Hamiltonian includes an additional perturbation due to intraband backscattering processes with band flip. Within a one-loop RG scheme, this perturbation is marginally irrelevant. The fixed point model is then still a two channel Luttinger liquid, albeit with a non standard form due to SOI. Again, the charge and spin mode are coupled. Using our low energy theory, we address the problem of the RKKY interaction in an interacting Rashba wire. The coupling of spin and charge modes due to SO effects implies several modifications, e.g. the explicit dependence of the power-law decay exponent of

  12. Spin-orbit coupling effects, interactions and superconducting transport in nanostructures

    International Nuclear Information System (INIS)

    Schulz, Andreas

    2010-05-01

    In the present thesis we study the electronic properties of several low dimensional nanoscale systems. In the first part, we focus on the combined effect of spin-orbit coupling (SOI) and Coulomb interaction in carbon nanotubes (CNTs) as well as quantum wires. We derive low energy theories for both systems, using the bosonization technique and obtain analytic expressions for the correlation functions that allow us to compute basically all observables of interest. We first focus on CNTs and show that a four channel Luttinger liquid theory can still be applied when SOI effects are taken into account. Compared to previous formulations, the low-energy Hamiltonian is characterized by different Luttinger parameters and plasmon velocities. Notably, the charge and spin modes are coupled. Our theory allows us to compute an asymptotically exact expression for the spectral function of a metallic carbon nanotube. We find modifications to the previously predicted structure of the spectral function that can in principle be tested by photoemission spectroscopy experiments. We develop a very similar low energy description for an interacting quantum wire subject to Rashba spin-orbit coupling (RSOC). We derive a two component Luttinger liquid Hamiltonian in the presence of RSOC, taking into account all e-e interaction processes allowed by the conservation of total momentum. The effective low energy Hamiltonian includes an additional perturbation due to intraband backscattering processes with band flip. Within a one-loop RG scheme, this perturbation is marginally irrelevant. The fixed point model is then still a two channel Luttinger liquid, albeit with a non standard form due to SOI. Again, the charge and spin mode are coupled. Using our low energy theory, we address the problem of the RKKY interaction in an interacting Rashba wire. The coupling of spin and charge modes due to SO effects implies several modifications, e.g. the explicit dependence of the power-law decay exponent of

  13. Self-organization of grafted polyelectrolyte layers via the coupling of chemical equilibrium and physical interactions.

    Science.gov (United States)

    Tagliazucchi, Mario; de la Cruz, Mónica Olvera; Szleifer, Igal

    2010-03-23

    The competition between chemical equilibrium, for example protonation, and physical interactions determines the molecular organization and functionality of biological and synthetic systems. Charge regulation by displacement of acid-base equilibrium induced by changes in the local environment provides a feedback mechanism that controls the balance between electrostatic, van der Waals, steric interactions and molecular organization. Which strategies do responsive systems follow to globally optimize chemical equilibrium and physical interactions? We address this question by theoretically studying model layers of end-grafted polyacids. These layers spontaneously form self-assembled aggregates, presenting domains of controlled local pH and whose morphologies can be manipulated by the composition of the solution in contact with the film. Charge regulation stabilizes micellar domains over a wide range of pH by reducing the local charge in the aggregate at the cost of chemical free energy and gaining in hydrophobic interactions. This balance determines the boundaries between different aggregate morphologies. We show that a qualitatively new form of organization arises from the coupling between physical interactions and protonation equilibrium. This optimization strategy presents itself with polyelectrolytes coexisting in two different and well-defined protonation states. Our results underline the need of considering the coupling between chemical equilibrium and physical interactions due to their highly nonadditive behavior. The predictions provide guidelines for the creation of responsive polymer layers presenting self-organized patterns with functional properties and they give insights for the understanding of competing interactions in highly inhomogeneous and constrained environments such as those relevant in nanotechnology and those responsible for biological cells function.

  14. A FEM-BEM interactive coupling for modeling the piezoelectric health monitoring systems

    Directory of Open Access Journals (Sweden)

    Abid A. Shah

    Full Text Available In this research, finite element and boundary element methods are coupled together to model the interaction of a piezoelectric ceramic working as an actuator with an elastic material. Piezoelectric-elastic material's interaction occurs in smart structures. This work is aimed at determining the actuation effects being transferred from the actuators to the host and the resulting overall structural response. To obtain the amount of these actuations, the system of the host structure and an actuator has been modeled by using coupled finite element boundary element method in frequency domain. The host structure, which is assumed as an isotropic elastic solid region is modeled as a half space. The piezoelectric ceramic region is modeled by the 3-D finite element method, while the elastic half space with boundary element method. Finite element model of piezoelectric ceramic and boundary element model of the elastic half space are coupled together at their interface such that the vibrations of the piezo-actuator induce vibrations in the elastic half space. A couple of examples are given to show the induced displacement field around the piezo-actuator on the surface of the elastic medium. The results show that high jump in magnitude of horizontal displacements at the corners of the actuator attached to the structure occurs, which is an indication of high stress concentration, of the shear stress type at the corners. This stress concentration sometimes causes complete debonding of the actuator from the base structure. By using the suggested BEM-FEM coupled model for actuators with different dimensions or material properties much useful information concerning the amount of actuation and load transfer can be obtained. The presented work is a step towards modeling of structural health monitoring systems.

  15. Coupled Fluid-Structure Interaction Analysis of Solid Rocket Motor with Flexible Inhibitors

    Science.gov (United States)

    Yang, H. Q.; West, Jeff; Harris, Robert E.

    2014-01-01

    Flexible inhibitors are generally used in solid rocket motors (SRMs) as a means to control the burning of propellant. Vortices generated by the flow of propellant around the flexible inhibitors have been identified as a driving source of instabilities that can lead to thrust oscillations in launch vehicles. Potential coupling between the SRM thrust oscillations and structural vibration modes is an important risk factor in launch vehicle design. As a means to predict and better understand these phenomena, a multidisciplinary simulation capability that couples the NASA production CFD code, Loci/CHEM, with CFDRC's structural finite element code, CoBi, has been developed. This capability is crucial to the development of NASA's new space launch system (SLS). This paper summarizes the efforts in applying the coupled software to demonstrate and investigate fluid-structure interaction (FSI) phenomena between pressure waves and flexible inhibitors inside reusable solid rocket motors (RSRMs). The features of the fluid and structural solvers are described in detail, and the coupling methodology and interfacial continuity requirements are then presented in a general Eulerian-Lagrangian framework. The simulations presented herein utilize production level CFD with hybrid RANS/LES turbulence modeling and grid resolution in excess of 80 million cells. The fluid domain in the SRM is discretized using a general mixed polyhedral unstructured mesh, while full 3D shell elements are utilized in the structural domain for the flexible inhibitors. Verifications against analytical solutions for a structural model under a steady uniform pressure condition and under dynamic modal analysis show excellent agreement in terms of displacement distribution and eigenmode frequencies. The preliminary coupled results indicate that due to acoustic coupling, the dynamics of one of the more flexible inhibitors shift from its first modal frequency to the first acoustic frequency of the solid rocket motor

  16. Asymmetric Partner Pronoun Use and Demand-Withdraw Interaction in Couples Coping with Health Problems

    Science.gov (United States)

    Rentscher, Kelly E.; Rohrbaugh, Michael J.; Shoham, Varda; Mehl, Matthias R.

    2014-01-01

    Recent research links first-person plural pronoun use (we-talk) by individual romantic partners to adaptive relationship functioning and individual health outcomes. To examine a possible boundary condition of adaptive we-talk in couples coping with health problems, we correlated asymmetric couple-level we/I-ratios (more we-talk relative to I-talk by the spouse than the patient) with a concurrent pattern of directional demand-withdraw (D-W) interaction in which the spouse demands change while the patient withdraws. Couples in which a partner who abused alcohol (n = 65), smoked cigarettes despite having heart or lung disease (n = 24), or had congestive heart failure (n = 58) discussed a health-related disagreement during a video-recorded interaction task. Transcripts of these conversations provided measures of pronoun use for each partner, and trained observers coded D-W patterns from the recordings. As expected, partner asymmetry in we/I-ratio scores predicted directional demand-withdraw, such that spouses who used more we-talk (relative to I-talk) than patients tended to assume the demand role in concurrent D-W interaction. Asymmetric I-talk rather than we-talk accounted for this association, and asymmetric you-talk contributed independently as well. In contrast to previous studies of we-talk by individual partners, the present results identify dyad-level pronoun patterns that clearly do not mark beneficent processes: asymmetric partner we/I-ratios and you-talk reflect problematic demand-withdraw interaction. PMID:24098961

  17. An example of coupling behaviour-damage-environment in polycrystals. Application to Pellet-Cladding Interaction

    International Nuclear Information System (INIS)

    Diard, Olivier

    2001-01-01

    Zircaloy-4 cladding is the first containment barrier for fission products, and its integrity must therefore be ensured in nominal and accidental situations. However, stress corrosion induced cracks may appear due to a strong pellet-cladding interaction. It is therefore important to model this interaction and crack growth and propagation to establish non-damage criteria. Thus, this research thesis aims at developing a modelling covering both issues (pellet-cladding interaction, and stress corrosion cracking) and allowing macroscopic and microscopic scales to be coupled. After a bibliographical synthesis on iodine-induced stress corrosion cracking and similar phenomena, the author presents the model proposed for the pellet-cladding interaction: phenomena to be taken into account, phenomenological and macroscopic behaviour laws used respectively for pellet and cladding. An extended version of an existing cladding viscoplastic model is proposed. Stress and strain fields in the cladding are obtained, notably in the contact zone. In the next part, the author presents various numerical tools developed or used to model multi-crystalline aggregates, and the model of crystalline plasticity used to simulate cladding behaviour at the microstructure scale. Effects of mesh density, element types and anisotropic elasticity are also discussed. The next chapter addresses the mechanical-chemical coupling. Some coupling formulas are presented for simple cases in order to define the effective diffusion coefficient. The last part reports the modelling of intergranular damage: definition of a damage criterion at the granular scale, assessment of stresses at grain boundaries, and effect of crystallographic neighbouring. A model of grain boundary damage is also proposed. This model is assessed on Failure Mechanics test samples and on simple microstructures. The application of the whole numerical model is reported [fr

  18. Dynamics of interacting Dicke model in a coupled-cavity array

    Science.gov (United States)

    Badshah, Fazal; Qamar, Shahid; Paternostro, Mauro

    2014-09-01

    We consider the dynamics of an array of mutually interacting cavities, each containing an ensemble of N two-level atoms. By exploring the possibilities offered by ensembles of various dimensions and a range of atom-light and photon-hopping values, we investigate the generation of multisite entanglement, as well as the performance of excitation transfer across the array, resulting from the competition between on-site nonlinearities of the matter-light interaction and intersite photon hopping. In particular, for a three-cavity interacting system it is observed that the initial excitation in the first cavity completely transfers to the ensemble in the third cavity through the hopping of photons between the adjacent cavities. Probabilities of the transfer of excitation of the cavity modes and ensembles exhibit characteristics of fast and slow oscillations governed by coupling and hopping parameters, respectively. In the large-hopping case, by seeding an initial excitation in the cavity at the center of the array, a tripartite W state, as well as a bipartite maximally entangled state, is obtained, depending on the interaction time. Population of the ensemble in a cavity has a positive impact on the rate of excitation transfer between the ensembles and their local cavity modes. In particular, for ensembles of five to seven atoms, tripartite W states can be produced even when the hopping rate is comparable to the cavity-atom coupling rate. A similar behavior of the transfer of excitation is observed for a four-coupled-cavity system with two initial excitations.

  19. Microprobe PIXE study of Ni–Ge interactions in lateral diffusion couples

    Energy Technology Data Exchange (ETDEWEB)

    Chilukusha, D. [Department of Physics, University of Zambia, P.O. Box 32379, Lusaka 10101 (Zambia); Pineda-Vargas, C.A. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); Faculty of Health & Wellness Sciences, CPUT, Bellville (South Africa); Nemutudi, R. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); Habanyama, A. [Department of Physics, Copperbelt University, P.O. Box 21692, Jambo Drive, Riverside, Kitwe 10101 (Zambia); Comrie, C.M. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa)

    2015-11-15

    Rutherford backscattering spectrometry on the nuclear microprobe (μRBS) is often used in studies of lateral diffusion couples. RBS requires that the positions of the interacting species on the periodic table are not too close in terms of atomic number and therefore do not produce excessive RBS peak overlap. In order to satisfactorily characterize systems that have atomic numbers which are close, it is necessary to find techniques which can complement μRBS. The aim of this study was to determine the extent to which particle induced X-ray emission (PIXE) could be applied in the lateral diffusion couple study of a system with relatively close atomic numbers. This was with a view that it may eventually be adopted to study systems where the atomic numbers are too close for RBS analysis. The system studied here was the Ni–Ge binary system. Since RBS is an established technique for studying lateral diffusion couples, we used it as a standard for comparison. The PIXE results showed a maximum error of 12% with reference to the RBS standard. In order to achieve the most effective use of PIXE in lateral diffusion couple studies we recommend the use of the technique in such a way as to obtain depth information and the use of relatively thick sample layers.

  20. Analysis on Patterns of Globally Coupled Phase Oscillators with Attractive and Repulsive Interactions

    Science.gov (United States)

    Wang, Peng-Fei; Ruan, Xiao-Dong; Xu, Zhong-Bin; Fu, Xin

    2015-11-01

    The Hong-Strogatz (HS) model of globally coupled phase oscillators with attractive and repulsive interactions reflects the fact that each individual (oscillator) has its own attitude (attractive or repulsive) to the same environment (mean field). Previous studies on HS model focused mainly on the stable states on Ott-Antonsen (OA) manifold. In this paper, the eigenvalues of the Jacobi matrix of each fixed point in HS model are explicitly derived, with the aim to understand the local dynamics around each fixed point. Phase transitions are described according to relative population and coupling strength. Besides, the dynamics off OA manifold is studied. Supported by the National Basic Research Program of China under Grant No. 2015CB057301, the Applied Research Project of Public Welfare Technology of Zhejiang Province under Grant No. 201SC31109 and China Postdoctoral Science Foundation under Grant No. 2014M560483

  1. Dealing with Tight Couplings and Multiple Interactions in Complex Technological Systems

    DEFF Research Database (Denmark)

    Aanestad, M.; Jensen, Tina Blegind; Grisot, M.

    In this paper we discuss the challenges of dealing with interdependencies in complex assemblages of heterogeneous and interconnected information systems (IS), which we conceptualize as organizationwide information infrastructures. We draw on Perrow's studies of complex technological systems, where...... couplings between information systems, actors, and work practices in the hospital environment. The paper's main focus is on describing what it entails in practice to deal with these interdependencies during and after implementation. We emphasize the work of sorting out and dealing with various types...... interactions, mechanisms, and couplings are emphasized. We base our paper on an empirical case study from a Norwegian hospital, where a seemingly trivial project aimed at the introduction of scanners turned out to be more complex than expected. This we claim is partly due to the interdependencies and tight...

  2. Exploratory study of possible resonances in heavy meson - heavy baryon coupled-channel interactions

    Science.gov (United States)

    Shen, Chao-Wei; Rönchen, Deborah; Meißner, Ulf-G.; Zou, Bing-Song

    2018-01-01

    We use a unitary coupled-channel model to study the \\bar{{{D}}}{{{Λ }}}{{c}}-\\bar{{{D}}}{{{Σ }}}{{c}} interactions. In our calculation, SU(3) flavor symmetry is applied to determine the coupling constants. Several resonant and bound states with different spin and parity are dynamically generated in the mass range of the recently observed pentaquarks. The approach is also extended to the hidden beauty sector to study the {{B}}{{{Λ }}}{{b}}-{{B}}{{{Σ }}}{{b}} interactions. As the b-quark mass is heavier than the c-quark mass, there are more resonances observed for the {{B}}{{{Λ }}}{{b}}-{{B}}{{{Σ }}}{{b}} interactions and they are more tightly bound. Supported by DFG and NSFC through funds provided to the Sino-German CRC 110 “Symmetry and the Emergence of Structure in QCD” (NSFC 11621131001, DFG TR110), as well as an NSFC fund (11647601). The work of UGM was also supported by the CAS President’s International Fellowship Initiative (PIFI) (2017VMA0025)

  3. How does Interactive Chemistry Influence the Representation of Stratosphere-Troposphere Coupling in a Climate Model?

    Science.gov (United States)

    Haase, S.; Matthes, K. B.

    2017-12-01

    Changes in stratospheric ozone can trigger tropospheric circulation changes. In the Southern hemisphere (SH), the observed shift of the Southern Annular Mode was attributed to the observed trend in lower stratospheric ozone. In the Northern Hemisphere (NH), a recent study showed that extremely low stratospheric ozone conditions during spring produce robust anomalies in the troposphere (zonal wind, temperature and precipitation). This could only be reproduced in a coupled chemistry climate model indicating that chemical-dynamical feedbacks are also important on the NH. To further investigate the importance of interactive chemistry for surface climate, we conducted a set of experiments using NCAR's Community Earth System Model (CESM1) with the Whole Atmosphere Community Climate Model (WACCM) as the atmosphere component. WACCM contains a fully interactive stratospheric chemistry module in its standard configuration. It also allows for an alternative configuration, referred to as SC-WACCM, in which the chemistry (O3, NO, O, O2, CO2 and chemical and shortwave heating rates) is specified as a 2D field in the radiation code. A comparison of the interactive vs. the specified chemistry version enables us to evaluate the relative importance of interactive chemistry by systematically inhibiting the feedbacks between chemistry and dynamics. To diminish the effect of temporal interpolation when prescribing ozone, we use daily resolved zonal mean ozone fields for the specified chemistry run. Here, we investigate the differences in stratosphere-troposphere coupling between the interactive and specified chemistry simulations for the mainly chemically driven SH as well as for the mainly dynamically driven NH. We will especially consider years that are characterized by extremely low stratospheric ozone on the one hand and by large dynamical disturbances, i.e. Sudden Stratospheric Warmings, on the other hand.

  4. Multiphase fluid-solid coupled analysis of shock-bubble-stone interaction in shockwave lithotripsy.

    Science.gov (United States)

    Wang, Kevin G

    2017-10-01

    A novel multiphase fluid-solid-coupled computational framework is applied to investigate the interaction of a kidney stone immersed in liquid with a lithotripsy shock wave (LSW) and a gas bubble near the stone. The main objective is to elucidate the effects of a bubble in the shock path to the elastic and fracture behaviors of the stone. The computational framework couples a finite volume 2-phase computational fluid dynamics solver with a finite element computational solid dynamics solver. The surface of the stone is represented as a dynamic embedded boundary in the computational fluid dynamics solver. The evolution of the bubble surface is captured by solving the level set equation. The interface conditions at the surfaces of the stone and the bubble are enforced through the construction and solution of local fluid-solid and 2-fluid Riemann problems. This computational framework is first verified for 3 example problems including a 1D multimaterial Riemann problem, a 3D shock-stone interaction problem, and a 3D shock-bubble interaction problem. Next, a series of shock-bubble-stone-coupled simulations are presented. This study suggests that the dynamic response of a bubble to LSW varies dramatically depending on its initial size. Bubbles with an initial radius smaller than a threshold collapse within 1 μs after the passage of LSW, whereas larger bubbles do not. For a typical LSW generated by an electrohydraulic lithotripter (p max  = 35.0MPa, p min  =- 10.1MPa), this threshold is approximately 0.12mm. Moreover, this study suggests that a noncollapsing bubble imposes a negative effect on stone fracture as it shields part of the LSW from the stone. On the other hand, a collapsing bubble may promote fracture on the proximal surface of the stone, yet hinder fracture from stone interior. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Dynamics of interacting fermions under spin-orbit coupling in an optical lattice clock

    Science.gov (United States)

    Bromley, S. L.; Kolkowitz, S.; Bothwell, T.; Kedar, D.; Safavi-Naini, A.; Wall, M. L.; Salomon, C.; Rey, A. M.; Ye, J.

    2018-04-01

    Quantum statistics and symmetrization dictate that identical fermions do not interact via s-wave collisions. However, in the presence of spin-orbit coupling (SOC), fermions prepared in identical internal states with distinct momenta become distinguishable. The resulting strongly interacting system can exhibit exotic topological and pairing behaviours, many of which are yet to be observed in condensed matter systems. Ultracold atomic gases offer a promising pathway for simulating these rich phenomena, but until recently have been hindered by heating and losses. Here we enter a new regime of many-body interacting SOC in a fermionic optical lattice clock (OLC), where the long-lived electronic clock states mitigate unwanted dissipation. Using clock spectroscopy, we observe the precession of the collective magnetization and the emergence of spin-locking effects arising from an interplay between p-wave and SOC-induced exchange interactions. The many-body dynamics are well captured by a collective XXZ spin model, which describes a broad class of condensed matter systems ranging from superconductors to quantum magnets. Furthermore, our work will aid in the design of next-generation OLCs by offering a route for avoiding the observed large density shifts caused by SOC-induced exchange interactions.

  6. A conceptual framework to evaluate human-wildlife interactions within coupled human and natural systems

    Directory of Open Access Journals (Sweden)

    Anita T. Morzillo

    2014-09-01

    Full Text Available Landscape characteristics affect human-wildlife interactions. However, there is a need to better understand mechanisms that drive those interactions, particularly feedbacks that exist between wildlife-related impacts, human reaction to and behavior as a result of those impacts, and how land use and landscape characteristics may influence those components within coupled human and natural systems. Current conceptual models of human-wildlife interactions often focus on species population size as the independent variable driving those interactions. Such an approach potentially overlooks important feedbacks among and drivers of human-wildlife interactions that result from mere wildlife presence versus absence. We describe an emerging conceptual framework that focuses on wildlife as a driver of human behavior and allows us to better understand linkages between humans, wildlife, and the broader landscape. We also present results of a pilot analysis related to our own ongoing study of urban rodent control behavior to illustrate one application of this framework within a study of urban landscapes.

  7. Dissipation and entanglement dynamics for two interacting qubits coupled to independent reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Scala, M [Departamento de Optica, Facultad de Fisica, Universidad Complutense de Madrid, 28040 (Spain); Migliore, R [CNR-INFM, CNISM and Dipartimento di Scienze Fisiche ed Astronomiche dell' Universita di Palermo, via Archirafi 36, I-90123 Palermo (Italy); Messina, A [MIUR and Dipartimento di Scienze Fisiche ed Astronomiche dell' Universita di Palermo, via Archirafi 36, I-90123 Palermo (Italy)], E-mail: matteo.scala@fisica.unipa.it, E-mail: rosanna@fisica.unipa.it, E-mail: messina@fisica.unipa.it

    2008-10-31

    We derive the master equation of a system of two coupled qubits by taking into account their interaction with two independent bosonic baths. Important features of the dynamics are brought to light, such as the structure of the stationary state at general temperatures and the behaviour of the entanglement at zero temperature, showing the phenomena of sudden death and sudden birth as well as the presence of stationary entanglement for long times. The model presented here is quite versatile and can be of interest in the study of both Josephson junction architectures and cavity-QED.

  8. Exact solution of a quasi-one-dimensional model with long range interaction (coupled tomonaga chains)

    International Nuclear Information System (INIS)

    Nguyen Minh Khue; Solyom, J.

    1980-03-01

    The novel method proposed by one of the authors to calculate exactly the response functions of the one-dimensional Tomonaga-model is described in more detail. The method is generalized for the case of a system of coupled chains where both the interchain and interchain interactions have forward scattering components only. The model does not show real phase transition at any finite temperature indicating that the interchain backward scattering or hopping is needed to have an ordering of the chains at finite temperature. (author)

  9. Strong coupling electrostatics for randomly charged surfaces: antifragility and effective interactions.

    Science.gov (United States)

    Ghodrat, Malihe; Naji, Ali; Komaie-Moghaddam, Haniyeh; Podgornik, Rudolf

    2015-05-07

    We study the effective interaction mediated by strongly coupled Coulomb fluids between dielectric surfaces carrying quenched, random monopolar charges with equal mean and variance, both when the Coulomb fluid consists only of mobile multivalent counterions and when it consists of an asymmetric ionic mixture containing multivalent and monovalent (salt) ions in equilibrium with an aqueous bulk reservoir. We analyze the consequences that follow from the interplay between surface charge disorder, dielectric and salt image effects, and the strong electrostatic coupling that results from multivalent counterions on the distribution of these ions and the effective interaction pressure they mediate between the surfaces. In a dielectrically homogeneous system, we show that the multivalent counterions are attracted towards the surfaces with a singular, disorder-induced potential that diverges logarithmically on approach to the surfaces, creating a singular but integrable counterion density profile that exhibits an algebraic divergence at the surfaces with an exponent that depends on the surface charge (disorder) variance. This effect drives the system towards a state of lower thermal 'disorder', one that can be described by a renormalized temperature, exhibiting thus a remarkable antifragility. In the presence of an interfacial dielectric discontinuity, the singular behavior of counterion density at the surfaces is removed but multivalent counterions are still accumulated much more strongly close to randomly charged surfaces as compared with uniformly charged ones. The interaction pressure acting on the surfaces displays in general a highly non-monotonic behavior as a function of the inter-surface separation with a prominent regime of attraction at small to intermediate separations. This attraction is caused directly by the combined effects from charge disorder and strong coupling electrostatics of multivalent counterions, which dominate the surface-surface repulsion due to

  10. Discrete and continuum links to a nonlinear coupled transport problem of interacting populations

    Science.gov (United States)

    Duong, M. H.; Muntean, A.; Richardson, O. M.

    2017-07-01

    We are interested in exploring interacting particle systems that can be seen as microscopic models for a particular structure of coupled transport flux arising when different populations are jointly evolving. The scenarios we have in mind are inspired by the dynamics of pedestrian flows in open spaces and are intimately connected to cross-diffusion and thermo-diffusion problems holding a variational structure. The tools we use include a suitable structure of the relative entropy controlling TV-norms, the construction of Lyapunov functionals and particular closed-form solutions to nonlinear transport equations, a hydrodynamics limiting procedure due to Philipowski, as well as the construction of numerical approximates to both the continuum limit problem in 2D and to the original interacting particle systems.

  11. Interaction of ATP with acid-denatured cytochrome c via coupled folding-binding mechanism

    International Nuclear Information System (INIS)

    Ahluwalia, Unnati; Deep, Shashank

    2012-01-01

    Highlights: ► Interaction between ATP and cyt c takes place via coupled binding–folding mechanism. ► Binding of ATP to cyt c is endothermic. ► GTP and CTP induce similar level of helicity in acid-denatured cyt c as with ATP. ► Compactness induced by ATP is far greater than ADP or AMP. - Abstract: The non-native conformations of the cytochrome c (cyt c) are believed to play key roles in a number of physiological processes. Nucleotides are supposed to act as allosteric effectors in these processes by regulating structural transitions among different conformations of cyt c. To understand the interaction between acid denatured cytochrome c and nucleotides, spectroscopic and calorimetric techniques were utilized to observe the structural features of the induced conformation and the energetics of interaction of acid denatured cyt c with different nucleotides. Structure induction in the acid denatured cyt c was observed on the addition of the ∼1 mM nucleotide tri-phosphates (ATP/GTP/CTP) at 25 °C, however, not in the presence of 1 mM nucleotide mono and diphosphates. ATP-bound cyt c at pH 2.0 is likely to have a conformation that has intact α-helical domain. However, Met80-Fe(III) axial bond is still ruptured. Observed thermodynamics reflect interaction between nucleotide and cyt c via coupled binding–folding mechanism. DSC data suggest the preferential binding of the ATP to the folded conformation with respect to the acid denatured cyt c. ITC data indicate that the exothermic folding of cyt c was accompanied by endothermic binding of ATP to cyt c.

  12. Self-interacting asymmetric dark matter coupled to a light massive dark photon

    International Nuclear Information System (INIS)

    Petraki, Kalliopi; Pearce, Lauren; Kusenko, Alexander

    2014-01-01

    Dark matter (DM) with sizeable self-interactions mediated by a light species offers a compelling explanation of the observed galactic substructure; furthermore, the direct coupling between DM and a light particle contributes to the DM annihilation in the early universe. If the DM abundance is due to a dark particle-antiparticle asymmetry, the DM annihilation cross-section can be arbitrarily large, and the coupling of DM to the light species can be significant. We consider the case of asymmetric DM interacting via a light (but not necessarily massless) Abelian gauge vector boson, a dark photon. In the massless dark photon limit, gauge invariance mandates that DM be multicomponent, consisting of positive and negative dark ions of different species which partially bind in neutral dark atoms. We argue that a similar conclusion holds for light dark photons; in particular, we establish that the multi-component and atomic character of DM persists in much of the parameter space where the dark photon is sufficiently light to mediate sizeable DM self-interactions. We discuss the cosmological sequence of events in this scenario, including the dark asymmetry generation, the freeze-out of annihilations, the dark recombination and the phase transition which gives mass to the dark photon. We estimate the effect of self-interactions in DM haloes, taking into account this cosmological history. We place constraints based on the observed ellipticity of large haloes, and identify the regimes where DM self-scattering can affect the dynamics of smaller haloes, bringing theory in better agreement with observations. Moreover, we estimate the cosmological abundance of dark photons in various regimes, and derive pertinent bounds

  13. Conflict and collaboration in middle-aged and older couples: I. Age differences in agency and communion during marital interaction.

    Science.gov (United States)

    Smith, Timothy W; Berg, Cynthia A; Florsheim, Paul; Uchino, Bert N; Pearce, Gale; Hawkins, Melissa; Henry, Nancy J M; Beveridge, Ryan M; Skinner, Michelle A; Olsen-Cerny, Chrisanna

    2009-06-01

    Prior theory and research regarding age differences in marital interaction suggest that older couples display and experience more positivity and less negativity than middle-aged couples. However, studies of overt behavior in older couples are relatively rare and have emphasized disagreement, neglecting other important contexts for older couples such as collaboration during everyday problem solving. Further, the affiliation or communion dimension of social interaction (i.e., warmth vs. hostility) is commonly assessed but not the control or agency dimension (e.g., dominance vs. submissiveness). The present study examined affect, cognitive appraisals, and overt behavior during disagreement (i.e., discussing a current conflict) and collaboration (i.e., planning errands) in 300 middle-aged and older married couples. Older couples reported less negative affect during disagreement and rated spouses as warmer than did middle-aged couples. However, these effects were eliminated when older couples' greater marital satisfaction was controlled. For observed behavior, older couples displayed little evidence of greater positivity and reduced negativity-especially women. During collaboration, older couples displayed a unique blend of warmth and control, suggesting a greater focus on emotional and social concerns during problem solving. (c) 2009 APA, all rights reserved.

  14. Couple Interaction and Predicting Vulnerability to Domestic Violence in Uttar Pradesh, India.

    Science.gov (United States)

    Singh, Brijesh P; Singh, Kaushalendra K; Singh, Neha

    2014-08-01

    Domestic violence, when conducted against women, is a type of gender-based violence that negatively impacts a woman's physical and psychological health, causing insecurity, lack of safety, and loss of health and self-worth. Domestic violence is an important consideration for sexual, reproductive, and child health, as it can affect contraceptive behaviors of couples as well as levels of infant mortality. In the present analysis, an attempt has been made to study the relationship between women's experience of domestic violence and couple interaction after controlling for certain socioeconomic and demographic variables using logistic regression. This study looks at data from the National Family Health Survey-III conducted from 2005 to 2006 in Uttar Pradesh, the most populous state of India. Findings reveal that 43% of women suffer from domestic violence in the society as a whole; however, if a couple makes joint decisions in household matters, the prevalence of domestic violence is observed to be 24% less. Education and occupation of women, standard of living, media exposure, and partner's alcoholic behaviors are also found to be possible predictors of domestic violence. © The Author(s) 2014.

  15. Coupled-oscillator theory of dispersion and Casimir-Polder interactions

    Energy Technology Data Exchange (ETDEWEB)

    Berman, P. R.; Ford, G. W. [Physics Department, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109-1040 (United States); Milonni, P. W. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States)

    2014-10-28

    We address the question of the applicability of the argument theorem (of complex variable theory) to the calculation of two distinct energies: (i) the first-order dispersion interaction energy of two separated oscillators, when one of the oscillators is excited initially and (ii) the Casimir-Polder interaction of a ground-state quantum oscillator near a perfectly conducting plane. We show that the argument theorem can be used to obtain the generally accepted equation for the first-order dispersion interaction energy, which is oscillatory and varies as the inverse power of the separation r of the oscillators for separations much greater than an optical wavelength. However, for such separations, the interaction energy cannot be transformed into an integral over the positive imaginary axis. If the argument theorem is used incorrectly to relate the interaction energy to an integral over the positive imaginary axis, the interaction energy is non-oscillatory and varies as r{sup −4}, a result found by several authors. Rather remarkably, this incorrect expression for the dispersion energy actually corresponds to the nonperturbative Casimir-Polder energy for a ground-state quantum oscillator near a perfectly conducting wall, as we show using the so-called “remarkable formula” for the free energy of an oscillator coupled to a heat bath [G. W. Ford, J. T. Lewis, and R. F. O’Connell, Phys. Rev. Lett. 55, 2273 (1985)]. A derivation of that formula from basic results of statistical mechanics and the independent oscillator model of a heat bath is presented.

  16. Coupled-oscillator theory of dispersion and Casimir-Polder interactions

    International Nuclear Information System (INIS)

    Berman, P. R.; Ford, G. W.; Milonni, P. W.

    2014-01-01

    We address the question of the applicability of the argument theorem (of complex variable theory) to the calculation of two distinct energies: (i) the first-order dispersion interaction energy of two separated oscillators, when one of the oscillators is excited initially and (ii) the Casimir-Polder interaction of a ground-state quantum oscillator near a perfectly conducting plane. We show that the argument theorem can be used to obtain the generally accepted equation for the first-order dispersion interaction energy, which is oscillatory and varies as the inverse power of the separation r of the oscillators for separations much greater than an optical wavelength. However, for such separations, the interaction energy cannot be transformed into an integral over the positive imaginary axis. If the argument theorem is used incorrectly to relate the interaction energy to an integral over the positive imaginary axis, the interaction energy is non-oscillatory and varies as r −4 , a result found by several authors. Rather remarkably, this incorrect expression for the dispersion energy actually corresponds to the nonperturbative Casimir-Polder energy for a ground-state quantum oscillator near a perfectly conducting wall, as we show using the so-called “remarkable formula” for the free energy of an oscillator coupled to a heat bath [G. W. Ford, J. T. Lewis, and R. F. O’Connell, Phys. Rev. Lett. 55, 2273 (1985)]. A derivation of that formula from basic results of statistical mechanics and the independent oscillator model of a heat bath is presented

  17. Coupled Fluid-Solid Interaction Under Shock Wave Loading: Part II - Dynamic Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Tipton, David Gregory [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Christon, Mark Allen [CTO Offce, Dassault Systµemes SIMULIA, Providence, RI (United States); Ingber, Marc Stuart [Univ. of New Mexico, Albuquerque, NM (United States). Department of Mechanical Engineering

    2009-07-01

    This article is the second of two that consider the treatment of fluid-solid interaction problems where the solid experiences wave loading and large bulk Lagrangian displacements. In part-I, we presented the formulation for the edge-based unstructured-grid Euler solver in the context of a discontinuous- Galerkin framework with the extensions used to treat internal fluid-solid interfaces. A super-sampled L2 projection was used to construct level-set data from the Lagrangian interface, and a narrow-band approach was used to identify and construct appropriate ghost data and boundary conditions at the fluid-solid interface. A series of benchmark problems were used to verify the treatment of the fluid-solid interface conditions with a static interface position. In this paper, we consider the treatment of dynamic interfaces and the associated large bulk Lagrangian displacements of the solid.We present the coupled dynamic fluid-solid system, and develop an explicit, monolithic treatment of the fully-coupled system. The conditions associated with moving interfaces and their implementation are discussed. A comparison of moving vs. fixed reference frames is used to verify the dynamic interface treatment. Lastly, a series of two and and three-dimensional projectile and shock-body interaction calculations are presented. Ultimately, the use of the Lagrangian interface position and a super-sampled projection for fast level-set construction, the narrow-band extraction of ghost data, and monolithic explicit solution algorithm has proved to be a computationally efficient means for treating shock induced fluid-solid interaction problems.

  18. Tetraquark candidate Zc(3900) from coupled-channel scattering - how to extract hadronic interactions? -

    Science.gov (United States)

    Ikeda, Yoichi

    2018-03-01

    We present recent progress of lattice QCD studies on hadronic interactions which play a crucial role to understand the properties of atomic nuclei and hadron resonances. There are two methods, the plateau method (or the direct method) and the HAL QCD method, to study the hadronic interactions. In the plateau method, the determination of a ground state energy from the temporal correlation functions of multi-hadron systems is a key to reliably extract the physical observables. It turns out that, due to the contamination of excited elastic scattering states nearby, one can easily be misled by a fake plateau into extracting the ground state energy. We introduce a consistency check (sanity check) which can rule out obviously false results obtained from a fake plateau, and find that none of the results obtained at the moment for two-baryon systems in the plateau method pass the test. On the other hand, the HAL QCD method is free from the fake-plateau problem. We investigate the systematic uncertainties of the HAL QCD method, which are found to be well controlled. On the basis of the HAL QCD method, the structure of the tetraquark candidate Zc(3900), which was experimentally reported in e+e- collisions, is studied by the s-wave two-meson coupled-channel scattering. The results show that the Zc(3900) is not a conventional resonance but a threshold cusp. A semi-phenomenological analysis with the coupled-channel interaction to the experimentally observed decay mode is also presented to confirm the conclusion.

  19. Conflict and Collaboration in Middle-Aged and Older Couples: I: Age Differences in Agency and Communion during Marital Interaction

    Science.gov (United States)

    Smith, Timothy W.; Berg, Cynthia A.; Florsheim, Paul; Uchino, Bert N.; Pearce, Gale; Hawkins, Melissa; Henry, Nancy J.M.; Beveridge, Ryan M.; Skinner, Michelle A.; Olsen-Cerny, Chrisanna

    2011-01-01

    Prior theory and research regarding age differences in marital interaction suggest that older couples display and experience more positivity and less negativity than middle-aged couples. However, studies of overt behavior in older couples are relatively rare and have emphasized disagreement, neglecting other important contexts for older couples such as collaboration during everyday problem solving. Further, the affiliation or communion dimension of social interaction (i.e., warmth vs. hostility) is commonly assessed, but not the control or agency dimension (e.g., dominance vs. submissiveness). The present study examined affect, cognitive appraisals, and overt behavior during disagreement (i.e., discussing a current conflict) and collaboration (i.e., planning errands) in 300 middle-aged and older married couples. Older couples reported less negative affect during disagreement and rated spouses as warmer than did middle-aged couples. However, these effects were eliminated when older couples’ greater marital satisfaction was controlled. For observed behavior, older couples displayed little evidence of greater positivity and reduced negativity – especially women. During collaboration, older couples displayed a unique blend of warmth and control, suggesting a greater focus on emotional and social concerns during problem solving. PMID:19485646

  20. Coupled-Cluster and Configuration-Interaction Calculations for Heavy Nuclei

    International Nuclear Information System (INIS)

    Horoi, M.; Gour, J. R.; Wloch, M.; Lodriguito, M. D.; Brown, B. A.; Piecuch, P.

    2007-01-01

    We compare coupled-cluster (CC) and configuration-interaction (CI) results for 56 Ni obtained in the pf-shell basis, focusing on practical CC approximations that can be applied to systems with dozens or hundreds of correlated fermions. The weight of the reference state and the strength of correlation effects are controlled by the gap between the f 7/2 orbit and the f 5/2 , p 3/2 , p 1/2 orbits. Independent of the gap, the CC method with 1p-1h and 2p-2h clusters and a noniterative treatment of 3p-3h clusters is as accurate as the more demanding CI approach truncated at the 4p-4h level

  1. Evolution of a G protein-coupled receptor response by mutations in regulatory network interactions

    DEFF Research Database (Denmark)

    Di Roberto, Raphaël B; Chang, Belinda; Trusina, Ala

    2016-01-01

    All cellular functions depend on the concerted action of multiple proteins organized in complex networks. To understand how selection acts on protein networks, we used the yeast mating receptor Ste2, a pheromone-activated G protein-coupled receptor, as a model system. In Saccharomyces cerevisiae......, Ste2 is a hub in a network of interactions controlling both signal transduction and signal suppression. Through laboratory evolution, we obtained 21 mutant receptors sensitive to the pheromone of a related yeast species and investigated the molecular mechanisms behind this newfound sensitivity. While...... demonstrate that a new receptor-ligand pair can evolve through network-altering mutations independently of receptor-ligand binding, and suggest a potential role for such mutations in disease....

  2. Particle-hole excitations in the interacting boson model; 4, the U(5)-SU(3) coupling

    CERN Document Server

    De Coster, C; Heyde, Kris L G; Jolie, J; Lehmann, H; Wood, J L

    1999-01-01

    In the extended interacting boson model (EIBM) both particle- and hole-like bosons are incorporated to encompass multi-particle-multi-hole excitations at and near to closed shells.We apply the group theoretical concepts of the EIBM to the particular case of two coexisting systems in the same nucleus exhibiting a U(5) (for the regular configurations) and an SU(3) symmetry (for the intruder configurations).Besides the description of ``global'' symmetry aspects in terms of I-spin , also the very specific local mixing effects characteristic for the U(5)-SU(3) symmetry coupling are studied.The model is applied to the Po isotopes and a comparison with a morerealistic calculation is made.

  3. ΛN-ΣN interaction with isobar coupling and six-quark resonances

    International Nuclear Information System (INIS)

    Greenberg, W.R.; Lomon, E.L.

    1993-01-01

    The long-range ΛN-ΣN interaction is modeled by a configuration-space meson-exchange potential matrix coupling to channels with Δ and Σ(1385) isobars. An inner boundary condition, based on R-matrix theory, replaces form factors for short-range effects and includes the effects of free quark configurations. An excellent fit is obtained to the available data, with only the energy-independent boundary conditions as free parameters. The effect of isobar thresholds is shown to be substantial in several partial waves and is crucial to the understanding of the higher-energy ΛN elastic scattering data. The positions and widths of [q(1s 1/2 )] 5 s(1s 1/2 ) quark exotics are predicted

  4. The influence of magnetostatic interactions in exchange-coupled composite particles

    DEFF Research Database (Denmark)

    Vokoun, D.; Beleggia, Marco; De Graef, M.

    2010-01-01

    Exchange-coupled composite (ECC) particles are the basic constituents of ECC magnetic recording media. We examine and compare two types of ECC particles: (i) core-shell structures, consisting of a hard-magnetic core and a coaxial soft-magnetic shell and (ii) conventional ECC particles, with a hard-magnetic...... core topped by a soft cylindrical element. The model we present describes the magnetic response of the two ECC particle types, taking into account all significant magnetic contributions to the energy landscape. Special emphasis is given to the magnetostatic (dipolar) interaction energy. We find...... that both the switching fields and the zero-field energy barrier depend strongly on the particle geometry. A comparison between the two types reveals that core-shell ECC particles are more effective in switching field reduction, while conventional ECC particles maintain a larger overall figure of merit....

  5. A density functional theory study of the magnetic exchange coupling in dinuclear manganese(II) inverse crown structures.

    Science.gov (United States)

    Vélez, Ederley; Alberola, Antonio; Polo, Víctor

    2009-12-17

    The magnetic exchange coupling constants between two Mn(II) centers for a set of five inverse crown structures have been investigated by means of a methodology based on broken-symmetry unrestricted density functional theory. These novel and highly unstable compounds present superexchange interactions between two Mn centers, each one with S = 5/2 through anionic "guests" such as oxygen, benzene, or hydrides or through the cationic ring formed by amide ligands and alkali metals (Na, Li). Magnetic exchange couplings calculated at B3LYP/6-31G(d,p) level yield strong antiferromagnetic couplings for compounds linked via an oxygen atom or hydride and very small antiferromagnetic couplings for those linked via a benzene molecule, deprotonated in either 1,4- or 1,3- positions. Analysis of the magnetic orbitals and spin polarization maps provide an understanding of the exchange mechanism between the Mn centers. The dependence of J with respect to 10 different density functional theory potentials employed and the basis set has been analyzed.

  6. Electrically and mechanically induced macroscopic body couple, a newly recognized phenomenon of electromechanical interaction

    International Nuclear Information System (INIS)

    Chen, P.J.

    1986-01-01

    Microscopically, when the molecules of certain materials are under the influence of external stimuli such as mechanical and electrical forces, several processes can happen. In particular, the centers of charge of the positive and negative ions of a molecule may displace with respect to each other. This notion leads to the macroscopic concept of polarization which has been exploited in the classical studies of piezoelectric and ferroelectric materials. In addition, the ions of the molecule may also rotate angularly relative to one another. Here an entirely new macroscopic concept of body couple which differs from the classical concept is introduced. It is shown that the simplest representations of the proposed constitutive relations lead to an equation within the context of the classical bending theory of thin plates whose solution is in remarkable agreement with recent experimental results concerning the bending of thin virgin ferroelectric ceramic discs under the action of small d.c. voltages. These experimental results cannot be explained by the classical notion of polarization. Therefore, the concept of macroscopic body couple introduced here is a fundamental feature which must be taken into account in the considerations of electromechanical interactions

  7. Resonant atom-field interaction in large-size coupled-cavity arrays

    International Nuclear Information System (INIS)

    Ciccarello, Francesco

    2011-01-01

    We consider an array of coupled cavities with staggered intercavity couplings, where each cavity mode interacts with an atom. In contrast to large-size arrays with uniform hopping rates where the atomic dynamics is known to be frozen in the strong-hopping regime, we show that resonant atom-field dynamics with significant energy exchange can occur in the case of staggered hopping rates even in the thermodynamic limit. This effect arises from the joint emergence of an energy gap in the free photonic dispersion relation and a discrete frequency at the gap's center. The latter corresponds to a bound normal mode stemming solely from the finiteness of the array length. Depending on which cavity is excited, either the atomic dynamics is frozen or a Jaynes-Cummings-like energy exchange is triggered between the bound photonic mode and its atomic analog. As these phenomena are effective with any number of cavities, they are prone to be experimentally observed even in small-size arrays.

  8. Laser-material interactions: A study of laser energy coupling with solids

    Energy Technology Data Exchange (ETDEWEB)

    Shannon, Mark Alan [Univ. of California, Berkeley, CA (United States)

    1993-11-01

    This study of laser-light interactions with solid materials ranges from low-temperature heating to explosive, plasma-forming reactions. Contained are four works concerning laser-energy coupling: laser (i) heating and (ii) melting monitored using a mirage effect technique, (iii) the mechanical stress-power generated during high-powered laser ablation, and (iv) plasma-shielding. First, a photothermal deflection (PTD) technique is presented for monitoring heat transfer during modulated laser heating of opaque solids that have not undergone phase-change. Of main interest is the physical significance of the shape, magnitude, and phase for the temporal profile of the deflection signal. Considered are the effects that thermophysical properties, boundary conditions, and geometry of the target and optical probe-beam have on the deflection response. PTD is shown to monitor spatial and temporal changes in heat flux leaving the surface due to changes in laser energy coupling. The PTD technique is then extended to detect phase-change at the surface of a solid target. Experimental data shows the onset of melt for indium and tin targets. The conditions for which melt can be detected by PTD is analyzed in terms of geometry, incident power and pulse length, and thermophysical properties of the target and surroundings. Next, monitoring high-powered laser ablation of materials with stress-power is introduced. The motivation for considering stress-power is given, followed by a theoretical discussion of stress-power and how it is determined experimentally. Experiments are presented for the ablation of aluminum targets as a function of energy and intensity. The stress-power response is analyzed for its physical significance. Lastly, the influence of plasma-shielding during high-powered pulsed laser-material interactions is considered. Crater size, emission, and stress-power are measured to determine the role that the gas medium and laser pulse length have on plasma shielding.

  9. Laser-material interactions: A study of laser energy coupling with solids

    International Nuclear Information System (INIS)

    Shannon, M.A.; California Univ., Berkeley, CA

    1993-11-01

    This study of laser-light interactions with solid materials ranges from low-temperature heating to explosive, plasma-forming reactions. Contained are four works concerning laser-energy coupling: laser (i) heating and (ii) melting monitored using a mirage effect technique, (iii) the mechanical stress-power generated during high-powered laser ablation, and (iv) plasma-shielding. First, a photothermal deflection (PTD) technique is presented for monitoring heat transfer during modulated laser heating of opaque solids that have not undergone phase-change. Of main interest is the physical significance of the shape, magnitude, and phase for the temporal profile of the deflection signal. Considered are the effects that thermophysical properties, boundary conditions, and geometry of the target and optical probe-beam have on the deflection response. PTD is shown to monitor spatial and temporal changes in heat flux leaving the surface due to changes in laser energy coupling. The PTD technique is then extended to detect phase-change at the surface of a solid target. Experimental data shows the onset of melt for indium and tin targets. The conditions for which melt can be detected by PTD is analyzed in terms of geometry, incident power and pulse length, and thermophysical properties of the target and surroundings. Next, monitoring high-powered laser ablation of materials with stress-power is introduced. The motivation for considering stress-power is given, followed by a theoretical discussion of stress-power and how it is determined experimentally. Experiments are presented for the ablation of aluminum targets as a function of energy and intensity. The stress-power response is analyzed for its physical significance. Lastly, the influence of plasma-shielding during high-powered pulsed laser-material interactions is considered. Crater size, emission, and stress-power are measured to determine the role that the gas medium and laser pulse length have on plasma shielding

  10. Yukawa multipole electrostatics and nontrivial coupling between electrostatic and dispersion interactions in electrolytes

    International Nuclear Information System (INIS)

    Kjellander, Roland; Ramirez, Rosa

    2008-01-01

    An exact treatment of screened electrostatics in electrolyte solutions is presented. In electrolytes the anisotropy of the exponentially decaying electrostatic potential from a molecule extends to the far field region. The full directional dependence of the electrostatic potential from a charged or uncharged molecule remains in the longest range tail (i.e. from all multipole moments). In particular, the range of the potential from an ion and that from an electroneutral polar particle is generally exactly the same. This is in contrast to the case in vacuum or pure polar liquids, where the potential from a single charge is longer ranged than that from a dipole, which is, itself, longer ranged than the one from a quadrupole etc. The orientational dependence of the exponentially screened electrostatic interaction between two molecules in electrolytes is therefore rather complex even at long distances. These facts are formalized in Yukawa multipole expansions of the electrostatic potential and the pair interaction free energy based on the Yukawa function family exp(-κr)/r m , where r is the distance, κ is a decay parameter and m is a positive integer. The expansion is formally exact for electrolytes with molecular solvent and in the primitive model, provided the non-Coulombic interactions between the particles are sufficiently short ranged. The results can also be applied in the Poisson-Boltzmann approximation. Differences and similarities to the ordinary multipole expansion of electrostatics are pointed out. On the other hand, when the non-Coulombic interactions between the constituent particles of the electrolyte solution contain a dispersion 1/r 6 potential, the electrostatic potential from a molecule decays like a power law for long distances rather than as a Yukawa function. This is due to nontrivial coupling between the electrostatic and dispersion interactions. There remains an exponentially decaying component in the electrostatic potential, but it becomes

  11. Fluid-structure interaction including volumetric coupling with homogenised subdomains for modeling respiratory mechanics.

    Science.gov (United States)

    Yoshihara, Lena; Roth, Christian J; Wall, Wolfgang A

    2017-04-01

    In this article, a novel approach is presented for combining standard fluid-structure interaction with additional volumetric constraints to model fluid flow into and from homogenised solid domains. The proposed algorithm is particularly interesting for investigations in the field of respiratory mechanics as it enables the mutual coupling of airflow in the conducting part and local tissue deformation in the respiratory part of the lung by means of a volume constraint. In combination with a classical monolithic fluid-structure interaction approach, a comprehensive model of the human lung can be established that will be useful to gain new insights into respiratory mechanics in health and disease. To illustrate the validity and versatility of the novel approach, three numerical examples including a patient-specific lung model are presented. The proposed algorithm proves its capability of computing clinically relevant airflow distribution and tissue strain data at a level of detail that is not yet achievable, neither with current imaging techniques nor with existing computational models. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Directionality of coupling of physiological subsystems: age-related changes of cardiorespiratory interaction during different sleep stages in babies.

    Science.gov (United States)

    Mrowka, Ralf; Cimponeriu, Laura; Patzak, Andreas; Rosenblum, Michael G

    2003-12-01

    Activity of many physiological subsystems has a well-expressed rhythmic character. Often, a dependency between physiological rhythms is established due to interaction between the corresponding subsystems. Traditional methods of data analysis allow one to quantify the strength of interaction but not the causal interrelation that is indispensable for understanding the mechanisms of interaction. Here we present a recently developed method for quantification of coupling direction and apply it to an important problem. Namely, we study the mutual influence of respiratory and cardiovascular rhythms in healthy newborns within the first 6 mo of life in quiet and active sleep. We find an age-related change of the coupling direction: the interaction is nearly symmetric during the first days and becomes practically unidirectional (from respiration to heart rhythm) at the age of 6 mo. Next, we show that the direction of interaction is mainly determined by respiratory frequency. If the latter is less than approximately 0.6 Hz, the interaction occurs dominantly from respiration to heart. With higher respiratory frequencies that only occur at very young ages, the dominating direction is less pronounced or even abolished. The observed dependencies are not related to sleep stage, suggesting that the coupling direction is determined by system-inherent dynamical processes, rather than by functional modulations. The directional analysis may be applied to other interacting narrow band oscillatory systems, e.g., in the central nervous system. Thus it is an important step forward in revealing and understanding causal mechanisms of interactions.

  13. Coupling R and PHREEQC: an interactive and extensible environment for efficient programming of geochemical models

    Science.gov (United States)

    De Lucia, Marco; Kühn, Michael

    2013-04-01

    PHREEQC [1] is a widely used non-interactive open source software for speciation, batch-reactions, one-dimensional transport, and inverse geochemical caclulations. It represents the tool of choice for many researchers and practicioners for a broad set of geochemical problems, underground CO2 storage among others. Its open source nature, the flexibility to program arbitrary kinetic laws for the chemical reactions, as well as a thorough implementation of the Pitzer formalism explain its success and longevity. However, its non-interactive architecture make it cumbersome to couple PHREEQC to transport programs to achieve reactive transport simulations [2], but also to overcome the limitations of PHREEQC itself regarding the setup of large numbers of simulations - for example exploring wide ranges of conditions - and the graphical evaluation of the results. This has been the main motivation leading to the development of an interface with the high level language and environment for statistical computing and graphics GNU R [3]. The interface consists of minor modifications in PHREEQC's C source code, only affecting data I/O, plus on the R side a bunch of helper functions used to setup the simulations - basically automated manipulation of PHREEQC's input files, which are text files - and to collect and visualize the results. The most relevant subset of PHREEQC's capabilities and features are fully usable through the interface. Illustratory examples for the utility of this programmable interface were given in the framework of the research project this developement originated from: CLEAN [4], a project investigating the feasibility of enhanced gas recovery combined with CO2 storage. This interface allowed us to successfully and easily manipulate, compare and refit chemical databases, perform sensitivity analysis by combinatory variations of parameters, and all that in an environment which is both scriptable and interactive, with all results directly available for further

  14. Numerical simulation of the solitary wave interacting with an elastic structure using MPS-FEM coupled method

    Science.gov (United States)

    Rao, Chengping; Zhang, Youlin; Wan, Decheng

    2017-12-01

    Fluid-Structure Interaction (FSI) caused by fluid impacting onto a flexible structure commonly occurs in naval architecture and ocean engineering. Research on the problem of wave-structure interaction is important to ensure the safety of offshore structures. This paper presents the Moving Particle Semi-implicit and Finite Element Coupled Method (MPS-FEM) to simulate FSI problems. The Moving Particle Semi-implicit (MPS) method is used to calculate the fluid domain, while the Finite Element Method (FEM) is used to address the structure domain. The scheme for the coupling of MPS and FEM is introduced first. Then, numerical validation and convergent study are performed to verify the accuracy of the solver for solitary wave generation and FSI problems. The interaction between the solitary wave and an elastic structure is investigated by using the MPS-FEM coupled method.

  15. Characterization of G-protein coupled receptor kinase interaction with the neurokinin-1 receptor using bioluminescence resonance energy transfer

    DEFF Research Database (Denmark)

    Jorgensen, Rasmus; Holliday, Nicholas D; Hansen, Jakob L

    2007-01-01

    To analyze the interaction between the neurokinin-1 (NK-1) receptor and G-protein coupled receptor kinases (GRKs), we performed bioluminescence resonance energy transfer(2) (BRET(2)) measurements between the family A NK-1 receptor and GRK2 and GRK5 as well as their respective kinase-inactive muta......To analyze the interaction between the neurokinin-1 (NK-1) receptor and G-protein coupled receptor kinases (GRKs), we performed bioluminescence resonance energy transfer(2) (BRET(2)) measurements between the family A NK-1 receptor and GRK2 and GRK5 as well as their respective kinase...

  16. Direction of coupling from phases of interacting oscillators: An information-theoretic approach

    Science.gov (United States)

    Paluš, Milan; Stefanovska, Aneta

    2003-05-01

    A directionality index based on conditional mutual information is proposed for application to the instantaneous phases of weakly coupled oscillators. Its abilities to distinguish unidirectional from bidirectional coupling, as well as to reveal and quantify asymmetry in bidirectional coupling, are demonstrated using numerical examples of quasiperiodic, chaotic, and noisy oscillators, as well as real human cardiorespiratory data.

  17. Results of an interactively coupled atmospheric chemistry - general circulation model. Comparison with observations

    Energy Technology Data Exchange (ETDEWEB)

    Hein, R.; Dameris, M.; Schnadt, C. [and others

    2000-01-01

    An interactively coupled climate-chemistry model which enables a simultaneous treatment of meteorology and atmospheric chemistry and their feedbacks is presented. This is the first model, which interactively combines a general circulation model based on primitive equations with a rather complex model of stratospheric and tropospheric chemistry, and which is computational efficient enough to allow long-term integrations with currently available computer resources. The applied model version extends from the Earth's surface up to 10 hPa with a relatively high number (39) of vertical levels. We present the results of a present-day (1990) simulation and compare it to available observations. We focus on stratospheric dynamics and chemistry relevant to describe the stratospheric ozone layer. The current model version ECHAM4.L39(DLR)/CHEM can realistically reproduce stratospheric dynamics in the Arctic vortex region, including stratospheric warming events. This constitutes a major improvement compared to formerly applied model versions. However, apparent shortcomings in Antarctic circulation and temperatures persist. The seasonal and interannual variability of the ozone layer is simulated in accordance with observations. Activation and deactivation of chlorine in the polar stratospheric vortices and their interhemispheric differences are reproduced. The consideration of the chemistry feedback on dynamics results in an improved representation of the spatial distribution of stratospheric water vapor concentrations, i.e., the simulated meriodional water vapor gradient in the stratosphere is realistic. The present model version constitutes a powerful tool to investigate, for instance, the combined direct and indirect effects of anthropogenic trace gas emissions, and the future evolution of the ozone layer. (orig.)

  18. Electron correlation in the interacting quantum atoms partition via coupled-cluster lagrangian densities.

    Science.gov (United States)

    Holguín-Gallego, Fernando José; Chávez-Calvillo, Rodrigo; García-Revilla, Marco; Francisco, Evelio; Pendás, Ángel Martín; Rocha-Rinza, Tomás

    2016-07-15

    The electronic energy partition established by the Interacting Quantum Atoms (IQA) approach is an important method of wavefunction analyses which has yielded valuable insights about different phenomena in physical chemistry. Most of the IQA applications have relied upon approximations, which do not include either dynamical correlation (DC) such as Hartree-Fock (HF) or external DC like CASSCF theory. Recently, DC was included in the IQA method by means of HF/Coupled-Cluster (CC) transition densities (Chávez-Calvillo et al., Comput. Theory Chem. 2015, 1053, 90). Despite the potential utility of this approach, it has a few drawbacks, for example, it is not consistent with the calculation of CC properties different from the total electronic energy. To improve this situation, we have implemented the IQA energy partition based on CC Lagrangian one- and two-electron orbital density matrices. The development presented in this article is tested and illustrated with the H2 , LiH, H2 O, H2 S, N2 , and CO molecules for which the IQA results obtained under the consideration of (i) the CC Lagrangian, (ii) HF/CC transition densities, and (iii) HF are critically analyzed and compared. Additionally, the effect of the DC in the different components of the electronic energy in the formation of the T-shaped (H2 )2 van der Waals cluster and the bimolecular nucleophilic substitution between F(-) and CH3 F is examined. We anticipate that the approach put forward in this article will provide new understandings on subjects in physical chemistry wherein DC plays a crucial role like molecular interactions along with chemical bonding and reactivity. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Detecting the multi-spin interaction of an XY spin chain by the geometric phase of a coupled qubit

    International Nuclear Information System (INIS)

    Zhang, Xiu-xing; Zhang, Ai-ping; Li, Fu-li

    2012-01-01

    We investigate geometric phase (GP) of a qubit symmetrically coupled to a XY spin chain with three-spin interaction in a transverse magnetic field. An analytical expression for the GP is found in the weak coupling limit. It is shown that the GP displays a sharp peak or dip around the quantum phase transition point of the spin chain. Without the three-spin interaction, the GP has a peak or dip around the critical point λ=1. If the three-spin interaction exists, the peak or dip position is obviously shifted away from the original position. This result reveals that the GP may be taken as an observable to detect both the existence and strength of multi-spin interaction in a spin chain. -- Highlights: ► Analytical expression for geometric phase (GP) of a qubit coupled to a spin chain is obtained. ► Relation between GP and multi-spin interaction is investigated. ► Detection of multi-spin interaction by means of GP is proposed.

  20. Entanglement Criteria of Two Two-Level Atoms Interacting with Two Coupled Modes

    Science.gov (United States)

    Baghshahi, Hamid Reza; Tavassoly, Mohammad Kazem; Faghihi, Mohammad Javad

    2015-08-01

    In this paper, we study the interaction between two two-level atoms and two coupled modes of a quantized radiation field in the form of parametric frequency converter injecting within an optical cavity enclosed by a medium with Kerr nonlinearity. It is demonstrated that, by applying the Bogoliubov-Valatin canonical transformation, the introduced model is reduced to a well-known form of the generalized Jaynes-Cummings model. Then, under particular initial conditions for the atoms (in a coherent superposition of its ground and upper states) and the fields (in a standard coherent state) which may be prepared, the time evolution of state vector of the entire system is analytically evaluated. In order to understand the degree of entanglement between subsystems (atom-field and atom-atom), the dynamics of entanglement through different measures, namely, von Neumann reduced entropy, concurrence and negativity is evaluated. In each case, the effects of Kerr nonlinearity and detuning parameter on the above measures are numerically analyzed, in detail. It is illustrated that the amount of entanglement can be tuned by choosing the evolved parameters, appropriately.

  1. Determination of Oxidized Phosphatidylcholines by Hydrophilic Interaction Liquid Chromatography Coupled to Fourier Transform Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Pia Sala

    2015-04-01

    Full Text Available A novel liquid chromatography-mass spectrometry (LC-MS approach for analysis of oxidized phosphatidylcholines by an Orbitrap Fourier Transform mass spectrometer in positive electrospray ionization (ESI coupled to hydrophilic interaction liquid chromatography (HILIC was developed. This method depends on three selectivity criteria for separation and identification: retention time, exact mass at a resolution of 100,000 and collision induced dissociation (CID fragment spectra in a linear ion trap. The process of chromatography development showed the best separation properties with a silica-based Kinetex column. This type of chromatography was able to separate all major lipid classes expected in mammalian samples, yielding increased sensitivity of oxidized phosphatidylcholines over reversed phase chromatography. Identification of molecular species was achieved by exact mass on intact molecular ions and CID tandem mass spectra containing characteristic fragments. Due to a lack of commercially available standards, method development was performed with copper induced oxidation products of palmitoyl-arachidonoyl-phosphatidylcholine, which resulted in a plethora of lipid species oxidized at the arachidonoyl moiety. Validation of the method was done with copper oxidized human low-density lipoprotein (LDL prepared by ultracentrifugation. In these LDL samples we could identify 46 oxidized molecular phosphatidylcholine species out of 99 possible candidates.

  2. Coupling properties and edge plasma interaction characteristics of the new Tore Supra lower hybrid antenna

    International Nuclear Information System (INIS)

    Bibet, Ph.; Fuchs, V.; Mailloux, J.

    1999-01-01

    A significant part of the non-inductive in Tore Supra will be driven by a new launcher, to be installed in September 1999. The antenna phase 2 is made of 6 rows with 48 active waveguides and 9 passive ones in each. Passive waveguides are inserted at every 6. active one. This grill has been designed in the frame of the CIEL project. It will inject 4 MW at 3.7 GHz at a safe power density of 25 MW/m 2 for a pulse length of 1000 s. The radiated spectrum peaks at N // = 2.03 with a possible variation of ± 0.35 and a FWHM of 0.35. In order to prepare for operation with this grill, the coupling properties and the power directivity of the radiated spectra have been studied as a function of: the electron density and electron density gradient ; the feeding phase shift between the 8 antenna modules; the geometry of the antenna. Furthermore, the interaction of plasma edge electrons with the antenna is analysed and a comparison with the previous Tore Supra antenna is made. This is done for a range of plasma parameters and feeding phase. (authors)

  3. Tropical-extratropical climate interaction as revealed in idealized coupled climate model experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Haijun [Peking University, Department of Atmospheric Science and Laboratory for Severe Storm and Flood Disasters, School of Physics, Beijing (China); Liu, Zhengyu [University of Wisconsin-Madison, Center for Climatic Research and Department of the Atmospheric and Oceanic Sciences, Madison, WI (United States)

    2005-06-01

    Tropical-extratropical climate interactions are studied by idealized experiments with a prescribed 2 C SST anomaly at different latitude bands in a coupled climate model. Instead of focusing on intrinsic climate variability, this work investigates the mean climate adjustment to remote external forcing. The extratropical impact on tropical climate can be as strong as the tropical impact on extratropical climate, with the remote sea surface temperature (SST) response being about half the magnitude of the imposed SST change in the forcing region. The equatorward impact of extratropical climate is accomplished by both the atmospheric bridge and the oceanic tunnel. About two-thirds of the tropical SST change comes from the atmospheric bridge, while the remaining one-third comes from the oceanic tunnel. The equatorial SST increase is first driven by the reduced latent heat flux and the weakened poleward surface Ekman transport, and then enhanced by the decrease in subtropical cells' strength and the equatorward subduction of warm anomalies. In contrast, the poleward impact of tropical climate is accomplished mainly by the atmospheric bridge, which is responsible for extratropical temperature changes in both the surface and subsurface. Sensitivity experiments also show the dominant role of the Southern Hemisphere oceans in the tropical climate change. (orig.)

  4. Identification of coupling DNA motif pairs on long-range chromatin interactions in human K562 cells

    KAUST Repository

    Wong, Ka-Chun; Li, Yue; Peng, Chengbin

    2015-01-01

    Motivation: The protein-DNA interactions between transcription factors (TFs) and transcription factor binding sites (TFBSs, also known as DNA motifs) are critical activities in gene transcription. The identification of the DNA motifs is a vital task for downstream analysis. Unfortunately, the long-range coupling information between different DNA motifs is still lacking. To fill the void, as the first-of-its-kind study, we have identified the coupling DNA motif pairs on long-range chromatin interactions in human. Results: The coupling DNA motif pairs exhibit substantially higher DNase accessibility than the background sequences. Half of the DNA motifs involved are matched to the existing motif databases, although nearly all of them are enriched with at least one gene ontology term. Their motif instances are also found statistically enriched on the promoter and enhancer regions. Especially, we introduce a novel measurement called motif pairing multiplicity which is defined as the number of motifs that are paired with a given motif on chromatin interactions. Interestingly, we observe that motif pairing multiplicity is linked to several characteristics such as regulatory region type, motif sequence degeneracy, DNase accessibility and pairing genomic distance. Taken into account together, we believe the coupling DNA motif pairs identified in this study can shed lights on the gene transcription mechanism under long-range chromatin interactions. © The Author 2015. Published by Oxford University Press.

  5. Interaction between G Protein-Coupled Receptor 143 and Tyrosinase: Implications for Understanding Ocular Albinism Type 1.

    Science.gov (United States)

    De Filippo, Elisabetta; Schiedel, Anke C; Manga, Prashiela

    2017-02-01

    Developmental eye defects in X-linked ocular albinism type 1 are caused by G-protein coupled receptor 143 (GPR143) mutations. Mutations result in dysfunctional melanosome biogenesis and macromelanosome formation in pigment cells, including melanocytes and retinal pigment epithelium. GPR143, primarily expressed in pigment cells, localizes exclusively to endolysosomal and melanosomal membranes unlike most G protein-coupled receptors, which localize to the plasma membrane. There is some debate regarding GPR143 function and elucidating the role of this receptor may be instrumental for understanding neurogenesis during eye development and for devising therapies for ocular albinism type I. Many G protein-coupled receptors require association with other proteins to function. These G protein-coupled receptor-interacting proteins also facilitate fine-tuning of receptor activity and tissue specificity. We therefore investigated potential GPR143 interaction partners, with a focus on the melanogenic enzyme tyrosinase. GPR143 coimmunoprecipitated with tyrosinase, while confocal microscopy demonstrated colocalization of the proteins. Furthermore, tyrosinase localized to the plasma membrane when coexpressed with a GPR143 trafficking mutant. The physical interaction between the proteins was confirmed using fluorescence resonance energy transfer. This interaction may be required in order for GPR143 to function as a monitor of melanosome maturation. Identifying tyrosinase as a potential GPR143 binding protein opens new avenues for investigating the mechanisms that regulate pigmentation and neurogenesis. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Identification of coupling DNA motif pairs on long-range chromatin interactions in human K562 cells

    KAUST Repository

    Wong, Ka-Chun

    2015-09-27

    Motivation: The protein-DNA interactions between transcription factors (TFs) and transcription factor binding sites (TFBSs, also known as DNA motifs) are critical activities in gene transcription. The identification of the DNA motifs is a vital task for downstream analysis. Unfortunately, the long-range coupling information between different DNA motifs is still lacking. To fill the void, as the first-of-its-kind study, we have identified the coupling DNA motif pairs on long-range chromatin interactions in human. Results: The coupling DNA motif pairs exhibit substantially higher DNase accessibility than the background sequences. Half of the DNA motifs involved are matched to the existing motif databases, although nearly all of them are enriched with at least one gene ontology term. Their motif instances are also found statistically enriched on the promoter and enhancer regions. Especially, we introduce a novel measurement called motif pairing multiplicity which is defined as the number of motifs that are paired with a given motif on chromatin interactions. Interestingly, we observe that motif pairing multiplicity is linked to several characteristics such as regulatory region type, motif sequence degeneracy, DNase accessibility and pairing genomic distance. Taken into account together, we believe the coupling DNA motif pairs identified in this study can shed lights on the gene transcription mechanism under long-range chromatin interactions. © The Author 2015. Published by Oxford University Press.

  7. Integrated modeling of land-use change: the role of coupling, interactions and feedbacks between the human and Earth systems

    Science.gov (United States)

    Monier, E.; Kicklighter, D. W.; Ejaz, Q.; Winchester, N.; Paltsev, S.; Reilly, J. M.

    2016-12-01

    Land-use change integrates a large number of components of the human and Earth systems, including climate, energy, water, and land. These complex coupling elements, interactions and feedbacks take place on a variety of space and time scales, thus increasing the complexity of land-use change modeling frameworks. In this study, we aim to identify which coupling elements, interactions and feedbacks are important for modeling land-use change, both at the global and regional level. First, we review the existing land-use change modeling framework used to develop land-use change projections for the Representative Concentration Pathways (RCP) scenarios. In such framework, land-use change is simulated by Integrated Assessment Models (IAMs) and mainly influenced by economic, energy, demographic and policy drivers. IAMs focus on representing the demand for agriculture and forestry goods (crops for food and bioenergy, forest products for construction and bioenergy), the interactions with other sectors of the economy and trade between various regions of the world. Then, we investigate how important various coupling elements and feedbacks with the Earth system are for projections of land-use change at the global and regional level. We focus on the following: i) the climate impacts on land productivity and greenhouse gas emissions, which requires climate change information and coupling to a terrestrial ecosystem model/crop model; ii) the climate and economic impacts on irrigation availability, which requires coupling the LUC modeling framework to a water resources management model and disaggregating rainfed and irrigated croplands; iii) the feedback of land-use change on the global and regional climate system through land-use change emissions and changes in the surface albedo and hydrology, which requires coupling to an Earth system model. Finally, we conclude our study by highlighting the current lack of clarity in how various components of the human and Earth systems are

  8. Coupling of tt̄ and γγ with a strongly interacting Electroweak Symmetry Breaking Sector

    Directory of Open Access Journals (Sweden)

    Delgado Rafael L.

    2017-01-01

    Full Text Available We report the coupling of an external γγ or tt̄ state to a strongly interacting EWSBS satisfying unitarity. We exploit perturbation theory for those coupling of the external state, whereas the EWSBS is taken as strongly interacting. We use a modified version of the IAM unitarization procedure to model such a strongly interacting regime. The matrix elements VLVL → VLVL, VLVL ↔ hh, hh → hh, VLVL ↔ {γγ, tt̄}, hh ↔ {γγ, tt̄} are all computed to NLO in perturbation theory with the Nonlinear Effective Field Theory of the EWSBS, within the Equivalence Theorem. This allows us to describe resonances of the electroweak sector that may be found at the LHC and their effect on other channels such as γγ or tt̄ where they may be discovered.

  9. Complex Interaction Mechanisms between Dislocations and Point Defects Studied in Pure Aluminium by a Two-Wave Acoustic Coupling Technique

    Science.gov (United States)

    Bremnes, O.; Progin, O.; Gremaud, G.; Benoit, W.

    1997-04-01

    Ultrasonic experiments using a two-wave coupling technique were performed on 99.999% pure Al in order to study the interaction mechanisms occurring between dislocations and point defects. The coupling technique consists in measuring the attenuation of ultrasonic waves during low-frequency stress cycles (t). One obtains closed curves () called signatures whose shape and evolution are characteristic of the interaction mechanism controlling the low-frequency dislocation motion. The signatures observed were attributed to the interaction of the dislocations with extrinsic point defects. A new interpretation of the evolution of the signatures measured below 200 K with respect to temperature and stress frequency had to be established: they are linked to depinning of immobile point defects, whereas a thermally activated depinning mechanism does not fit the observations. The signatures measured between 200 and 370 K were interpreted as dragging and depinning of extrinsic point defects which are increasingly mobile with temperature.

  10. Direction of Coupling from Phases of Interacting Oscillators: A Permutation Information Approach

    Science.gov (United States)

    Bahraminasab, A.; Ghasemi, F.; Stefanovska, A.; McClintock, P. V. E.; Kantz, H.

    2008-02-01

    We introduce a directionality index for a time series based on a comparison of neighboring values. It can distinguish unidirectional from bidirectional coupling, as well as reveal and quantify asymmetry in bidirectional coupling. It is tested on a numerical model of coupled van der Pol oscillators, and applied to cardiorespiratory data from healthy subjects. There is no need for preprocessing and fine-tuning the parameters, which makes the method very simple, computationally fast and robust.

  11. Results of an interactively coupled atmospheric chemistry – general circulation model: Comparison with observations

    Directory of Open Access Journals (Sweden)

    R. Hein

    Full Text Available The coupled climate-chemistry model ECHAM4.L39(DLR/CHEM is presented which enables a simultaneous treatment of meteorology and atmospheric chemistry and their feedbacks. This is the first model which interactively combines a general circulation model with a chemical model, employing most of the important reactions and species necessary to describe the stratospheric and upper tropospheric ozone chemistry, and which is computationally fast enough to allow long-term integrations with currently available computer resources. This is possible as the model time-step used for the chemistry can be chosen as large as the integration time-step for the dynamics. Vertically the atmosphere is discretized by 39 levels from the surface up to the top layer which is centred at 10 hPa, with a relatively high vertical resolution of approximately 700 m near the extra-tropical tropopause. We present the results of a control simulation representing recent conditions (1990 and compare it to available observations. The focus is on investigations of stratospheric dynamics and chemistry relevant to describe the stratospheric ozone layer. ECHAM4.L39(DLR/CHEM reproduces main features of stratospheric dynamics in the arctic vortex region, including stratospheric warming events. This constitutes a major improvement compared to earlier model versions. However, apparent shortcomings in Antarctic circulation and temperatures persist. The seasonal and interannual variability of the ozone layer is simulated in accordance with observations. Activation and deactivation of chlorine in the polar stratospheric vortices and their inter-hemispheric differences are reproduced. Considering methane oxidation as part of the dynamic-chemistry feedback results in an improved representation of the spatial distribution of stratospheric water vapour concentrations. The current model constitutes a powerful tool to investigate, for instance, the combined direct and indirect effects of anthropogenic

  12. Theory of one-dimensional hopping motion of a heavy particle interacting with phonons by different couplings

    Science.gov (United States)

    Itai, K.

    1987-02-01

    Two models which describe one-dimensional hopping motion of a heavy particle interacting with phonons are discussed. Model A corresponds to hopping in 1D metals or to the polaron problem. In model B the momentum dependence of the particle-phonon coupling is proportional to k-1/2. The scaling equations show that only in model B does localization occur for a coupling larger than a critical value. In the localization region this model shows close analogy to the Caldeira-Leggett model for macroscopic quantum tunneling.

  13. Effect of interactions for one-dimensional asymmetric exclusion processes under periodic and bath-adapted coupling environment

    Science.gov (United States)

    Midha, Tripti; Kolomeisky, Anatoly B.; Gupta, Arvind Kumar

    2018-04-01

    Stimulated by the effect of the nearest neighbor interactions in vehicular traffic and motor proteins, we study a 1D driven lattice gas model, in which the nearest neighbor particle interactions are taken in accordance with the thermodynamic concepts. The non-equilibrium steady-state properties of the system are analyzed under both open and periodic boundary conditions using a combination of cluster mean-field analysis and Monte Carlo simulations. Interestingly, the fundamental diagram of current versus density shows a complex behavior with a unimodal dependence for attractions and weak repulsions that turns into the bimodal behavior for stronger repulsive interactions. Specific details of system-reservoir coupling for the open system have a strong effect on the stationary phases. We produce the steady-state phase diagrams for the bulk-adapted coupling to the reservoir using the minimum and maximum current principles. The strength and nature of interaction energy has a striking influence on the number of stationary phases. We observe that interactions lead to correlations having a strong impact on the system dynamical properties. The correlation between any two sites decays exponentially as the distance between the sites increases. Moreover, they are found to be short-range for repulsions and long-range for attractions. Our results also suggest that repulsions and attractions asymmetrically modify the dynamics of interacting particles in exclusion processes.

  14. Crystal Structure and Magnetic Behavior of Two New Dinuclear Carbonato-Bridged Copper(II) Compounds. Superexchange Pathway for the Different Coordination Modes of the Carbonato Bridge in Polynuclear Copper(II) Compounds.

    Science.gov (United States)

    Escuer, Albert; Mautner, Franz A.; Peñalba, Evaristo; Vicente, Ramon

    1998-08-24

    Four new &mgr;-CO(3)(2-) copper(II) complexes with different coordination modes for the carbonato bridge have been obtained by fixation of atmospheric CO(2): {(&mgr;(3)-CO(3))[Cu(3)(ClO(4))(3)(Et(3)dien)(3)]}(ClO(4)) (1), Et(3)dien = N,N',N"-triethylbis(2-aminoethane)amine; {(&mgr;-CO(3))[Cu(2)(H(2)O)(Et(4)dien)(2)]}(ClO(4))(2).H(2)O (2), Et(4)dien = N,N,N",N"-tetraethyl-bis(2-aminoethane)amine; {(&mgr;-CO(3))[Cu(2)(H(2)O)(2)(EtMe(4)dien)(2)]} (ClO(4))(2).2H(2)O (3), EtMe(4)dien = N'-ethyl-N,N,N",N"-tetramethylbis(2-aminoethane)amine; and {(&mgr;-CO(3))[Cu(2)(H(2)O)(Me(5)dien)(2)]}(ClO(4))(2).H(2)O (4), Me(5)dien = N,N,N',N",N"-pentamethylbis(2-aminoethane)amine. The crystal structures have been solved for 2, monoclinic system, space group P2(1)/n, formula [C(25)H(62)Cl(2)Cu(2)N(6)O(13)] with a = 12.763(6) Å, b = 25.125(8) Å, c = 13.261(4) Å, beta = 111.85(3) degrees, Z = 4, and for 3, triclinic system, space group P&onemacr;, formula [C(21)H(58)Cl(2)Cu(2)N(6)O(15)] with a = 8.412(3) Å, b = 14.667(4) Å, c = 16.555(5) Å, alpha = 99.66(2) degrees, beta = 102.14(2) degrees, gamma = 104.72(2) degrees, Z = 2. Susceptibility measurements show ferromagnetic behavior (J = +6.7(6) cm(-)(1)) for the trinuclear compound 1 whereas 2-4 are antiferromagnetically coupled with J = -17.8(8), -125.5(9), and -21.2(3) cm(-)(1) respectively. Certain synthetic aspects that may be related to the nuclearity of the copper(II) &mgr;-CO(3)(2-) compounds and the superexchange pathway for the different coordination modes of the carbonato bridge are discussed.

  15. Colossal enhancement in thermoelectric effect in a laterally coupled double-quantum-dot chain by the Coulomb interactions

    International Nuclear Information System (INIS)

    Xiong, Lun; Yi, Lin

    2014-01-01

    Thermoelectric effects, including Seebeck coefficient (S), thermal conductance (κ), and figure of merit (ZT), in a laterally coupled double-quantum-dot (DQD) chain with two external nonmagnetic contacts are investigated theoretically by the nonequilibrium Green's function formalism. In this system, the DQD chain between two contacts forms a main channel for thermal electrons transporting, and each QD in the main chain couples laterally to a dangling one. The numerical calculations show that the Coulomb interactions not only lead to the splitting of the asymmetrical double-peak structure of the Seebeck coefficient, but also make the thermal spectrum show a strong violation of the Wiedemann–Franz law, leading to a colossal enhancement in ZT. These results indicate that the coupled DQD chain has potential applications in the thermoelectric devices with high thermal efficiency.

  16. Fully coupled fluid-structure interaction model of reed valves in a multi-cylinder reciprocating piston compressor

    Science.gov (United States)

    Xie, F.; Nieter, J.; Lifson, A.; Reba, R.; Sishtla, V.

    2017-08-01

    For years compressor researchers have tried to account for the fluid interaction effect of the working fluid on valve motion in displacement compressors. In recent years, the computing capacities and available CFD and FEA programs have allowed fully coupled interaction of fluids and moving structures to be modelled more comprehensively. This paper describes our experience and results from developing a model of a multi-cylinder reciprocating piston compressor with suction and discharge valve systems that are fully coupled with the pressure pulsation in the adjacent plenum. Valve dynamics are captured by the model that affects compressor performance. The results show that higher running speed causes more discharge valve delay on closing due to higher pressure pulsation in discharge plenum. The acoustic property of the discharge plenum as it relates to valve motion is studied by the developed cost-effective standalone model.

  17. Comprehensive Characterization of Minichromosome Maintenance Complex (MCM) Protein Interactions Using Affinity and Proximity Purifications Coupled to Mass Spectrometry.

    Science.gov (United States)

    Dubois, Marie-Line; Bastin, Charlotte; Lévesque, Dominique; Boisvert, François-Michel

    2016-09-02

    The extensive identification of protein-protein interactions under different conditions is an important challenge to understand the cellular functions of proteins. Here we use and compare different approaches including affinity purification and purification by proximity coupled to mass spectrometry to identify protein complexes. We explore the complete interactome of the minichromosome maintenance (MCM) complex by using both approaches for all of the different MCM proteins. Overall, our analysis identified unique and shared interaction partners and proteins enriched for distinct biological processes including DNA replication, DNA repair, and cell cycle regulation. Furthermore, we mapped the changes in protein interactions of the MCM complex in response to DNA damage, identifying a new role for this complex in DNA repair. In summary, we demonstrate the complementarity of these approaches for the characterization of protein interactions within the MCM complex.

  18. Analyzing the Anomalous Dipole Moment Type Couplings of Heavy Quarks with FCNC Interactions at the CLIC

    International Nuclear Information System (INIS)

    Senol, A.; Tasci, A. T.; Verep, C.

    2014-01-01

    We examine both anomalous magnetic and dipole moment type couplings of a heavy quark via its single production with subsequent dominant standard model decay modes at the compact linear collider (CLIC). The signal and background cross sections are analyzed for heavy quark masses 600 and 700 GeV. We make the analysis to delimitate these couplings as well as to find the attainable integrated luminosities for 3σ observation limit

  19. Analytic derivative couplings for spin-flip configuration interaction singles and spin-flip time-dependent density functional theory

    International Nuclear Information System (INIS)

    Zhang, Xing; Herbert, John M.

    2014-01-01

    We revisit the calculation of analytic derivative couplings for configuration interaction singles (CIS), and derive and implement these couplings for its spin-flip variant for the first time. Our algorithm is closely related to the CIS analytic energy gradient algorithm and should be straightforward to implement in any quantum chemistry code that has CIS analytic energy gradients. The additional cost of evaluating the derivative couplings is small in comparison to the cost of evaluating the gradients for the two electronic states in question. Incorporation of an exchange-correlation term provides an ad hoc extension of this formalism to time-dependent density functional theory within the Tamm-Dancoff approximation, without the need to invoke quadratic response theory or evaluate third derivatives of the exchange-correlation functional. Application to several different conical intersections in ethylene demonstrates that minimum-energy crossing points along conical seams can be located at substantially reduced cost when analytic derivative couplings are employed, as compared to use of a branching-plane updating algorithm that does not require these couplings. Application to H 3 near its D 3h geometry demonstrates that correct topology is obtained in the vicinity of a conical intersection involving a degenerate ground state

  20. Average and extreme multi-atom Van der Waals interactions: Strong coupling of multi-atom Van der Waals interactions with covalent bonding

    Directory of Open Access Journals (Sweden)

    Finkelstein Alexei V

    2007-07-01

    Full Text Available Abstract Background The prediction of ligand binding or protein structure requires very accurate force field potentials – even small errors in force field potentials can make a 'wrong' structure (from the billions possible more stable than the single, 'correct' one. However, despite huge efforts to optimize them, currently-used all-atom force fields are still not able, in a vast majority of cases, even to keep a protein molecule in its native conformation in the course of molecular dynamics simulations or to bring an approximate, homology-based model of protein structure closer to its native conformation. Results A strict analysis shows that a specific coupling of multi-atom Van der Waals interactions with covalent bonding can, in extreme cases, increase (or decrease the interaction energy by about 20–40% at certain angles between the direction of interaction and the covalent bond. It is also shown that on average multi-body effects decrease the total Van der Waals energy in proportion to the square root of the electronic component of dielectric permittivity corresponding to dipole-dipole interactions at small distances, where Van der Waals interactions take place. Conclusion The study shows that currently-ignored multi-atom Van der Waals interactions can, in certain instances, lead to significant energy effects, comparable to those caused by the replacement of atoms (for instance, C by N in conventional pairwise Van der Waals interactions.

  1. Coulomb drag: a probe of electron interactions in coupled quantum wells

    DEFF Research Database (Denmark)

    Jauho, Antti-Pekka

    1996-01-01

    As semiconductor devices shrink in size and in dimensionality, interactions between charge carriers become more and more important. There is a simple physical reason behind this behavior: fewer carriers lead to less effective screening, and hence stronger effective interactions. A point in case...... are one-dimensional systems (quantum wires): there electron-electron interactions may lead to a behavior, which is qualitatively different from the standard Fermi liquid picture (Luttinger liquids). Electron-electron interactions also play a central role in the fractional quantum Hall effect, which...... be the study of quantum wires: there the interactions may lead to even more dramatic effects...

  2. Using full configuration interaction quantum Monte Carlo in a seniority zero space to investigate the correlation energy equivalence of pair coupled cluster doubles and doubly occupied configuration interaction

    International Nuclear Information System (INIS)

    Shepherd, James J.; Henderson, Thomas M.; Scuseria, Gustavo E.

    2016-01-01

    Over the past few years, pair coupled cluster doubles (pCCD) has shown promise for the description of strong correlation. This promise is related to its apparent ability to match results from doubly occupied configuration interaction (DOCI), even though the latter method has exponential computational cost. Here, by modifying the full configuration interaction quantum Monte Carlo algorithm to sample only the seniority zero sector of Hilbert space, we show that the DOCI and pCCD energies are in agreement for a variety of 2D Hubbard models, including for systems well out of reach for conventional configuration interaction algorithms. Our calculations are aided by the sign problem being much reduced in the seniority zero space compared with the full space. We present evidence for this and then discuss the sign problem in terms of the wave function of the system which appears to have a simplified sign structure.

  3. Mode stability analysis in the beam—wave interaction process for a three-gap Hughes-type coupled cavity chain

    International Nuclear Information System (INIS)

    Luo Ji-Run; Zhu Min; Guo Wei; Cui Jian

    2013-01-01

    Based on space-charge wave theory, the formulae of the beam—wave coupling coefficient and the beam-loaded conductance are given for the beam—wave interaction in an N-gap Hughes-type coupled cavity chain. The ratio of the non-beam-loaded quality factor of the coupled cavity chain to the beam quality factor is used to determine the stability of the beam—wave interaction. As an example, the stabilities of the beam—wave interaction in a three-gap Hughes-type coupled cavity chain are discussed with the formulae and the CST code for the operations of the 2π, π, and π/2 modes, respectively. The results show that stable operation of the 2π, π, and π/2 modes may all be realized in an extended-interaction klystron with the three-gap Hughes-type coupled cavity chain

  4. Repulsively interacting fermions in a two-dimensional deformed trap with spin-orbit coupling

    DEFF Research Database (Denmark)

    Marchukov, O. V.; Fedorov, D. V.; Jensen, A. S.

    2015-01-01

    We investigate a two-dimensional system of fermions with two internal (spin) degrees of freedom. It is confined by a deformed harmonic trap and subject to a Zeeman field, Rashba or Dresselhaus one-body spin-orbit couplings and two-body short range repulsion. We obtain self-consistent mean-field $N...

  5. Eoet-Wash constraints on multiple Yukawa interactions and on a coupling to ''isospin''

    International Nuclear Information System (INIS)

    Stubbs, C.W.

    1989-01-01

    The final results of our lead-source runs are presented. Our data rule out at 2σ the possibility of accounting for all the composition-dependent results in terms of a coupling to ''isospin.'' By exploiting the fact that our hillside layout is fairly complex, we have also set limits on multiple-Yukawa scenarios. 15 refs., 3 figs

  6. Numerical simulation of coupled binary gas-solid interaction during carbon dioxide sequestration in a coal bed

    International Nuclear Information System (INIS)

    Feng Qiyan; Zhou Lai; Chen Zhongwei; Liu Jishan

    2008-01-01

    Complicated coupled binary gas-solid interaction arises during carbon dioxide sequestration in a coal seam, which combines effects of CO 2 -CH 4 counter adsorption, CO 2 -CH 4 counter diffusion, binary gas flow and coal bed deformation. Through solving a set of coupled field governing equations, a novel full coupled Finite Element (FE) model was established by COMSOL Multiphysics. The new FE model was applied to the quantification of coal porous pressure, coal permeability, gas composition fraction and coal displacement when CO 2 was injected in a CH 4 saturated coal bed. Numerical results demonstrate that CH 4 is swept by the injected CO 2 accompanied by coal volumetric deformation. Compared to the single CH 4 in situ, CH 4 -CO 2 counter-diffusion induced coal swelling can make more compensation for coal shrinkage due to effective stress. Competing influences between the effective stress and the CH 4 -CO 2 counter-diffusion induced volume change governs the evolution of porous pressure and permeability, which is controlled by the porous pressure correspondingly. This achievement extends our ability to understand the coupled multi-physics of the CO 2 geological sequestration and CO 2 enhanced coal bed methane recovery under field conditions. (authors)

  7. Dzyaloshinskii-Moriya interaction in the presence of Rashba and Dresselhaus spin-orbit coupling

    Science.gov (United States)

    Valizadeh, Mohammad M.; Satpathy, S.

    2018-03-01

    Chiral order in magnetic structures is currently an area of considerable interest and leads to skyrmion structures and domain walls with certain chirality. The chiral structure originates from the Dzyaloshinskii-Moriya interaction caused by broken inversion symmetry and the spin-orbit interaction. In addition to the Rashba or Dresselhaus interactions, there may also exist substantial spin polarization in magnetic thin films. Here, we study the exchange interaction between two localized magnetic moments in the spin-polarized electron gas with both Rashba and Dresselhaus spin-orbit interaction present. Analytical expressions are found in certain limits in addition to what is known in the literature. The stability of the Bloch and Néel domain walls in magnetic thin films is discussed in light of our results.

  8. Modeling multicomponent ionic transport in groundwater with IPhreeqc coupling: Electrostatic interactions and geochemical reactions in homogeneous and heterogeneous domains

    DEFF Research Database (Denmark)

    Muniruzzaman, Muhammad; Rolle, Massimo

    2016-01-01

    is coupled with the geochemical code PHREEQC-3 by utilizing the IPhreeqc module, thus enabling to perform the geochemical calculations included in the PHREEQC's reaction package. The multicomponent reactive transport code is benchmarked with different 1-D and 2-D transport problems. Successively...... the electrostatic interactions during transport of charged ions in physically and chemically heterogeneous porous media. The modeling approach is based on the local charge balance and on the description of compound-specific and spatially variable diffusive/dispersive fluxes. The multicomponent ionic transport code......, conservative and reactive transport examples are presented to demonstrate the capability of the proposed model to simulate transport of charged species in heterogeneous porous media with spatially variable physical and chemical properties. The results reveal that the Coulombic cross-coupling between dispersive...

  9. Dynamics of interacting qubits coupled to a common bath: Non-Markovian quantum-state-diffusion approach

    International Nuclear Information System (INIS)

    Zhao Xinyu; Jing Jun; Corn, Brittany; Yu Ting

    2011-01-01

    Non-Markovian dynamics is studied for two interacting qubits strongly coupled to a dissipative bosonic environment. We derive a non-Markovian quantum-state-diffusion (QSD) equation for the coupled two-qubit system without any approximations, and in particular, without the Markov approximation. As an application and illustration of our derived time-local QSD equation, we investigate the temporal behavior of quantum coherence dynamics. In particular, we find a strongly non-Markovian regime where entanglement generation is significantly modulated by the environmental memory. Additionally, we study residual entanglement in the steady state by analyzing the steady-state solution of the QSD equation. Finally, we discuss an approximate QSD equation.

  10. Modified holographic Ricci dark energy coupled to interacting dark matter and a non-interacting baryonic component

    Energy Technology Data Exchange (ETDEWEB)

    Chimento, Luis P.; Richarte, Martin G. [Universidad de Buenos Aires, IFIBA, CONICET, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Forte, Monica [Universidad de Buenos Aires, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina)

    2013-01-15

    We examine a Friedmann-Robertson-Walker universe filled with interacting dark matter, modified holographic Ricci dark energy (MHRDE), and a decoupled baryonic component. The estimations of the cosmic parameters with Hubble data lead to an age of the universe of 13.17 Gyr and show that the MHRDE is free from the cosmic-age problem at low redshift (0{<=}z{<=}2) in contrast to holographic Ricci dark energy (HRDE) case. We constrain the parameters with the Union2 data set and contrast with the Hubble data. We also study the behavior of dark energy at early times by taking into account the severe bounds found at recombination era and/or at big bang nucleosynthesis. The inclusion of a non-interacting baryonic matter forces that the amount of dark energy at z{sub t} {proportional_to} O(1) changes abruptly implying that {Omega} {sub x} (z {approx_equal}1100)=0.03, so the bounds reported by the forecast of Planck and CMBPol experiments are more favored for the MHRDE model than in the case of HRDE cutoff. For the former model, we also find that at high redshift the fraction of dark energy varies from 0.006 to 0.002, then the amount of {Omega} {sub x} at the big bang nucleosynthesis era does not disturb the observed helium abundance in the universe provided that the bound {Omega} {sub x} (z {approx_equal}10 {sup 10}) <0.21 is hold. (orig.)

  11. Seismic response analysis of soil-structure interactive system using a coupled three-dimensional FE-IE method

    International Nuclear Information System (INIS)

    Ryu, Jeong-Soo; Seo, Choon-Gyo; Kim, Jae-Min; Yun, Chung-Bang

    2010-01-01

    This paper proposes a slightly new three-dimensional radial-shaped dynamic infinite elements fully coupled to finite elements for an analysis of soil-structure interaction system in a horizontally layered medium. We then deal with a seismic analysis technique for a three-dimensional soil-structure interactive system, based on the coupled finite-infinite method in frequency domain. The dynamic infinite elements are simulated for the unbounded domain with wave functions propagating multi-generated wave components. The accuracy of the dynamic infinite element and effectiveness of the seismic analysis technique may be demonstrated through a typical compliance analysis of square surface footing, an L-shaped mat concrete footing on layered soil medium and two kinds of practical seismic analysis tests. The practical analyses are (1) a site response analysis of the well-known Hualien site excited by all travelling wave components (primary, shear, Rayleigh waves) and (2) a generation of a floor response spectrum of a nuclear power plant. The obtained dynamic results show good agreement compared with the measured response data and numerical values of other soil-structure interaction analysis package.

  12. Interventions and Interactions: Understanding Coupled Human-Water Dynamics for Improved Water Resources Management in the Himalayas

    Science.gov (United States)

    Crootof, A.

    2017-12-01

    Understanding coupled human-water dynamics offers valuable insights to address fundamental water resources challenges posed by environmental change. With hydropower reshaping human-water interactions in mountain river basins, there is a need for a socio-hydrology framework—which examines two-way feedback loops between human and water systems—to more effectively manage water resources. This paper explores the cross-scalar interactions and feedback loops between human and water systems in river basins affected by run-of-the-river hydropower and highlights the utility of a socio-hydrology perspectives to enhance water management in the face of environmental change. In the Himalayas, the rapid expansion of run-of-the-river hydropower—which diverts streamflow for energy generation—is reconfiguring the availability, location, and timing of water resources. This technological intervention in the river basin not only alters hydrologic dyanmics but also shapes social outcomes. Using hydropower development in the highlands of Uttarakhand, India as a case study, I first illustrate how run-of-the-river projects transform human-water dynamics by reshaping the social and physical landscape of a river basin. Second, I emphasize how examining cross-scalar feedbacks among structural dynamics, social outcomes, and values and norms in this coupled human-water system can inform water management. Third, I present hydrological and social literature, raised separately, to indicate collaborative research needs and knowledge gaps for coupled human-water systems affected by run-of-the-river hydropower. The results underscore the need to understand coupled human-water dynamics to improve water resources management in the face of environmental change.

  13. Diagnosing the Sensitivity of Local Land-Atmosphere Coupling via the Soil Moisture-Boundary Layer Interaction

    Science.gov (United States)

    Santanello, Joseph A., Jr.; Peters-Lidard, Christa D.; Kumar, Sujay V.

    2011-01-01

    The inherent coupled nature of earth s energy and water cycles places significant importance on the proper representation and diagnosis of land atmosphere (LA) interactions in hydrometeorological prediction models. However, the precise nature of the soil moisture precipitation relationship at the local scale is largely determined by a series of nonlinear processes and feedbacks that are difficult to quantify. To quantify the strength of the local LA coupling (LoCo), this process chain must be considered both in full and as individual components through their relationships and sensitivities. To address this, recent modeling and diagnostic studies have been extended to 1) quantify the processes governing LoCo utilizing the thermodynamic properties of mixing diagrams, and 2) diagnose the sensitivity of coupled systems, including clouds and moist processes, to perturbations in soil moisture. This work employs NASA s Land Information System (LIS) coupled to the Weather Research and Forecasting (WRF) mesoscale model and simulations performed over the U.S. Southern Great Plains. The behavior of different planetary boundary layers (PBL) and land surface scheme couplings in LIS WRF are examined in the context of the evolution of thermodynamic quantities that link the surface soil moisture condition to the PBL regime, clouds, and precipitation. Specifically, the tendency toward saturation in the PBL is quantified by the lifting condensation level (LCL) deficit and addressed as a function of time and space. The sensitivity of the LCL deficit to the soil moisture condition is indicative of the strength of LoCo, where both positive and negative feedbacks can be identified. Overall, this methodology can be applied to any model or observations and is a crucial step toward improved evaluation and quantification of LoCo within models, particularly given the advent of next-generation satellite measurements of PBL and land surface properties along with advances in data assimilation

  14. Spatial and thickness dependence of coupling interaction of surface states and influence on transport and optical properties of few-layer Bi2Se3

    Science.gov (United States)

    Li, Zhongjun; Chen, Shi; Sun, Jiuyu; Li, Xingxing; Qiu, Huaili; Yang, Jinlong

    2018-02-01

    Coupling interaction between the bottom and top surface electronic states and the influence on transport and optical properties of Bi2Se3 thin films with 1-8 quintuple layers (QLs) have been investigated by first principles calculations. Obvious spatial and thickness dependences of coupling interaction are found by analyzing hybridization of two surface states. In the thin film with a certain thickness, from the outer to inner atomic layers, the coupling interaction exhibits an increasing trend. On the other hand, as thickness increases, the coupling interaction shows a disproportionate decrease trend. Moreover, the system with 3 QLs exhibits stronger interaction than that with 2 QLs. The presence of coupling interaction would suppress destructive interference of surface states and enhance resistance in various degrees. In view of the inversely proportional relation to transport channel width, the resistance of thin films should show disproportionate thickness dependence. This prediction is qualitatively consistent with the transport measurements at low temperature. Furthermore, the optical properties also exhibit obvious thickness dependence. Especially as the thickness increases, the coupling interaction results in red and blue shifts of the multiple-peak structures in low and high energy regions of imaginary dielectric function, respectively. The red shift trend is in agreement with the recent experimental observation and the blue shift is firstly predicted by the present calculation. The present results give a concrete understanding of transport and optical properties in devices based on Bi2Se3 thin films with few QLs.

  15. Radionuclide behavior in water saturated porous media: Diffusion and infiltration coupling of thermodynamically and kinetically controlled radionuclide water - mineral interactions

    International Nuclear Information System (INIS)

    Spasennykh, M.Yu.; Apps, J.A.

    1995-05-01

    A model is developed describing one dimensional radionuclide transport in porous media coupled with locally reversible radionuclide water-mineral exchange reactions and radioactive decay. Problems are considered in which radionuclide transport by diffusion and infiltration processes occur in cases where radionuclide water-solid interaction are kinetically and thermodynamically controlled. The limits of Sr-90 and Cs-137 migration are calculated over a wide range of the problem variables (infiltration velocity, distribution coefficients, and rate constants of water-mineral radionuclide exchange reactions)

  16. Electron paramagnetic resonance g-tensors from state interaction spin-orbit coupling density matrix renormalization group

    Science.gov (United States)

    Sayfutyarova, Elvira R.; Chan, Garnet Kin-Lic

    2018-05-01

    We present a state interaction spin-orbit coupling method to calculate electron paramagnetic resonance g-tensors from density matrix renormalization group wavefunctions. We apply the technique to compute g-tensors for the TiF3 and CuCl42 - complexes, a [2Fe-2S] model of the active center of ferredoxins, and a Mn4CaO5 model of the S2 state of the oxygen evolving complex. These calculations raise the prospects of determining g-tensors in multireference calculations with a large number of open shells.

  17. Method of Measuring the Coupled Lattice Functions at the Interaction Point in e sup + e sup - Storage Rings

    CERN Document Server

    Cai, Y

    2003-01-01

    We have investigate a method of measuring the complete lattice functions including the coupling parameters at any azimuthal position in a periodic an symplectic system. In particular, the method is applied to measure the lattice functions at the interaction point where the beams collide. It has been demonstrate that a complete set of lattice functions can be accurately measured with two adjacent beam position monitors and the known transformation matrix between them. As a by-product, the method also automatically measures the complete one-turn matrix.

  18. Exchange electron-hole interaction of two-dimensional magnetoexcitons under the influence of the Rashba spin-orbit coupling

    International Nuclear Information System (INIS)

    Moskalenko, S.A.; Podlesny, I.V.; Lelyakov, I.A.; Novikov, B.V.; Kiselyova, E.S.; Gherciu, L.

    2011-01-01

    The Rashba spin-orbit coupling (RSOC) in the case of two-dimensional (2D) electrons and holes in a strong perpendicular magnetic field was studied. The spinor-type wave functions are characterized by different numbers of Landau levels in different spin projections. For electrons they differ by 1 as was established earlier by Rashba, whereas for holes they differ by 3. Two lowest electron states and four lowest hole states of Landau quantization give rise to eight 2D magnetoexciton states. The exchange electron-hole interaction in the frame of these states is investigated.

  19. Quantum ring with the Rashba spin-orbit interaction in the regime of strong light-matter coupling

    Science.gov (United States)

    Kozin, V. K.; Iorsh, I. V.; Kibis, O. V.; Shelykh, I. A.

    2018-04-01

    We developed the theory of electronic properties of semiconductor quantum rings with the Rashba spin-orbit interaction irradiated by an off-resonant high-frequency electromagnetic field (dressing field). Within the Floquet theory of periodically driven quantum systems, it is demonstrated that the dressing field drastically modifies all electronic characteristics of the rings, including spin-orbit coupling, effective electron mass, and optical response. In particular, the present effect paves the way to controlling the spin polarization of electrons with light in prospective ring-shaped spintronic devices.

  20. Interactivity And Mental Arithmetic: Coupling Mind And World Transforms And Enhances Performance

    Directory of Open Access Journals (Sweden)

    Guthrie Lisa G.

    2015-06-01

    Full Text Available Interactivity has been linked to better performance in problem solving, due in part to a more efficient allocation of attentional resources, a better distribution of cognitive load, but perhaps more important by enabling the reasoner to shape and reshape the physical problem presentation to promote the development of the problem solution. Interactivity in solving quotidian arithmetic problems involves gestures, pointing, and the recruitment of artefacts to facilitate computation and augment efficiency. In the experiment reported here, different types of interactivity were examined with a series of mental arithmetic problems. Using a repeated-measures design, participants solved series of five 11-digit sums in four conditions that varied in the type of interactivity: (i no interactivity (participants solved the problems with their hands on the table top, (ii pointing (participants could point at the numbers, (iii pen and paper (participants could note interim totals with a pen, and (iv tokens (the sums were presented as 11 numbered tokens the arrangement of which participants were free to modify as they proceeded to the solution. Performance in the four conditions was measured in terms of accuracy, calculation error, and efficiency (a ratio composed of the proportion correct over the proportion of time invested in working on the sums. These quantitative analyses were supplemented by a detailed qualitative examination of a participant’s actions in the different conditions. The integration of artefacts, such as tokens or a pen, offered reasoners the opportunity to reconfigure the physical presentation of the problem, enacting different arithmetic strategies: the affordance landscape shifts as the problem trajectory is enacted through interactivity, and this generally produced better “mental” arithmetic performance. Participants also felt more positive about and better engaged with the task when they could reconfigure the problem presentation

  1. Development of a coupled lattice Boltzmann and finite element method for fluid-structure interaction problems

    International Nuclear Information System (INIS)

    Jo, Jong Chull; Roh, Kyung Wan; Jhung, Myung Jo

    2006-12-01

    During this work period, a preliminary research has been conducted in the three different and related areas as stated in the proposal: literature survey, preliminary feasibility study of LBM and FEM coupling for FSI problems, and benchmark problems. As far as the literature review was concerned, approximately one hundred articles were found for the LBM techniques and critical review has been performed. The reviewed articles were classified into several topics that are useful for a subsequent development of the proposed computer program. Those topics included immiscible multicomponent flows, flow with energy transport, coupled multi-physics applications, application of the boundary conditions, irregular lattices, and turbulence. Furthermore, some fundamental review of the LBM was also included in this report. Secondly, a description of the LBM and FEM coupling program, which has been developed so far, was described here along with some demonstration examples. The preliminary study showed a great potential of the proposed technique for FSI application. A sample computer program list is also attached as Appendix A. As a future benchmark study, a set of test cases were proposed so that experimental data would be obtained in the next phase of the study. These data would be beneficial to understand the fundamental physics of the FSI nature under different basic conditions, and also provide benchmark results against which the developed program at a later stage could be validated. Finally, the future research direction as the extension of the present work is provided with emphasis on its goal, as well as merits and benefits resulting from the proposed research for the regulatory evaluation activities of KINS and the associated technical activities of industries such as design, manufacturing, fabrication, operation and maintenance

  2. Coupled Vulnerability and Resilience: the Dynamics of Cross-Scale Interactions in Post-Katrina New Orleans

    Directory of Open Access Journals (Sweden)

    Kevin F. Gotham

    2011-09-01

    Full Text Available We investigate the impact of trauma on cross-scale interactions in order to identify the major social-ecological factors affecting the pace and trajectory of post-Katrina rebuilding in New Orleans, Louisiana, USA. Disaster and traumatic events create and activate networks and linkages at different spatial and institutional levels to provide information and resources related to post-trauma recovery and rebuilding. The extension, intensification, and acceleration of cross-scale linkages and interactions in response to trauma alter organizational couplings, which then contribute to the vulnerability and resilience of social-ecological systems. Rather than viewing urban ecosystems as either resilient or vulnerable, we conceptualize them as embodying both resilient and vulnerable components. This integrated approach directs analytical attention to the impact of socio-legal regulations, government policies, and institutional actions on resilience and vulnerability, which are also systemic properties of urban ecosystems.

  3. Soil-structure Interaction in the Seismic Response of Coupled Wall-frame Structures on Pile Foundations

    International Nuclear Information System (INIS)

    Carbonari, S.; Dezi, F.; Leoni, G.

    2008-01-01

    This paper presents a study on the seismic response of coupled wall-frame structures founded on piles. A complete soil-structure interaction analysis is carried out with reference to a case study. Three different soils and seven real accelerograms are considered. Local site response analyses are performed in order to evaluate the incoming free-field motion at different depths and the ground motion amplifications. A numerical model, accounting for the pile-soil-pile interaction and for material and radiation damping, is used to evaluate the impedance matrix and the foundation input motion. The domain decomposition technique is adopted to perform time-domain seismic analyses introducing Lumped Parameter Models to take into account the impedance of the soil-structure system. Applications show that the rocking phenomena affect the behaviour of the structure by changing the base shear distribution within the wall and the frame and by increasing the structural displacements

  4. Dynamical Bayesian inference of time-evolving interactions: From a pair of coupled oscillators to networks of oscillators

    Science.gov (United States)

    Duggento, Andrea; Stankovski, Tomislav; McClintock, Peter V. E.; Stefanovska, Aneta

    2012-12-01

    Living systems have time-evolving interactions that, until recently, could not be identified accurately from recorded time series in the presence of noise. Stankovski [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.109.024101 109, 024101 (2012)] introduced a method based on dynamical Bayesian inference that facilitates the simultaneous detection of time-varying synchronization, directionality of influence, and coupling functions. It can distinguish unsynchronized dynamics from noise-induced phase slips. The method is based on phase dynamics, with Bayesian inference of the time-evolving parameters being achieved by shaping the prior densities to incorporate knowledge of previous samples. We now present the method in detail using numerically generated data, data from an analog electronic circuit, and cardiorespiratory data. We also generalize the method to encompass networks of interacting oscillators and thus demonstrate its applicability to small-scale networks.

  5. Similarity-transformed perturbation theory on top of truncated local coupled cluster solutions: Theory and applications to intermolecular interactions

    Energy Technology Data Exchange (ETDEWEB)

    Azar, Richard Julian, E-mail: julianazar2323@berkeley.edu; Head-Gordon, Martin, E-mail: mhg@cchem.berkeley.edu [Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2015-05-28

    Your correspondents develop and apply fully nonorthogonal, local-reference perturbation theories describing non-covalent interactions. Our formulations are based on a Löwdin partitioning of the similarity-transformed Hamiltonian into a zeroth-order intramonomer piece (taking local CCSD solutions as its zeroth-order eigenfunction) plus a first-order piece coupling the fragments. If considerations are limited to a single molecule, the proposed intermolecular similarity-transformed perturbation theory represents a frozen-orbital variant of the “(2)”-type theories shown to be competitive with CCSD(T) and of similar cost if all terms are retained. Different restrictions on the zeroth- and first-order amplitudes are explored in the context of large-computation tractability and elucidation of non-local effects in the space of singles and doubles. To accurately approximate CCSD intermolecular interaction energies, a quadratically growing number of variables must be included at zeroth-order.

  6. Emission Noise in an Interacting Quantum Dot: Role of Inelastic Scattering and Asymmetric Coupling to the Reservoirs

    Science.gov (United States)

    Crépieux, A.; Sahoo, S.; Duong, T. Q.; Zamoum, R.; Lavagna, M.

    2018-03-01

    A theory is developed for the emission noise at frequency ν in a quantum dot in the presence of Coulomb interactions and asymmetric couplings to the reservoirs. We give an analytical expression for the noise in terms of the various transmission amplitudes. Including the inelastic scattering contribution, it can be seen as the analog of the Meir-Wingreen formula for the current. A physical interpretation is given on the basis of the transmission of one electron-hole pair to the concerned reservoir where it emits an energy after recombination. We then treat the interactions by solving the self-consistent equations of motion for the Green functions. The results for the noise derivative versus e V show a zero value until e V =h ν , followed by a Kondo peak in the Kondo regime, in good agreement with recent measurements in carbon nanotube quantum dots.

  7. Implementing a Loosely Coupled Fluid Structure Interaction Finite Element Model in PHASTA

    Science.gov (United States)

    Pope, David

    Fluid Structure Interaction problems are an important multi-physics phenomenon in the design of aerospace vehicles and other engineering applications. A variety of computational fluid dynamics solvers capable of resolving the fluid dynamics exist. PHASTA is one such computational fluid dynamics solver. Enhancing the capability of PHASTA to resolve Fluid-Structure Interaction first requires implementing a structural dynamics solver. The implementation also requires a correction of the mesh used to solve the fluid equations to account for the deformation of the structure. This results in mesh motion and causes the need for an Arbitrary Lagrangian-Eulerian modification to the fluid dynamics equations currently implemented in PHASTA. With the implementation of both structural dynamics physics, mesh correction, and the Arbitrary Lagrangian-Eulerian modification of the fluid dynamics equations, PHASTA is made capable of solving Fluid-Structure Interaction problems.

  8. Coupled electrostatic and material surface stresses yield anomalous particle interactions and deformation

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, B. A., E-mail: bkemp@astate.edu; Nikolayev, I. [College of Engineering, Arkansas State University, Jonesboro, Arkansas 72467 (United States); Sheppard, C. J. [College of Sciences and Mathematics, Arkansas State University, Jonesboro, Arkansas 72467 (United States)

    2016-04-14

    Like-charges repel, and opposite charges attract. This fundamental tenet is a result of Coulomb's law. However, the electrostatic interactions between dielectric particles remain topical due to observations of like-charged particle attraction and the self-assembly of colloidal systems. Here, we show, using both an approximate description and an exact solution of Maxwell's equations, that nonlinear charged particle forces result even for linear material systems and can be responsible for anomalous electrostatic interactions such as like-charged particle attraction and oppositely charged particle repulsion. Furthermore, these electrostatic interactions and the deformation of such particles have fundamental implications for our understanding of macroscopic electrodynamics.

  9. Detection of light-matter interaction in the weak-coupling regime by quantum light

    Science.gov (United States)

    Bin, Qian; Lü, Xin-You; Zheng, Li-Li; Bin, Shang-Wu; Wu, Ying

    2018-04-01

    "Mollow spectroscopy" is a photon statistics spectroscopy, obtained by scanning the quantum light scattered from a source system. Here, we apply this technique to detect the weak light-matter interaction between the cavity and atom (or a mechanical oscillator) when the strong system dissipation is included. We find that the weak interaction can be measured with high accuracy when exciting the target cavity by quantum light scattered from the source halfway between the central peak and each side peak. This originally comes from the strong correlation of the injected quantum photons. In principle, our proposal can be applied into the normal cavity quantum electrodynamics system described by the Jaynes-Cummings model and an optomechanical system. Furthermore, it is state of the art for experiment even when the interaction strength is reduced to a very small value.

  10. Competing ferromagnetic and anti-ferromagnetic interactions in iron nitride ζ-Fe2N

    Science.gov (United States)

    Rao, K. Sandeep; Salunke, H. G.

    2018-03-01

    The paper discusses the magnetic state of zeta phase of iron nitride viz. ζ-Fe2N on the basis of spin polarized first principles electronic structure calculations together with a review of already published data. Results of our first principles study suggest that the ground state of ζ-Fe2N is ferromagnetic (FM) with a magnetic moment of 1.528μB on the Fe site. The FM ground state is lower than the anti-ferromagnetic (AFM) state by 8.44 meV and non-magnetic (NM) state by 191 meV per formula unit. These results are important in view of reports which claim that ζ-Fe2N undergoes an AFM transition below 10 K and others which do not observe any magnetic transition up to 4.2 K. We argue that the experimental results of AFM transition below 10 K are inconclusive and we propose the presence of competing FM and AFM superexchange interactions between Fe sites mediated by nitrogen atoms, which are consistent with Goodenough-Kanamori-Anderson rules. We find that the anti-ferromagnetically coupled Fe sites are outnumbered by ferromagnetically coupled Fe sites leading to a stable FM ground state. A Stoner analysis of the results also supports our claim of a FM ground state.

  11. Bolt-Grout Interactions in Elastoplastic Rock Mass Using Coupled FEM-FDM Techniques

    Directory of Open Access Journals (Sweden)

    Debasis Deb

    2010-01-01

    Full Text Available Numerical procedure based on finite element method (FEM and finite difference method (FDM for the analysis of bolt-grout interactions are introduced in this paper. The finite element procedure incorporates elasto-plastic concepts with Hoek and Brown yield criterion and has been applied for rock mass. Bolt-grout interactions are evaluated based on finite difference method and are embedded in the elasto-plastic procedures of FEM. The experimental validation of the proposed FEM-FDM procedures and numerical examples of a bolted tunnel are provided to demonstrate the efficacy of the proposed method for practical applications.

  12. Coupled interactions of organized deep convection over the tropical western pacific

    Energy Technology Data Exchange (ETDEWEB)

    Hong, X.; Raman, S. [North Carolina State Univ., Raleigh, NC (United States)

    1996-04-01

    The relationship between sea surface temperature (SST) and deep convection is complex. In general, deep convection occurs more frequently and with more intensity as SSTs become higher. This theory assumes that the atmospheric stability is sufficiently reduced to allow the onset of moist convection. However, the amount and intensity of convection observed tends to decrease with increasing SST because very warm SSTs. A reason for such decrease is the enhancements to surface fluxes of heat and moisture out of the ocean surface because of the vertical overturning associated with deep convection. Early studies used the radiative-convective models of the atmosphere to examine the role of the convective exchange of heat and moisture in maintaining the vertical temperature profile. In this paper we use a Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) to simulate a squall line over a tropical ocean global atmosphere/coupled ocean atmosphere response experiment (TOGA/COARE) area and to investigate how the ocean cooling mechanisms associated with organized deep convection act to limit tropical SSTs.

  13. Effect of cubic Dresselhaus interaction on the longitudinal optical conductivity of a spin-orbit coupled system

    Science.gov (United States)

    Cruz, Elmer; López-Bastidas, Catalina; Maytorena, Jesús A.

    2018-03-01

    We investigate the effect of the oft-neglected cubic terms of the Dresselhaus spin-orbit coupling on the longitudinal current response of a two-dimensional electron gas with both Rashba and linear Dresselhaus interactions. For a quantum well grown in the [001] direction, the changes caused by these nonlinear-in-momentum terms on the absorption spectrum become more notable under SU(2) symmetry conditions, when the Rashba and linear Dresselhaus coupling strengths are tuned to be equal. The longitudinal optical response no longer vanishes then and shows a strong dependence on the direction of the externally applied electric field, giving a signature of the relative size of several spin-orbit contributions. This anisotropic response arises from the nonisotropic splitting of the spin states induced by the interplay of Rashba and Dresselhaus couplings. However, the presence of cubic terms introduces characteristic spectral features and can modify the overall shape of the spectra for some values of the relative sizes of the spin-orbit parameters. We compare this behavior to the case of a sample with [110] crystal orientation which, under conditions of spin-preserving symmetry, has a collinear spin-orbit vector field that leads to vanishing conductivity, even in the presence of cubic terms. In addition to the control through the driven frequency or electrical gating, such a directional aspect of the current response suggests new ways of manipulation and supports the use of interband optics as a sensitive probe of spin-orbit mechanisms in semiconductor spintronics.

  14. Coupled thermal-fluid analysis with flowpath-cavity interaction in a gas turbine engine

    Science.gov (United States)

    Fitzpatrick, John Nathan

    This study seeks to improve the understanding of inlet conditions of a large rotor-stator cavity in a turbofan engine, often referred to as the drive cone cavity (DCC). The inlet flow is better understood through a higher fidelity computational fluid dynamics (CFD) modeling of the inlet to the cavity, and a coupled finite element (FE) thermal to CFD fluid analysis of the cavity in order to accurately predict engine component temperatures. Accurately predicting temperature distribution in the cavity is important because temperatures directly affect the material properties including Young's modulus, yield strength, fatigue strength, creep properties. All of these properties directly affect the life of critical engine components. In addition, temperatures cause thermal expansion which changes clearances and in turn affects engine efficiency. The DCC is fed from the last stage of the high pressure compressor. One of its primary functions is to purge the air over the rotor wall to prevent it from overheating. Aero-thermal conditions within the DCC cavity are particularly challenging to predict due to the complex air flow and high heat transfer in the rotating component. Thus, in order to accurately predict metal temperatures a two-way coupled CFD-FE analysis is needed. Historically, when the cavity airflow is modeled for engine design purposes, the inlet condition has been over-simplified for the CFD analysis which impacts the results, particularly in the region around the compressor disc rim. The inlet is typically simplified by circumferentially averaging the velocity field at the inlet to the cavity which removes the effect of pressure wakes from the upstream rotor blades. The way in which these non-axisymmetric flow characteristics affect metal temperatures is not well understood. In addition, a constant air temperature scaled from a previous analysis is used as the simplified cavity inlet air temperature. Therefore, the objectives of this study are: (a) model the

  15. On the coupling of statistic sum of canonical and large canonical ensemble of interacting particles

    International Nuclear Information System (INIS)

    Vall, A.N.

    2000-01-01

    Potentiality of refining the known result based on analytic properties of a great statistical sum, as a function of the absolute activity of the boundary integral contribution into statistical sum, is considered. A strict asymptotic ratio between statistical sums of canonical and large canonical ensemble of interacting particles was derived [ru

  16. Couples' experiences of interacting with outside others in chronic fatigue syndrome: a qualitative study.

    Science.gov (United States)

    Brooks, Joanna; King, Nigel; Wearden, Alison

    2014-03-01

    Social isolation and stigma are frequently reported by patients with chronic fatigue syndrome/myalgic encephalomyelitis and relationships in the home environment with those close to the patients (their 'significant others') may thus be particularly important. Rather little attention has yet been paid to the beliefs and experiences of 'significant others' themselves in this context. This study sought to explore in-depth the beliefs and experiences of both patients and 'significant others' in relation to chronic fatigue syndrome/myalgic encephalomyelitis. In-depth interviews using a semi-structured interview schedule designed around the core constructs of the Common-Sense Model of self-regulation were conducted with two patients with chronic fatigue syndrome/myalgic encephalomyelitis and their spouses. Interpretative Phenomenological Analysis was used to analyse interview data. Experiences of social interactions in relation to chronic fatigue syndrome/myalgic encephalomyelitis with others outside of the relationship dyad emerged as a key issue for all participants when reflecting on their experiences of living with the condition. These concerns are presented under two themes: interactions with healthcare professionals and interactions with the social world. It is evident that significant others play an important role in the lived experience of chronic fatigue syndrome/myalgic encephalomyelitis. For both patients and significant others, the wider social world and interactions with outside others may be important influences on dyadic coping in chronic fatigue syndrome/myalgic encephalomyelitis. Both future research and treatment interventions could usefully include a 'significant other' perspective.

  17. Neuroendocrine-immune interaction: regulation of inflammation via G-protein coupled receptors

    NARCIS (Netherlands)

    Verburg-van Kemenade, B.M.L.; Aa, van der L.M.; Chadzinska, M.K.

    2013-01-01

    Neuroendocrine- and immune systems interact in a bi-directional fashion to communicate the status of pathogen recognition to the brain and the immune response is influenced by physiological changes. The network of ligands and their receptors involved includes cytokines and chemokines,

  18. The influence of magnetostatic interactions in exchange-coupled composite particles

    Czech Academy of Sciences Publication Activity Database

    Vokoun, David; Beleggia, M.; De Graef, M.; Hou, H.C.; Lai, C.H.

    2010-01-01

    Roč. 43, č. 27 (2010), s. 275001-275007 ISSN 0022-3727 Institutional research plan: CEZ:AV0Z10100520 Keywords : magnetic recording materials * magnetic multilayers * magnetic thin film * magnetostac interaction * magnetic anisotropy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.105, year: 2010 http://iopscience.iop.org/0022-3727/43/27/275001/

  19. Nonstandard Work Schedules, Couple Desynchronization, and Parent-Child Interaction : A Mixed-Methods Analysis

    NARCIS (Netherlands)

    Taeht, Kadri; Mills, Melinda

    Many children live in households where either one or both parents work nonstandard schedules in the evening, night, or weekend. This study tests two competing hypotheses of whether nonstandard schedules result in lower levels of parent-child interaction or in more time with children. Using the first

  20. Spin Quantum Tunneling via Entangled States in a Dimer of Exchange-Coupled Single-Molecule Magnets

    Science.gov (United States)

    Tiron, R.; Wernsdorfer, W.; Foguet-Albiol, D.; Aliaga-Alcalde, N.; Christou, G.

    2003-11-01

    A new family of supramolecular, antiferromagnetically exchange-coupled dimers of single-molecule magnets (SMMs) has recently been reported. Each SMM acts as a bias on its neighbor, shifting the quantum tunneling resonances of the individual SMMs. Hysteresis loop measurements on a single crystal of SMM dimers have now established quantum tunneling of the magnetization via entangled states of the dimer. This shows that the dimer really does behave as a quantum mechanically coupled dimer, and also allows the measurement of the longitudinal and transverse superexchange coupling constants.

  1. Investigation of land ice-ocean interaction with a fully coupled ice-ocean model: 1. Model description and behavior

    Science.gov (United States)

    Goldberg, D. N.; Little, C. M.; Sergienko, O. V.; Gnanadesikan, A.; Hallberg, R.; Oppenheimer, M.

    2012-06-01

    Antarctic ice shelves interact closely with the ocean cavities beneath them, with ice shelf geometry influencing ocean cavity circulation, and heat from the ocean driving changes in the ice shelves, as well as the grounded ice streams that feed them. We present a new coupled model of an ice stream-ice shelf-ocean system that is used to study this interaction. The model is capable of representing a moving grounding line and dynamically responding ocean circulation within the ice shelf cavity. Idealized experiments designed to investigate the response of the coupled system to instantaneous increases in ocean temperature show ice-ocean system responses on multiple timescales. Melt rates and ice shelf basal slopes near the grounding line adjust in 1-2 years, and downstream advection of the resulting ice shelf thinning takes place on decadal timescales. Retreat of the grounding line and adjustment of grounded ice takes place on a much longer timescale, and the system takes several centuries to reach a new steady state. During this slow retreat, and in the absence of either an upward-or downward-sloping bed or long-term trends in ocean heat content, the ice shelf and melt rates maintain a characteristic pattern relative to the grounding line.

  2. Enhancement of exchange coupling interaction of NdFeB/MnBi hybrid magnets

    Science.gov (United States)

    Nguyen, Truong Xuan; Nguyen, Khanh Van; Nguyen, Vuong Van

    2018-03-01

    MnBi ribbons were fabricated by melt - spinning with subsequent annealing. The MnBi ribbons were ground and mixed with NdFeB commercial Magnequench powders (MQA). The hybrid powder mixtures were subjected thrice to the annealing and ball-milling route. The hybrid magnets (100 - x)NdFeB/xMnBi, x=0, 30, 40, 50 and 100 wt% were in-mold aligned in an 18 kOe magnetic field and warm compacted at 290 °C by 2000 psi uniaxial pressure for 10 min. An enhancement of the exchange coupling of NdFeB/MnBi hybrid magnets was obtained by optimizing the magnets' microstructures via annealing and ball-milling processes. The magnetic properties of prepared NdFeB/MnBi hybrid magnets were studied and discussed in details.

  3. Mena–GRASP65 interaction couples actin polymerization to Golgi ribbon linking

    Science.gov (United States)

    Tang, Danming; Zhang, Xiaoyan; Huang, Shijiao; Yuan, Hebao; Li, Jie; Wang, Yanzhuang

    2016-01-01

    In mammalian cells, the Golgi reassembly stacking protein 65 (GRASP65) has been implicated in both Golgi stacking and ribbon linking by forming trans-oligomers through the N-terminal GRASP domain. Because the GRASP domain is globular and relatively small, but the gaps between stacks are large and heterogeneous, it remains puzzling how GRASP65 physically links Golgi stacks into a ribbon. To explore the possibility that other proteins may help GRASP65 in ribbon linking, we used biochemical methods and identified the actin elongation factor Mena as a novel GRASP65-binding protein. Mena is recruited onto the Golgi membranes through interaction with GRASP65. Depleting Mena or disrupting actin polymerization resulted in Golgi fragmentation. In cells, Mena and actin were required for Golgi ribbon formation after nocodazole washout; in vitro, Mena and microfilaments enhanced GRASP65 oligomerization and Golgi membrane fusion. Thus Mena interacts with GRASP65 to promote local actin polymerization, which facilitates Golgi ribbon linking. PMID:26538023

  4. Contribution to the theoretical study of metallic systems containing rare earths: hyperfine interactions and exchange coupling

    International Nuclear Information System (INIS)

    Troper, A.

    1978-01-01

    A theoretical study involving rare earth impurities, which were embedded in transition metals (s-p or noble), from the point of view of the hyperfine interactions is presented. A model was created to describe a d-resonance (Anderson-Moriya) acting on a s-p conduction band which was strongly perturbed by a slater-koster potential, used to describe the rare earths which were diluted in matrices of transition elements. (author)

  5. Weak doping dependence of the antiferromagnetic coupling between nearest-neighbor Mn2 + spins in (Ba1 -xKx) (Zn1-yMny) 2As2

    Science.gov (United States)

    Surmach, M. A.; Chen, B. J.; Deng, Z.; Jin, C. Q.; Glasbrenner, J. K.; Mazin, I. I.; Ivanov, A.; Inosov, D. S.

    2018-03-01

    Dilute magnetic semiconductors (DMS) are nonmagnetic semiconductors doped with magnetic transition metals. The recently discovered DMS material (Ba1 -xKx) (Zn1-yMny) 2As2 offers a unique and versatile control of the Curie temperature TC by decoupling the spin (Mn2 +, S =5 /2 ) and charge (K+) doping in different crystallographic layers. In an attempt to describe from first-principles calculations the role of hole doping in stabilizing ferromagnetic order, it was recently suggested that the antiferromagnetic exchange coupling J between the nearest-neighbor Mn ions would experience a nearly twofold suppression upon doping 20% of holes by potassium substitution. At the same time, further-neighbor interactions become increasingly ferromagnetic upon doping, leading to a rapid increase of TC. Using inelastic neutron scattering, we have observed a localized magnetic excitation at about 13 meV associated with the destruction of the nearest-neighbor Mn-Mn singlet ground state. Hole doping results in a notable broadening of this peak, evidencing significant particle-hole damping, but with only a minor change in the peak position. We argue that this unexpected result can be explained by a combined effect of superexchange and double-exchange interactions.

  6. Randomly organized lipids and marginally stable proteins: a coupling of weak interactions to optimize membrane signaling.

    Science.gov (United States)

    Rice, Anne M; Mahling, Ryan; Fealey, Michael E; Rannikko, Anika; Dunleavy, Katie; Hendrickson, Troy; Lohese, K Jean; Kruggel, Spencer; Heiling, Hillary; Harren, Daniel; Sutton, R Bryan; Pastor, John; Hinderliter, Anne

    2014-09-01

    Eukaryotic lipids in a bilayer are dominated by weak cooperative interactions. These interactions impart highly dynamic and pliable properties to the membrane. C2 domain-containing proteins in the membrane also interact weakly and cooperatively giving rise to a high degree of conformational plasticity. We propose that this feature of weak energetics and plasticity shared by lipids and C2 domain-containing proteins enhance a cell's ability to transduce information across the membrane. We explored this hypothesis using information theory to assess the information storage capacity of model and mast cell membranes, as well as differential scanning calorimetry, carboxyfluorescein release assays, and tryptophan fluorescence to assess protein and membrane stability. The distribution of lipids in mast cell membranes encoded 5.6-5.8bits of information. More information resided in the acyl chains than the head groups and in the inner leaflet of the plasma membrane than the outer leaflet. When the lipid composition and information content of model membranes were varied, the associated C2 domains underwent large changes in stability and denaturation profile. The C2 domain-containing proteins are therefore acutely sensitive to the composition and information content of their associated lipids. Together, these findings suggest that the maximum flow of signaling information through the membrane and into the cell is optimized by the cooperation of near-random distributions of membrane lipids and proteins. This article is part of a Special Issue entitled: Interfacially Active Peptides and Proteins. Guest Editors: William C. Wimley and Kalina Hristova. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Presentation of two Lagrangian and coupled Eulerian-Lagrangian methods for fluid-structure interaction

    International Nuclear Information System (INIS)

    Blanchet, Y.; Obry, P.; Louvet, J.; Graveleau, J.

    1981-04-01

    Two different numerical methods have been implemented in two computer codes developed in CEA/DRNR, Cadarache, to predict the dynamic response of the containment of Super-Phenix reactor after a hypothetical energy excursion. Both codes are 2D-axisymmetric and solve the time-dependent flow of compressible fluids in the presence of deformable thin structures. The first one, called SIRIUS, uses only Lagrangian meshes; in the second one, called CASSIOPEE, the thick elastic-plastic materials are calculated in Lagrangian coordinates while fluids can be calculated either in Lagrangian or in Eulerian coordinates. The treatment of hydrodynamic, elastic-plastic thick domains then the thin shells models and the fluid-structure couplings are described in parallel for both codes. The efficiency and the limits of the previous methods are finally illustrated by comparison of measured and predicted strains of a vessel issued from one of the MARA experiments which are being purposely performed in Cadarache for validation of these codes in Super-Phenix scale models. These comparisons are encouraging and justify that the Super-Phenix reactor vessel response can be determined using the SIRIUS and CASSIOPEE codes

  8. Non double couple seismic sources, faults interaction and hypothesis of self-organized criticality

    Directory of Open Access Journals (Sweden)

    S. Yunga

    2005-01-01

    Full Text Available Non double couple (NDC sources are considered in framework of the hypothesis that the process of seismic rupture can be viewed as a result of complicated fault geometry and its segmentation. Analytical approach is found to reveal reliability of NDC measure taking into consideration the values of seismic moment tensor errors. The study focuses on the comparison of the deformation modes of the NDC sources with the stress states in its vicinity. The deformation modes of faulting and fracturing at a small scale in NDC earthquake focus and at regional scale in geological unit were investigated using at the last case summation of seismic moment tensors. These local and regional deformation modes in some of geodynamic regimes confirm the self-similarity assumption. For the whole data set scaling relations seem to be more complicated. This feature implies that besides stresses second order factors, as the hydrothermal or magmatic pore fluids in rock, influence source characteristics and bring new complications in scaling relations.

  9. Reliability techniques and Coupled BEM/FEM for interaction pile-soil

    Directory of Open Access Journals (Sweden)

    Ahmed SAHLI

    2017-06-01

    Full Text Available This paper deals with the development of a computational code for the modelling and verification of safety in relation to limit states of piles found in foundations of current structures. To this end, it makes use of reliability techniques for the probabilistic analysis of piles modelled with the finite element method (FEM coupled to the boundary element method (BEM. The soil is modelled with the BEM employing Mindlin's fundamental solutions, suitable for the consideration of a three-dimensional infinite half-space. The piles are modelled as bar elements with the MEF, each of which is represented in the BEM as a loading line. The finite element of the employed bar has four nodes and fourteen nodal parameters, three of which are displacements for each node plus two rotations for the top node. The slipping of the piles in relation to the mass is carried out using adhesion models to define the evolution of the shaft tensions during the transfer of load to the soil. The reliability analysis is based on three methods: first order second moment (FOSM, first order reliability method and Monte Carlo method.

  10. Jet-medium interactions at NLO in a weakly-coupled quark-gluon plasma

    International Nuclear Information System (INIS)

    Ghiglieri, Jacopo; Moore, Guy D.; Teaney, Derek

    2016-01-01

    We present an extension to next-to-leading order in the strong coupling constant g of the AMY effective kinetic approach to the energy loss of high momentum particles in the quark-gluon plasma. At leading order, the transport of jet-like particles is determined by elastic scattering with the thermal constituents, and by inelastic collinear splittings induced by the medium. We reorganize this description into collinear splittings, high-momentum-transfer scatterings, drag and diffusion, and particle conversions (momentum-preserving identity-changing processes). We show that this reorganized description remains valid to NLO in g, and compute the appropriate modifications of the drag, diffusion, particle conversion, and inelastic splitting coefficients. In addition, a new kinematic regime opens at NLO for wider-angle collinear bremsstrahlung. These semi-collinear emissions smoothly interpolate between the leading order high-momentum-transfer scatterings and collinear splittings. To organize the calculation, we introduce a set of Wilson line operators on the light-cone which determine the diffusion and identity changing coefficients, and we show how to evaluate these operators at NLO.

  11. Mode-coupling of interaction quenched ultracold bosons in periodically driven lattices

    Science.gov (United States)

    Mistakidis, Simeon; Schmelcher, Peter

    2016-05-01

    The out-of-equilibrium dynamics of interaction quenched finite ultracold bosonic ensembles in periodically driven one-dimensional optical lattices is investigated. As a first attempt a brief analysis of the dynamics caused exclusively by the periodically driven lattice is presented and the induced low-lying modes are introduced. It is shown that the periodic driving enforces the bosons in the outer wells to exhibit out-of-phase dipole-like modes, while in the central well the cloud experiences a local-breathing mode. The dynamical behavior of the system is investigated with respect to the driving frequency, revealing a resonant-like behavior of the intra-well dynamics. Subsequently, we drive the system to a highly non-equilibrium state by performing an interaction quench upon the periodically driven lattice. This protocol gives rise to admixtures of excitations in the outer wells, an enhanced breathing in the center and an amplification of the tunneling dynamics. As a result (of the quench) the system experiences multiple resonances between the inter- and intra-well dynamics at different quench amplitudes. Finally, our study reveals that the position of the resonances can be adjusted e.g. via the driving frequency or the atom number manifesting their many-body nature. Deutsche Forschungsgemeinschaft (DFG) in the framework of the SFB 925 ``Light induced dynamics and control of correlated quantum systems''.

  12. Intracellular calcium levels determine differential modulation of allosteric interactions within G protein-coupled receptor heteromers.

    Science.gov (United States)

    Navarro, Gemma; Aguinaga, David; Moreno, Estefania; Hradsky, Johannes; Reddy, Pasham P; Cortés, Antoni; Mallol, Josefa; Casadó, Vicent; Mikhaylova, Marina; Kreutz, Michael R; Lluís, Carme; Canela, Enric I; McCormick, Peter J; Ferré, Sergi

    2014-11-20

    The pharmacological significance of the adenosine A2A receptor (A2AR)-dopamine D2 receptor (D2R) heteromer is well established and it is being considered as an important target for the treatment of Parkinson’s disease and other neuropsychiatric disorders. However, the physiological factors that control its distinctive biochemical properties are still unknown. We demonstrate that different intracellular Ca2+ levels exert a differential modulation of A2AR-D2R heteromer-mediated adenylyl-cyclase and MAPK signaling in striatal cells. This depends on the ability of low and high Ca2+ levels to promote a selective interaction of the heteromer with the neuronal Ca2+-binding proteins NCS-1 and calneuron-1, respectively. These Ca2+-binding proteins differentially modulate allosteric interactions within the A2AR-D2R heteromer, which constitutes a unique cellular device that integrates extracellular (adenosine and dopamine) and intracellular (Ca+2) signals to produce a specific functional response.

  13. Mena-GRASP65 interaction couples actin polymerization to Golgi ribbon linking.

    Science.gov (United States)

    Tang, Danming; Zhang, Xiaoyan; Huang, Shijiao; Yuan, Hebao; Li, Jie; Wang, Yanzhuang

    2016-01-01

    In mammalian cells, the Golgi reassembly stacking protein 65 (GRASP65) has been implicated in both Golgi stacking and ribbon linking by forming trans-oligomers through the N-terminal GRASP domain. Because the GRASP domain is globular and relatively small, but the gaps between stacks are large and heterogeneous, it remains puzzling how GRASP65 physically links Golgi stacks into a ribbon. To explore the possibility that other proteins may help GRASP65 in ribbon linking, we used biochemical methods and identified the actin elongation factor Mena as a novel GRASP65-binding protein. Mena is recruited onto the Golgi membranes through interaction with GRASP65. Depleting Mena or disrupting actin polymerization resulted in Golgi fragmentation. In cells, Mena and actin were required for Golgi ribbon formation after nocodazole washout; in vitro, Mena and microfilaments enhanced GRASP65 oligomerization and Golgi membrane fusion. Thus Mena interacts with GRASP65 to promote local actin polymerization, which facilitates Golgi ribbon linking. © 2016 Tang et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  14. A cut-cell finite volume - finite element coupling approach for fluid-structure interaction in compressible flow

    Science.gov (United States)

    Pasquariello, Vito; Hammerl, Georg; Örley, Felix; Hickel, Stefan; Danowski, Caroline; Popp, Alexander; Wall, Wolfgang A.; Adams, Nikolaus A.

    2016-02-01

    We present a loosely coupled approach for the solution of fluid-structure interaction problems between a compressible flow and a deformable structure. The method is based on staggered Dirichlet-Neumann partitioning. The interface motion in the Eulerian frame is accounted for by a conservative cut-cell Immersed Boundary method. The present approach enables sub-cell resolution by considering individual cut-elements within a single fluid cell, which guarantees an accurate representation of the time-varying solid interface. The cut-cell procedure inevitably leads to non-matching interfaces, demanding for a special treatment. A Mortar method is chosen in order to obtain a conservative and consistent load transfer. We validate our method by investigating two-dimensional test cases comprising a shock-loaded rigid cylinder and a deformable panel. Moreover, the aeroelastic instability of a thin plate structure is studied with a focus on the prediction of flutter onset. Finally, we propose a three-dimensional fluid-structure interaction test case of a flexible inflated thin shell interacting with a shock wave involving large and complex structural deformations.

  15. A cut-cell finite volume – finite element coupling approach for fluid–structure interaction in compressible flow

    International Nuclear Information System (INIS)

    Pasquariello, Vito; Hammerl, Georg; Örley, Felix; Hickel, Stefan; Danowski, Caroline; Popp, Alexander; Wall, Wolfgang A.; Adams, Nikolaus A.

    2016-01-01

    We present a loosely coupled approach for the solution of fluid–structure interaction problems between a compressible flow and a deformable structure. The method is based on staggered Dirichlet–Neumann partitioning. The interface motion in the Eulerian frame is accounted for by a conservative cut-cell Immersed Boundary method. The present approach enables sub-cell resolution by considering individual cut-elements within a single fluid cell, which guarantees an accurate representation of the time-varying solid interface. The cut-cell procedure inevitably leads to non-matching interfaces, demanding for a special treatment. A Mortar method is chosen in order to obtain a conservative and consistent load transfer. We validate our method by investigating two-dimensional test cases comprising a shock-loaded rigid cylinder and a deformable panel. Moreover, the aeroelastic instability of a thin plate structure is studied with a focus on the prediction of flutter onset. Finally, we propose a three-dimensional fluid–structure interaction test case of a flexible inflated thin shell interacting with a shock wave involving large and complex structural deformations.

  16. Fluid and structure coupling analysis of the interaction between aqueous humor and iris.

    Science.gov (United States)

    Wang, Wenjia; Qian, Xiuqing; Song, Hongfang; Zhang, Mindi; Liu, Zhicheng

    2016-12-28

    Glaucoma is the primary cause of irreversible blindness worldwide associated with high intraocular pressure (IOP). Elevated intraocular pressure will affect the normal aqueous humor outflow, resulting in deformation of iris. However, the deformation ability of iris is closely related to its material properties. Meanwhile, the passive deformation of the iris aggravates the pupillary block and angle closure. The nature of the interaction mechanism of iris deformation and aqueous humor fluid flow has not been fully understood and has been somewhat a controversial issue. The purpose here was to study the effect of IOP, localization, and temperature on the flow of the aqueous humor and the deformation of iris interacted by aqueous humor fluid flow. Based on mechanisms of aqueous physiology and fluid dynamics, 3D model of anterior chamber (AC) was constructed with the human anatomical parameters as a reference. A 3D idealized standard geometry of anterior segment of human eye was performed. Enlarge the size of the idealization geometry model 5 times to create a simulation device by using 3D printing technology. In this paper, particle image velocimetry technology is applied to measure the characteristic of fluid outflow in different inlet velocity based on the device. Numerically calculations were made by using ANSYS 14.0 Finite Element Analysis. Compare of the velocity distributions to confirm the validity of the model. The fluid structure interaction (FSI) analysis was carried out in the valid geometry model to study the aqueous flow and iris change. In this paper, the validity of the model is verified through computation and comparison. The results indicated that changes of gravity direction of model significantly affected the fluid dynamics parameters and the temperature distribution in anterior chamber. Increased pressure and the vertical position increase the velocity of the aqueous humor fluid flow, with the value increased of 0.015 and 0.035 mm/s. The results

  17. Interaction between nucleotide binding sites on chloroplast coupling factor 1 during ATP hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Leckband, D.; Hammes, G.G.

    1987-04-21

    The initial hydrolysis of radioactively-labelled CaATP by chloroplast coupling factor 1 was studied with the quenched-flow method. The time course of hydrolysis can be described as a first-order conversion of the enzyme to an active form followed by steady-state formation of product. The rate constant for the first-order process is independent of substrate concentration but increased hyperbolically to a limiting value of 0.43 s/sup -1/ with increasing concentrations of free Ca/sup 2 +/. A mechanism involving a Ca/sup 2 +/-triggered conversion to an active form of the enzyme is consistent with the data. The steady-state rate varied sigmoidally with the CaATP concentration. Initial exchange of tightly bound ADP is complex: approx. 50% of the bound nucleotide is lost within 30 s, with complete exchange requiring several minutes. The first-order rate constant characterizing the rapid phase of the reaction increases hyperbolically to a limiting value of 0.26 s/sup -1/ as the concentration of CaATP is increased, indicating that the binding of CaATP to the enzyme promotes the exchange process. Modification of the quenched-flow apparatus permitted measurement of the rate of nucleotide exchange during steady-state catalysis. The value of the first-order rate constant characterizing this process is similar to the catalytic rate constant determined under identical conditions. When MgATP is tightly bound to the enzyme, none of the kinetic properties of the enzyme described above were significantly changes. The results obtained suggest a mechanism in which two sites on the enzyme participate in catalysis. Several possible mechanisms consistent with the data are discussed.

  18. Strongly coupled interaction between a ridge of fluid and an inviscid airflow

    KAUST Repository

    Paterson, C.

    2015-07-01

    © 2015 AIP Publishing LLC. The behaviour of a steady thin sessile or pendent ridge of fluid on an inclined planar substrate which is strongly coupled to the external pressure gradient arising from an inviscid airflow parallel to the substrate far from the ridge is described. When the substrate is nearly horizontal, a very wide ridge can be supported against gravity by capillary and/or external pressure forces; otherwise, only a narrower (but still wide) ridge can be supported. Classical thin-aerofoil theory is adapted to obtain the governing singular integro-differential equation for the profile of the ridge in each case. Attention is focused mainly on the case of a very wide sessile ridge. The effect of strengthening the airflow is to push a pinned ridge down near to its edges and to pull it up near to its middle. At a critical airflow strength, the upslope contact angle reaches the receding contact angle at which the upslope contact line de-pins, and continuing to increase the airflow strength beyond this critical value results in the de-pinned ridge becoming narrower, thicker, and closer to being symmetric in the limit of a strong airflow. The effect of tilting the substrate is to skew a pinned ridge in the downslope direction. Depending on the values of the advancing and receding contact angles, the ridge may first de-pin at either the upslope or the downslope contact line but, in general, eventually both contact lines de-pin. The special cases in which only one of the contact lines de-pins are also considered. It is also shown that the behaviour of a very wide pendent ridge is qualitatively similar to that of a very wide sessile ridge, while the important qualitative difference between the behaviour of a very wide ridge and a narrower ridge is that, in general, for the latter one or both of the contact lines may never de-pin.

  19. Coupled interactions between volatile activity and Fe oxidation state during arc crustal processes

    Science.gov (United States)

    Humphreys, Madeleine C.S.; Brooker, R; Fraser, D.C.; Burgisser, A; Mangan, Margaret T.; McCammon, C

    2015-01-01

    Arc magmas erupted at the Earth’s surface are commonly more oxidized than those produced at mid-ocean ridges. Possible explanations for this high oxidation state are that the transfer of fluids during the subduction process results in direct oxidation of the sub-arc mantle wedge, or that oxidation is caused by the effect of later crustal processes, including protracted fractionation and degassing of volatile-rich magmas. This study sets out to investigate the effect of disequilibrium crustal processes that may involve coupled changes in H2O content and Fe oxidation state, by examining the degassing and hydration of sulphur-free rhyolites. We show that experimentally hydrated melts record strong increases in Fe3+/∑Fe with increasing H2O concentration as a result of changes in water activity. This is relevant for the passage of H2O-undersaturated melts from the deep crust towards shallow crustal storage regions, and raises the possibility that vertical variations in fO2 might develop within arc crust. Conversely, degassing experiments produce an increase in Fe3+/∑Fe with decreasing H2O concentration. In this case the oxidation is explained by loss of H2 as well as H2O into bubbles during decompression, consistent with thermodynamic modelling, and is relevant for magmas undergoing shallow degassing en route to the surface. We discuss these results in the context of the possible controls on fO2 during the generation, storage and ascent of magmas in arc settings, in particular considering the timescales of equilibration relative to observation as this affects the quality of the petrological record of magmatic fO2.

  20. Isotropic background for interacting two fluid scenario coupled with zero mass scalar field in modified gravity

    International Nuclear Information System (INIS)

    Chirde, V.R.; Shekh, S.H.

    2016-01-01

    The modified theories of gravity have engrossed much attention in the last decade, especially f(R) gravity. In this contextual exploration, we investigate interaction between barotropic fluid and dark energy with zero-mass scalar field for the spatially homogeneous and isotropic flat FRW universe. In this universe, the field equations correspond to the particular choice of f(R) = R+bR m . The exact solutions of the field equations are obtained by applying volumetric power law and exponential law of expansion. In power and exponential law of expansion, the universe shows both matter dominated and DE era for b ≤ 0 and b ≥ 0 and remain present in dark era respectively, but power law model is fully occupying with real matter for b > 0 and for b < 0 exponential model expands with negative pressure and remain present in matter dominated phase respectively. The physical behavior of the universe has been discussed by using some physical quantities

  1. Ab initio/interpolated quantum dynamics on coupled electronic states with full configuration interaction wave functions

    International Nuclear Information System (INIS)

    Thompson, K.; Martinez, T.J.

    1999-01-01

    We present a new approach to first-principles molecular dynamics that combines a general and flexible interpolation method with ab initio evaluation of the potential energy surface. This hybrid approach extends significantly the domain of applicability of ab initio molecular dynamics. Use of interpolation significantly reduces the computational effort associated with the dynamics over most of the time scale of interest, while regions where potential energy surfaces are difficult to interpolate, for example near conical intersections, are treated by direct solution of the electronic Schroedinger equation during the dynamics. We demonstrate the concept through application to the nonadiabatic dynamics of collisional electronic quenching of Li(2p). Full configuration interaction is used to describe the wave functions of the ground and excited electronic states. The hybrid approach agrees well with full ab initio multiple spawning dynamics, while being more than an order of magnitude faster. copyright 1999 American Institute of Physics

  2. The coherence lifetime-borrowing effect in vibronically coupled molecular aggregates under non-perturbative system-environment interactions.

    Science.gov (United States)

    Yeh, Shu-Hao; Engel, Gregory S.; Kais, Sabre

    Recently it has been suggested that the long-lived coherences in some photosynthetic pigment-protein systems, such as the Fenna-Matthews-Olson complex, could be attributed to the mixing of the pigments' electronic and vibrational degrees of freedom. In order to verify whether this is the case and to understand its underlying mechanism, a theoretical model capable of including both the electronic excitations and intramolecular vibrational modes of the pigments is necessary. Our model simultaneously considers the electronic and vibrational degrees of freedom, treating the system-environment interactions non-perturbatively by implementing the hierarchical equations of motion approach. Here we report the simulated two-dimensional electronic spectra of vibronically coupled molecular dimers to demonstrate how the electronic coherence lifetimes can be extended by borrowing the lifetime from the vibrational coherences. Funded by Qatar National Research Fund and Qatar Environment and Energy Research Institute.

  3. Fast quantification of endogenous carbohydrates in plasma using hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Zhu, Bangjie; Liu, Feng; Li, Xituo; Wang, Yan; Gu, Xue; Dai, Jieyu; Wang, Guiming; Cheng, Yu; Yan, Chao

    2015-01-01

    Endogenous carbohydrates in biosamples are frequently highlighted as the most differential metabolites in many metabolomics studies. A simple, fast, simultaneous quantitative method for 16 endogenous carbohydrates in plasma has been developed using hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry. In order to quantify 16 endogenous carbohydrates in plasma, various conditions, including columns, chromatographic conditions, mass spectrometry conditions, and plasma preparation methods, were investigated. Different conditions in this quantified analysis were performed and optimized. The reproducibility, precision, recovery, matrix effect, and stability of the method were verified. The results indicated that a methanol/acetonitrile (50:50, v/v) mixture could effectively and reproducibly precipitate rat plasma proteins. Cold organic solvents coupled with vortex for 1 min and incubated at -20°C for 20 min were the most optimal conditions for protein precipitation and extraction. The results, according to the linearity, recovery, precision, matrix effect, and stability, showed that the method was satisfactory in the quantification of endogenous carbohydrates in rat plasma. The quantified analysis of endogenous carbohydrates in rat plasma performed excellently in terms of sensitivity, high throughput, and simple sample preparation, which met the requirement of quantification in specific expanded metabolomic studies after the global metabolic profiling research. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Desert dust and anthropogenic aerosol interactions in the Community Climate System Model coupled-carbon-climate model

    Directory of Open Access Journals (Sweden)

    N. Mahowald

    2011-02-01

    Full Text Available Coupled-carbon-climate simulations are an essential tool for predicting the impact of human activity onto the climate and biogeochemistry. Here we incorporate prognostic desert dust and anthropogenic aerosols into the CCSM3.1 coupled carbon-climate model and explore the resulting interactions with climate and biogeochemical dynamics through a series of transient anthropogenic simulations (20th and 21st centuries and sensitivity studies. The inclusion of prognostic aerosols into this model has a small net global cooling effect on climate but does not significantly impact the globally averaged carbon cycle; we argue that this is likely to be because the CCSM3.1 model has a small climate feedback onto the carbon cycle. We propose a mechanism for including desert dust and anthropogenic aerosols into a simple carbon-climate feedback analysis to explain the results of our and previous studies. Inclusion of aerosols has statistically significant impacts on regional climate and biogeochemistry, in particular through the effects on the ocean nitrogen cycle and primary productivity of altered iron inputs from desert dust deposition.

  5. Simultaneous analysis of multiple neurotransmitters by hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Tufi, Sara; Lamoree, Marja; de Boer, Jacob; Leonards, Pim

    2015-05-22

    Neurotransmitters are endogenous metabolites that allow the signal transmission across neuronal synapses. Their biological role is crucial for many physiological functions and their levels can be changed by several diseases. Because of their high polarity, hydrophilic interaction liquid chromatography (HILIC) is a promising tool for neurotransmitter analysis. Due to the large number of HILIC stationary phases available, an evaluation of the column performances and retention behaviors has been performed on five different commercial HILIC packing materials (silica, amino, amide and two zwitterionic stationary phases). Several parameters like the linear correlation between retention and the distribution coefficient (logD), the separation factor k and the column resolution Rs have been investigated and the column performances have been visualized with a heat map and hierarchical clustering analysis. An optimized and validated HILIC-MS/MS method based on the ZIC-cHILIC column is proposed for the simultaneous detection and quantification of twenty compounds consisting of neurotransmitters, precursors and metabolites: 3-methoxytyramine (3-MT), 5-hydroxyindoleacetic acid (5-HIAA), 5-hydroxy-L-tripthophan, acetylcholine, choline, L-3,4-dihydroxyphenylalanine (L-DOPA), dopamine, epinephrine, γ-aminobutyric acid (GABA), glutamate, glutamine, histamine, histidine, L-tryptophan, L-tyrosine, norepinephrine, normetanephrine, phenylalanine, serotonin and tyramine. The method was applied to neuronal metabolite profiling of the central nervous system of the freshwater snail Lymnaea stagnalis. This method is suitable to explore neuronal metabolism and its alteration in different biological matrices. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. A homogenization method for the analysis of a coupled fluid-structure interaction problem with inner solid structure

    International Nuclear Information System (INIS)

    Sigrist, Jean-Francois; Laine, Christian; Broc, Daniel

    2006-01-01

    The present paper exposes a homogenization method developed in order to perform the seismic analysis of a nuclear reactor with internal structures modelling and taking fluid structure interaction effects into account. The numerical resolution of fluid-structure interactions has made tremendous progress over the past decades and some applications of the various developed techniques in the industrial field can be found in the literature. As builder of nuclear naval propulsion reactors (ground prototype reactor or embarked reactor on submarines), DCN Propulsion has been working with French nuclear committee CEA for several years in order to integrate fluid-structure analysis in the design stage of current projects. In previous papers modal and seismic analyses of a nuclear reactor with fluid-structure interaction effect were exposed. The studies highlighted the importance of fluid- structure coupling phenomena in the industrial case and focussed on added mass and added stiffness effects. The numerical model used in the previous studies did not take into account the presence of internal structures within the pressure vessel. The present study aims at improving the numerical model of the nuclear reactor to take into account the presence of the internal structures. As the internal structures are periodical within the inner and outer structure of the pressure vessel the proposed model is based on the development of a homogenization method: the presence of internal structure and its effect on the fluid-structure physical interaction is taken into account, although they are not geometrically modeled. The basic theory of the proposed homogenization method is recalled, leading to the modification of fluid-structure coupling operator in the finite element model. The physical consistency of the method is proved by an evaluation of the system mass with the various mass operators (structure, fluid and fluid-structure operators). The method is exposed and validated in a 2 D case

  7. Patterns in coupled water and energy cycle: Modeling, synthesis with observations, and assessing the subsurface-landsurface interactions

    Science.gov (United States)

    Rahman, A.; Kollet, S. J.; Sulis, M.

    2013-12-01

    In the terrestrial hydrological cycle, the atmosphere and the free groundwater table act as the upper and lower boundary condition, respectively, in the non-linear two-way exchange of mass and energy across the land surface. Identifying and quantifying the interactions among various atmospheric-subsurface-landsurface processes is complicated due to the diverse spatiotemporal scales associated with these processes. In this study, the coupled subsurface-landsurface model ParFlow.CLM was applied over a ~28,000 km2 model domain encompassing the Rur catchment, Germany, to simulate the fluxes of the coupled water and energy cycle. The model was forced by hourly atmospheric data from the COSMO-DE model (numerical weather prediction system of the German Weather Service) over one year. Following a spinup period, the model results were synthesized with observed river discharge, soil moisture, groundwater table depth, temperature, and landsurface energy flux data at different sites in the Rur catchment. It was shown that the model is able to reproduce reasonably the dynamics and also absolute values in observed fluxes and state variables without calibration. The spatiotemporal patterns in simulated water and energy fluxes as well as the interactions were studied using statistical, geostatistical and wavelet transform methods. While spatial patterns in the mass and energy fluxes can be predicted from atmospheric forcing and power law scaling in the transition and winter months, it appears that, in the summer months, the spatial patterns are determined by the spatially correlated variability in groundwater table depth. Continuous wavelet transform techniques were applied to study the variability of the catchment average mass and energy fluxes at varying time scales. From this analysis, the time scales associated with significant interactions among different mass and energy balance components were identified. The memory of precipitation variability in subsurface hydrodynamics

  8. Low-temperature, non-stoichiometric oxygen isotope exchange coupled to Fe(II)-goethite interactions

    Energy Technology Data Exchange (ETDEWEB)

    Frierdich, Andrew J. [Univ. of Wisconsin, Madison, WI (United States); Univ. of Iowa, Iowa City, IA (United States); Beard, Brian L. [Univ. of Wisconsin, Madison, WI (United States); Rosso, Kevin M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Scherer, Michelle M. [Univ. of Iowa, Iowa City, IA (United States); Spicuzza, Michael J. [Univ. of Wisconsin, Madison, WI (United States); Valley, John W. [Univ. of Wisconsin, Madison, WI (United States); Johnson, Clark M. [Univ. of Wisconsin, Madison, WI (United States)

    2015-07-01

    The oxygen isotope composition of natural iron oxide minerals has been widely used as a paleoclimate proxy. Interpretation of their stable isotope compositions, however, requires accurate knowledge of isotopic fractionation factors and an understanding of their isotopic exchange kinetics, the latter of which informs us how diagenetic processes may alter their isotopic compositions. Prior work has demonstrated that crystalline iron oxides do not significantly exchange oxygen isotopes with pure water at low temperature, which has restricted studies of isotopic fractionation factors to precipitation experiments or theoretical calculations. Using a double three-isotope method (¹⁸O-¹⁷O-¹⁶O and ⁵⁷Fe-⁵⁶Fe-⁵⁴Fe) we compare O and Fe isotope exchange kinetics, and demonstrate, for the first time, that O isotope exchange between structural O in crystalline goethite and water occurs in the presence of aqueous Fe(II) (Fe(II)aq) at ambient temperature (i.e., 22–50 °C). The three-isotope method was used to extrapolate partial exchange results to infer the equilibrium, mass-dependent isotope fractionations between goethite and water. In addition, this was combined with a reversal approach to equilibrium by reacting goethite in two unique waters that vary in composition by about 16‰ in ¹⁸O/¹⁶O ratios. Our results show that interactions between Fe(II)aq and goethite catalyzes O isotope exchange between the mineral and bulk fluid; no exchange (within error) is observed when goethite is suspended in ¹⁷O-enriched water in the absence of Fe(II)aq. In contrast, Fe(II)-catalyzed O isotope exchange is accompanied by significant changes in ¹⁸O/¹⁶O ratios. Despite significant O exchange, however, we observed disproportionate amounts of Fe versus O exchange, where Fe isotope exchange in goethite was roughly three times that of O. This disparity provides novel insight into the reactivity of oxide minerals in aqueous

  9. Information entropy properties of the atoms in the system of coupled Λ-type three-level atoms interacting with coherent field in Kerr medium

    International Nuclear Information System (INIS)

    Li Ke; Ling Weijun

    2011-01-01

    The information entropy properties of the atoms of coupled Λ-type three-level atoms interacting with coherent field are studied by means of quantum theory, and discussed the time evolutions of the information entropy of the atoms via the average photon number, initial state of the atoms, detuning, coupling constant between the atoms and the coefficient of Kerr medium. Numerical calculation results show that the time evolutions of the information entropy properties of the atoms strongly dependent on the initial state of the system and the average photon number. Detuning, coupling constant between the atoms and the Kerr coefficient still make influence on the information entropy of the atoms. (authors)

  10. Effects of the electron-electron interaction in the spin resonance in 2D systems with Dresselhaus spin-orbit coupling

    International Nuclear Information System (INIS)

    Krishtopenko, S. S.

    2015-01-01

    The effect of the electron-electron interaction on the spin-resonance frequency in two-dimensional electron systems with Dresselhaus spin-orbit coupling is investigated. The oscillatory dependence of many-body corrections on the magnetic field is demonstrated. It is shown that the consideration of many-body interaction leads to a decrease or an increase in the spin-resonance frequency, depending on the sign of the g factor. It is found that the term cubic in quasimomentum in Dresselhaus spin-orbit coupling partially decreases exchange corrections to the spin resonance energy in a two-dimensional system

  11. Effects of the electron-electron interaction in the spin resonance in 2D systems with Dresselhaus spin-orbit coupling

    Energy Technology Data Exchange (ETDEWEB)

    Krishtopenko, S. S., E-mail: sergey.krishtopenko@mail.ru [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

    2015-02-15

    The effect of the electron-electron interaction on the spin-resonance frequency in two-dimensional electron systems with Dresselhaus spin-orbit coupling is investigated. The oscillatory dependence of many-body corrections on the magnetic field is demonstrated. It is shown that the consideration of many-body interaction leads to a decrease or an increase in the spin-resonance frequency, depending on the sign of the g factor. It is found that the term cubic in quasimomentum in Dresselhaus spin-orbit coupling partially decreases exchange corrections to the spin resonance energy in a two-dimensional system.

  12. Phase-Amplitude Coupling and Long-Range Phase Synchronization Reveal Frontotemporal Interactions during Visual Working Memory.

    Science.gov (United States)

    Daume, Jonathan; Gruber, Thomas; Engel, Andreas K; Friese, Uwe

    2017-01-11

    It has been suggested that cross-frequency phase-amplitude coupling (PAC), particularly in temporal brain structures, serves as a neural mechanism for coordinated working memory storage. In this magnetoencephalography study, we show that during visual working memory maintenance, temporal cortex regions, which exhibit enhanced PAC, interact with prefrontal cortex via enhanced low-frequency phase synchronization. Healthy human participants were engaged in a visual delayed match-to-sample task with pictures of natural objects. During the delay period, we observed increased spectral power of beta (20-28 Hz) and gamma (40-94 Hz) bands as well as decreased power of theta/alpha band (7-9 Hz) oscillations in visual sensory areas. Enhanced PAC between the phases of theta/alpha and the amplitudes of beta oscillations was found in the left inferior temporal cortex (IT), an area known to be involved in visual object memory. Furthermore, the IT was functionally connected to the prefrontal cortex by increased low-frequency phase synchronization within the theta/alpha band. Together, these results point to a mechanism in which the combination of PAC and long-range phase synchronization subserves enhanced large-scale brain communication. They suggest that distant brain regions might coordinate their activity in the low-frequency range to engage local stimulus-related processing in higher frequencies via the combination of long-range, within-frequency phase synchronization and local cross-frequency PAC. Working memory maintenance, like other cognitive functions, requires the coordinated engagement of brain areas in local and large-scale networks. However, the mechanisms by which spatially distributed brain regions share and combine information remain primarily unknown. We show that the combination of long-range, low-frequency phase synchronization and local cross-frequency phase-amplitude coupling might serve as a mechanism to coordinate memory processes across distant brain areas

  13. The influence of laser-particle interaction in laser induced breakdown spectroscopy and laser ablation inductively coupled plasma spectrometry

    International Nuclear Information System (INIS)

    Lindner, Helmut; Loper, Kristofer H.; Hahn, David W.; Niemax, Kay

    2011-01-01

    Particles produced by previous laser shots may have significant influence on the analytical signal in laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma (LA-ICP) spectrometry if they remain close to the position of laser sampling. The effects of these particles on the laser-induced breakdown event are demonstrated in several ways. LIBS-experiments were conducted in an ablation cell at atmospheric conditions in argon or air applying a dual-pulse arrangement with orthogonal pre-pulse, i.e., plasma breakdown in a gas generated by a focussed laser beam parallel and close to the sample surface followed by a delayed crossing laser pulse in orthogonal direction which actually ablates material from the sample and produces the LIBS plasma. The optical emission of the LIBS plasma as well as the absorption of the pre-pulse laser was measured. In the presence of particles in the focus of the pre-pulse laser, the plasma breakdown is affected and more energy of the pre-pulse laser is absorbed than without particles. As a result, the analyte line emission from the LIBS plasma of the second laser is enhanced. It is assumed that the enhancement is not only due to an increase of mass ablated by the second laser but also to better atomization and excitation conditions favored by a reduced gas density in the pre-pulse plasma. Higher laser pulse frequencies increase the probability of particle-laser interaction and, therefore, reduce the shot-to-shot line intensity variation as compared to lower particle loadings in the cell. Additional experiments using an aerosol chamber were performed to further quantify the laser absorption by the plasma in dependence on time both with and without the presence of particles. The overall implication of laser-particle interactions for LIBS and LA-ICP-MS/OES are discussed.

  14. Functional Selectivity of Allosteric Interactions within G Protein–Coupled Receptor Oligomers: The Dopamine D1-D3 Receptor Heterotetramer

    Science.gov (United States)

    Guitart, Xavier; Navarro, Gemma; Moreno, Estefania; Yano, Hideaki; Cai, Ning-Sheng; Sánchez-Soto, Marta; Kumar-Barodia, Sandeep; Naidu, Yamini T.; Mallol, Josefa; Cortés, Antoni; Lluís, Carme; Canela, Enric I.; Casadó, Vicent; McCormick, Peter J.

    2014-01-01

    The dopamine D1 receptor–D3 receptor (D1R-D3R) heteromer is being considered as a potential therapeutic target for neuropsychiatric disorders. Previous studies suggested that this heteromer could be involved in the ability of D3R agonists to potentiate locomotor activation induced by D1R agonists. It has also been postulated that its overexpression plays a role in L-dopa–induced dyskinesia and in drug addiction. However, little is known about its biochemical properties. By combining bioluminescence resonance energy transfer, bimolecular complementation techniques, and cell-signaling experiments in transfected cells, evidence was obtained for a tetrameric stoichiometry of the D1R–D3R heteromer, constituted by two interacting D1R and D3R homodimers coupled to Gs and Gi proteins, respectively. Coactivation of both receptors led to the canonical negative interaction at the level of adenylyl cyclase signaling, to a strong recruitment of β-arrestin-1, and to a positive cross talk of D1R and D3R agonists at the level of mitogen-activated protein kinase (MAPK) signaling. Furthermore, D1R or D3R antagonists counteracted β-arrestin-1 recruitment and MAPK activation induced by D3R and D1R agonists, respectively (cross-antagonism). Positive cross talk and cross-antagonism at the MAPK level were counteracted by specific synthetic peptides with amino acid sequences corresponding to D1R transmembrane (TM) domains TM5 and TM6, which also selectively modified the quaternary structure of the D1R-D3R heteromer, as demonstrated by complementation of hemiproteins of yellow fluorescence protein fused to D1R and D3R. These results demonstrate functional selectivity of allosteric modulations within the D1R-D3R heteromer, which can be involved with the reported behavioral synergism of D1R and D3R agonists. PMID:25097189

  15. The influence of laser-particle interaction in laser induced breakdown spectroscopy and laser ablation inductively coupled plasma spectrometry

    Science.gov (United States)

    Lindner, Helmut; Loper, Kristofer H.; Hahn, David W.; Niemax, Kay

    2011-02-01

    Particles produced by previous laser shots may have significant influence on the analytical signal in laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma (LA-ICP) spectrometry if they remain close to the position of laser sampling. The effects of these particles on the laser-induced breakdown event are demonstrated in several ways. LIBS-experiments were conducted in an ablation cell at atmospheric conditions in argon or air applying a dual-pulse arrangement with orthogonal pre-pulse, i.e., plasma breakdown in a gas generated by a focussed laser beam parallel and close to the sample surface followed by a delayed crossing laser pulse in orthogonal direction which actually ablates material from the sample and produces the LIBS plasma. The optical emission of the LIBS plasma as well as the absorption of the pre-pulse laser was measured. In the presence of particles in the focus of the pre-pulse laser, the plasma breakdown is affected and more energy of the pre-pulse laser is absorbed than without particles. As a result, the analyte line emission from the LIBS plasma of the second laser is enhanced. It is assumed that the enhancement is not only due to an increase of mass ablated by the second laser but also to better atomization and excitation conditions favored by a reduced gas density in the pre-pulse plasma. Higher laser pulse frequencies increase the probability of particle-laser interaction and, therefore, reduce the shot-to-shot line intensity variation as compared to lower particle loadings in the cell. Additional experiments using an aerosol chamber were performed to further quantify the laser absorption by the plasma in dependence on time both with and without the presence of particles. The overall implication of laser-particle interactions for LIBS and LA-ICP-MS/OES are discussed.

  16. Rapid quantification of underivatized amino acids in plasma by hydrophilic interaction liquid chromatography (HILIC) coupled with tandem mass-spectrometry.

    Science.gov (United States)

    Prinsen, Hubertus C M T; Schiebergen-Bronkhorst, B G M; Roeleveld, M W; Jans, J J M; de Sain-van der Velden, M G M; Visser, G; van Hasselt, P M; Verhoeven-Duif, N M

    2016-09-01

    Amino acidopathies are a class of inborn errors of metabolism (IEM) that can be diagnosed by analysis of amino acids (AA) in plasma. Current strategies for AA analysis include cation exchange HPLC with post-column ninhydrin derivatization, GC-MS, and LC-MS/MS-related methods. Major drawbacks of the current methods are time-consuming procedures, derivative problems, problems with retention, and MS-sensitivity. The use of hydrophilic interaction liquid chromatography (HILIC) columns is an ideal separation mode for hydrophilic compounds like AA. Here we report a HILIC-method for analysis of 36 underivatized AA in plasma to detect defects in AA metabolism that overcomes the major drawbacks of other methods. A rapid, sensitive, and specific method was developed for the analysis of AA in plasma without derivatization using HILIC coupled with tandem mass-spectrometry (Xevo TQ, Waters). Excellent separation of 36 AA (24 quantitative/12 qualitative) in plasma was achieved on an Acquity BEH Amide column (2.1×100 mm, 1.7 μm) in a single MS run of 18 min. Plasma of patients with a known IEM in AA metabolism was analyzed and all patients were correctly identified. The reported method analyzes 36 AA in plasma within 18 min and provides baseline separation of isomeric AA such as leucine and isoleucine. No separation was obtained for isoleucine and allo-isoleucine. The method is applicable to study defects in AA metabolism in plasma.

  17. PISCES 3DELK - a coupled Euler/Lagrange program for computing dynamic fluid-structure interactions in three dimensions

    International Nuclear Information System (INIS)

    Chu, H.Y.; Cowler, M.S.; Hancock, H.

    1983-01-01

    This paper describes the main features of PISCES 3DELK, a computer code that is used to solve complex three-dimensional fluid-structure interaction problems in reactor safety. These features include: an Eulerian finite difference scheme for calculating fluid flow and large distortions of solid media; a Langrange finite element scheme for calculating the response of thin structures; coupling of the Euler and Langrange schemes at fluid-structure interfaces. The code has been well validated and applied to a number of reactor safety analyses including blowdown in reactor primary vessels and components, and loadings on the secondary containment caused by a breach in the primary containment. Details of two analyses are presented in this paper. The first analysis is of blowdown in a pressurized water reactor caused by a cold leg break (the HDR experiment). Results of the PISCES 3DELK calculation are compared with results obtained by the K-FIX code. Agreement between the two calculations is good. The second analysis is of the depressurization caused by a feedwater pipe break in a steam generator of the CANDU reactor. Calculations have been performed which show that flexibility of internal components in the heat exchanger mitigate structural loadings. (orig.)

  18. Measurement of the strong interaction coupling constant αs by jet study in the H1 experiment

    International Nuclear Information System (INIS)

    Squinabol, F.

    1997-01-01

    The H1 experiment allows to study hadronic jets produced in deep inelastic lepton (27.5 GeV) scattering off protons (820 GeV). The coupling constant of the strong interaction α s can be extracted from the measurement of the 2-jets rate in the final state. The use of the JADE algorithm is optimal for events with high energy transfer (100-4,000 GeV 2 ), corresponding to the 1994 and 1995 data. The error on α s (M Z 0 2 ) is dominated by the uncertainty from the hadronic energy measurement and the experimental resolution effects on jets. The theoretical error is dominated by the renormalization scale dependence. The final result is (M Z 0 2 ) 0.118 -0.008 +0.008 . This analysis is extended to smaller momentum transfers (25-100 GeV 2 ) using the factorizable K t algorithm, taking the transferred momentum as energy scale of the particle re-clustering. The result α s (M Z 0 2 ) 0.117 -0.008 +0.009 is compatible with the previous one. The precision of the measurement performed in this thesis is 7%. A precision of 4% could be achieved after progresses in the theoretical framework and/or after a significant increase of the luminosity. (author)

  19. Ultrasonic microdialysis coupled with capillary electrophoresis electrochemiluminescence study the interaction between trimetazidine dihydrochloride and human serum albumin.

    Science.gov (United States)

    Sun, Shuangjiao; Long, Chanjuan; Tao, Chunyao; Meng, Sa; Deng, Biyang

    2014-12-03

    The paper describes a homemade ultrasonic microdialysis device coupled with capillary electrophoresis electrochemiluminescence (CE-ECL) for studying the interaction between human serum albumin (HSA) and trimetazidine dihydrochloride (TMZ). The time required for equilibrium by ultrasonic microdialysis was 45min, which was far less than that by traditional dialysis (240min). It took 80min to achieve the required combination equilibrium by normal incubation and only 20min by ultrasonic. Compared with traditional dialysis, the use of ultrasonic microdialysis simplified experimental procedures, shortened experimental time and saved consumption of sample. A simple, sensitive and selective determination of TMZ was developed using CE-ECL and the parameters that affected ECL intensity were optimized. Under the optimized conditions, the linear range of TMZ was from 0.075 to 80μmol/L (r(2)=0.9974). The detection limit was 26nmol/L with RSD of 2.8%. The number of binding sites and binding constant were 1.54 and 15.17L/mol, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Collective excitations with chiral NN+3N interactions from coupled-cluster and in-medium SRG

    International Nuclear Information System (INIS)

    Trippel, Richard

    2016-01-01

    A broad variety of many-body methods exists for the investigation of ground-state properties, ranging from sophisticated ab initio approaches to traditional, phenomenological models. The description of low-lying excited states of medium-mass nuclei with ab initio methods has also become possible through recent progress in many-body theory. For collective modes at higher energies, however, these methods usually cannot be applied. Therefore, when describing collective excitations either completely phenomenological, macroscopic models are employed or microscopic models using phenomenological interactions. One of the microscopic models well suited for the calculation of collective properties is the random-phase approximation (RPA). In the past, the use of phenomenological interactions for RPA has shown promising results. However, the application of chiral NN interactions yielded transitions at significantly too high energies, far from agreement with experimental data. This thesis focuses on the description of collective modes using both RPA and its second-order extension, SRPA. In contrast to previous research endeavors, we employ chiral NN+3N interactions. The use of chiral interactions is an important first step for describing ground-state, excitation and collective properties on an equal foundation. We find that the inclusion of 3N terms is crucial for RPA calculations and the prediction for collective modes is drastically improved through the 3N terms. For SRPA we show first-ever results with chiral interactions, again leading to an improvement in the predictions. For a successful ab initio description of ground-state properties the inclusion of correlations is of paramount importance. Past RPA calculations have been performed using the quasi-boson approximation, effectively neglecting ground-state correlations. Using RPA, the next step along the path towards an ab initio description of collective properties will, therefore, be the inclusion of correlations. To

  1. Collective excitations with chiral NN+3N interactions from coupled-cluster and in-medium SRG

    Energy Technology Data Exchange (ETDEWEB)

    Trippel, Richard

    2016-12-19

    A broad variety of many-body methods exists for the investigation of ground-state properties, ranging from sophisticated ab initio approaches to traditional, phenomenological models. The description of low-lying excited states of medium-mass nuclei with ab initio methods has also become possible through recent progress in many-body theory. For collective modes at higher energies, however, these methods usually cannot be applied. Therefore, when describing collective excitations either completely phenomenological, macroscopic models are employed or microscopic models using phenomenological interactions. One of the microscopic models well suited for the calculation of collective properties is the random-phase approximation (RPA). In the past, the use of phenomenological interactions for RPA has shown promising results. However, the application of chiral NN interactions yielded transitions at significantly too high energies, far from agreement with experimental data. This thesis focuses on the description of collective modes using both RPA and its second-order extension, SRPA. In contrast to previous research endeavors, we employ chiral NN+3N interactions. The use of chiral interactions is an important first step for describing ground-state, excitation and collective properties on an equal foundation. We find that the inclusion of 3N terms is crucial for RPA calculations and the prediction for collective modes is drastically improved through the 3N terms. For SRPA we show first-ever results with chiral interactions, again leading to an improvement in the predictions. For a successful ab initio description of ground-state properties the inclusion of correlations is of paramount importance. Past RPA calculations have been performed using the quasi-boson approximation, effectively neglecting ground-state correlations. Using RPA, the next step along the path towards an ab initio description of collective properties will, therefore, be the inclusion of correlations. To

  2. Analysis of the interactions between difluoroacetylene and one or two hydrogen fluoride molecules based on calculated spin–spin coupling constants

    DEFF Research Database (Denmark)

    Provasi, Patricio F.; Caputo, María Cristina; Sauer, Stephan P. A.

    2012-01-01

    A theoretical study of FCCF:(HF)n complexes, with n = 1 and 2, has been carried out by means of ab initio computational methods. Two types of complexes are formed: those with FH···p interactions and those with FH···FC hydrogen bonds. The indirect spin–spin coupling constants have been calculated ...

  3. A method for studies on interactions between a gold-based drug and plasma proteins based on capillary electrophoresis with inductively coupled plasma mass spectrometry detection

    DEFF Research Database (Denmark)

    Nguyen, Tam T T N; Østergaard, Jesper; Gammelgaard, Bente

    2015-01-01

    An analytical method based on capillary electrophoresis (CE) and inductively coupled plasma mass spectrometry (ICP-MS) detection was developed for studies on the interaction of gold-containing drugs and plasma proteins using auranofin as example. A detection limit of 18 ng/mL of auranofin corresp...

  4. [Coupled Analysis of Fluid-Structure Interaction of a Micro-Mechanical Valve for Glaucoma Drainage Devices].

    Science.gov (United States)

    Siewert, S; Sämann, M; Schmidt, W; Stiehm, M; Falke, K; Grabow, N; Guthoff, R; Schmitz, K-P

    2015-12-01

    Glaucoma is the leading cause of irreversible blindness worldwide. In therapeutically refractory cases, alloplastic glaucoma drainage devices (GDD) are being increasingly used to decrease intraocular pressure. Current devices are mainly limited by fibrotic encapsulation and postoperative hypotension. Preliminary studies have described the development of a glaucoma microstent to control aqueous humour drainage from the anterior chamber into the suprachoroidal space. One focus of these studies was on the design of a micro-mechanical valve placed in the anterior chamber to inhibit postoperative hypotension. The present report describes the coupled analysis of fluid-structure interaction (FSI) as basis for future improvements in the design micro-mechanical valves. FSI analysis was carried out with ANSYS 14.5 software. Solid and fluid geometry were combined in a model, and the corresponding material properties of silicone (Silastic Rx-50) and water at room temperature were assigned. The meshing of the solid and fluid domains was carried out in accordance with the results of a convergence study with tetrahedron elements. Structural and fluid mechanical boundary conditions completed the model. The FSI analysis takes into account geometric non-linearity and adaptive remeshing to consider changing geometry. A valve opening pressure of 3.26 mmHg was derived from the FSI analysis and correlates well with the results of preliminary experimental fluid mechanical studies. Flow resistance was calculated from non-linear pressure-flow characteristics as 8.5 × 10(-3) mmHg/µl  · min(-1) and 2.7 × 10(-3) mmHg/µl  · min(-1), respectively before and after valve opening pressure is exceeded. FSI analysis indicated leakage flow before valve opening, which is due to the simplified model geometry. The presented bidirectional coupled FSI analysis is a powerful tool for the development of new designs of micro-mechanical valves for GDD and may help to minimise the time and cost

  5. Integration of prognostic aerosol-cloud interactions in a chemistry transport model coupled offline to a regional climate model

    Science.gov (United States)

    Thomas, M. A.; Kahnert, M.; Andersson, C.; Kokkola, H.; Hansson, U.; Jones, C.; Langner, J.; Devasthale, A.

    2015-06-01

    To reduce uncertainties and hence to obtain a better estimate of aerosol (direct and indirect) radiative forcing, next generation climate models aim for a tighter coupling between chemistry transport models and regional climate models and a better representation of aerosol-cloud interactions. In this study, this coupling is done by first forcing the Rossby Center regional climate model (RCA4) with ERA-Interim lateral boundaries and sea surface temperature (SST) using the standard cloud droplet number concentration (CDNC) formulation (hereafter, referred to as the "stand-alone RCA4 version" or "CTRL" simulation). In the stand-alone RCA4 version, CDNCs are constants distinguishing only between land and ocean surface. The meteorology from this simulation is then used to drive the chemistry transport model, Multiple-scale Atmospheric Transport and Chemistry (MATCH), which is coupled online with the aerosol dynamics model, Sectional Aerosol module for Large Scale Applications (SALSA). CDNC fields obtained from MATCH-SALSA are then fed back into a new RCA4 simulation. In this new simulation (referred to as "MOD" simulation), all parameters remain the same as in the first run except for the CDNCs provided by MATCH-SALSA. Simulations are carried out with this model setup for the period 2005-2012 over Europe, and the differences in cloud microphysical properties and radiative fluxes as a result of local CDNC changes and possible model responses are analysed. Our study shows substantial improvements in cloud microphysical properties with the input of the MATCH-SALSA derived 3-D CDNCs compared to the stand-alone RCA4 version. This model setup improves the spatial, seasonal and vertical distribution of CDNCs with a higher concentration observed over central Europe during boreal summer (JJA) and over eastern Europe and Russia during winter (DJF). Realistic cloud droplet radii (CD radii) values have been simulated with the maxima reaching 13 μm, whereas in the stand

  6. Functional selectivity of allosteric interactions within G protein-coupled receptor oligomers: the dopamine D1-D3 receptor heterotetramer.

    Science.gov (United States)

    Guitart, Xavier; Navarro, Gemma; Moreno, Estefania; Yano, Hideaki; Cai, Ning-Sheng; Sánchez-Soto, Marta; Kumar-Barodia, Sandeep; Naidu, Yamini T; Mallol, Josefa; Cortés, Antoni; Lluís, Carme; Canela, Enric I; Casadó, Vicent; McCormick, Peter J; Ferré, Sergi

    2014-10-01

    The dopamine D1 receptor-D3 receptor (D1R-D3R) heteromer is being considered as a potential therapeutic target for neuropsychiatric disorders. Previous studies suggested that this heteromer could be involved in the ability of D3R agonists to potentiate locomotor activation induced by D1R agonists. It has also been postulated that its overexpression plays a role in L-dopa-induced dyskinesia and in drug addiction. However, little is known about its biochemical properties. By combining bioluminescence resonance energy transfer, bimolecular complementation techniques, and cell-signaling experiments in transfected cells, evidence was obtained for a tetrameric stoichiometry of the D1R-D3R heteromer, constituted by two interacting D1R and D3R homodimers coupled to Gs and Gi proteins, respectively. Coactivation of both receptors led to the canonical negative interaction at the level of adenylyl cyclase signaling, to a strong recruitment of β-arrestin-1, and to a positive cross talk of D1R and D3R agonists at the level of mitogen-activated protein kinase (MAPK) signaling. Furthermore, D1R or D3R antagonists counteracted β-arrestin-1 recruitment and MAPK activation induced by D3R and D1R agonists, respectively (cross-antagonism). Positive cross talk and cross-antagonism at the MAPK level were counteracted by specific synthetic peptides with amino acid sequences corresponding to D1R transmembrane (TM) domains TM5 and TM6, which also selectively modified the quaternary structure of the D1R-D3R heteromer, as demonstrated by complementation of hemiproteins of yellow fluorescence protein fused to D1R and D3R. These results demonstrate functional selectivity of allosteric modulations within the D1R-D3R heteromer, which can be involved with the reported behavioral synergism of D1R and D3R agonists. U.S. Government work not protected by U.S. copyright.

  7. Modeling coupled interactions of carbon, water, and ozone exchange between terrestrial ecosystems and the atmosphere. I: Model description

    International Nuclear Information System (INIS)

    Nikolov, Ned; Zeller, Karl F.

    2003-01-01

    A new biophysical model (FORFLUX) is presented to link ozone deposition with carbon and water cycles in terrestrial ecosystems. - A new biophysical model (FORFLUX) is presented to study the simultaneous exchange of ozone, carbon dioxide, and water vapor between terrestrial ecosystems and the atmosphere. The model mechanistically couples all major processes controlling ecosystem flows trace gases and water implementing recent concepts in plant eco-physiology, micrometeorology, and soil hydrology. FORFLUX consists of four interconnected modules-a leaf photosynthesis model, a canopy flux model, a soil heat-, water- and CO 2 - transport model, and a snow pack model. Photosynthesis, water-vapor flux and ozone uptake at the leaf level are computed by the LEAFC3 sub-model. The canopy module scales leaf responses to a stand level by numerical integration of the LEAFC3 model over canopy leaf area index (LAI). The integration takes into account (1) radiative transfer inside the canopy, (2) variation of foliage photosynthetic capacity with canopy depth, (3) wind speed attenuation throughout the canopy, and (4) rainfall interception by foliage elements. The soil module uses principles of the diffusion theory to predict temperature and moisture dynamics within the soil column, evaporation, and CO 2 efflux from soil. The effect of soil heterogeneity on field-scale fluxes is simulated employing the Bresler-Dagan stochastic concept. The accumulation and melt of snow on the ground is predicted using an explicit energy balance approach. Ozone deposition is modeled as a sum of three fluxes- ozone uptake via plant stomata, deposition to non-transpiring plant surfaces, and ozone flux into the ground. All biophysical interactions are computed hourly while model projections are made at either hourly or daily time step. FORFLUX represents a comprehensive approach to studying ozone deposition and its link to carbon and water cycles in terrestrial ecosystems

  8. New type of chimera and mutual synchronization of spatiotemporal structures in two coupled ensembles of nonlocally interacting chaotic maps

    Science.gov (United States)

    Bukh, Andrei; Rybalova, Elena; Semenova, Nadezhda; Strelkova, Galina; Anishchenko, Vadim

    2017-11-01

    We study numerically the dynamics of a network made of two coupled one-dimensional ensembles of discrete-time systems. The first ensemble is represented by a ring of nonlocally coupled Henon maps and the second one by a ring of nonlocally coupled Lozi maps. We find that the network of coupled ensembles can realize all the spatio-temporal structures which are observed both in the Henon map ensemble and in the Lozi map ensemble while uncoupled. Moreover, we reveal a new type of spatiotemporal structure, a solitary state chimera, in the considered network. We also establish and describe the effect of mutual synchronization of various complex spatiotemporal patterns in the system of two coupled ensembles of Henon and Lozi maps.

  9. Electron-phonon coupling and superconductivity in the (4/3)-monolayer of Pb on Si(111): Role of spin-orbit interaction

    Science.gov (United States)

    Sklyadneva, I. Yu.; Heid, R.; Bohnen, K.-P.; Echenique, P. M.; Chulkov, E. V.

    2018-05-01

    The effect of spin-orbit coupling on the electron-phonon interaction in a (4/3)-monolayer of Pb on Si(111) is investigated within the density-functional theory and linear-response approach in the mixed-basis pseudopotential representation. We show that the spin-orbit interaction produces a large weakening of the electron-phonon coupling strength, which appears to be strongly overestimated in the scalar relativistic calculations. The effect of spin-orbit interaction is largely determined by the induced modification of Pb electronic bands and a stiffening of the low-energy part of phonon spectrum, which favor a weakening of the electron-phonon coupling strength. The state-dependent strength of the electron-phonon interaction in occupied Pb electronic bands varies depending on binding energy rather than electronic momentum. It is markedly larger than the value averaged over electron momentum because substrate electronic bands make a small contribution to the phonon-mediated scattering and agrees well with the experimental data.

  10. Density of states and phase diagram of the antiferromagnetic spin chain with Dzyaloshinsky-Moriya interaction and spin-phonon coupling

    International Nuclear Information System (INIS)

    Wang Qin; Chen Hong; Zheng Hang

    2007-01-01

    The effects of DM interaction on the density-of-states, the dimerization and the phase diagram in the antiferromagnetic Heisenberg chain coupled with quantum phonons have been studied by a nonadiabatic analytical approach. The results show that the effect of the DM interaction is to increase the staggered antisymmetric spin exchange interaction order but to decrease the spin dimerization and their competitions result in the lattice dimerization ordering parameter to increase for large staggered DM interaction parameter β and decrease for small β. A crossover of β exists in which the dimerization ordering parameter changes non-monotonously. As the DM interaction parameter D increases, depending on the appropriate values of spin-phonon coupling, phonon frequency and β, the system undergoes phase transition from spin gapless state to gapped state or reversely and can even reenter between the two states. The relation between the phonon-staggered ordering parameter, the spin-dimer order parameter and the staggered DM interaction order parameter gives clearly their contributing weights to the lattice dimerization

  11. Investigation of metallodrug-protein interactions by size-exclusion chromatography coupled with inductively coupled plasma mass spectrometry (ICP-MS)

    International Nuclear Information System (INIS)

    Szpunar, J.; Makarov, A.; Pieper, T.; Keppler, B.K.; Lobinski, R.

    1999-01-01

    The coupling of size-exclusion HPLC with ICP-MS was developed for the studies of the kinetics of metallodrug binding to human serum proteins. Two platinum- and three ruthenium-based drugs were investigated. Various SEC columns (of different lengths and with different packings) were compared for the separation of the protein-bound and unbound fractions of a metallodrug prior to on-line detection of the metal (Ru or Pt). The approach developed offers considerable advantages over the methods based on ultrafiltration followed by the off-line metal determination in terms of speed, simplicity, precision and selectivity regarding the molecular weight of the complexes involved. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  12. Inter-cluster coupling effects in high-spin molecular magnets

    International Nuclear Information System (INIS)

    Affronte, M.; Lasjaunias, J.C.; Wernsdorfer, W.; Sessoli, R.; Gatteschi, D.; Heath, S.L.; Fort, A.; Rettori, A.

    2004-01-01

    We report evidences of antiferromagnetic (AF) transition in Fe 19 metheidi, a new molecular nanomagnet with a total spin S=((33)/(2)), among the highest known so far. The temperature (T) dependence of specific heat (C) shows a λ-anomaly at 1.19 K and at the same temperature an anomaly is also observed in the low field (B<0.12 T) magnetization M-vs.-T curves. Since the dipolar interaction between clusters is estimated to be ∼190 mK, the origin of the AF transition is probably due to superexchange

  13. Inter-cluster coupling effects in high-spin molecular magnets

    Energy Technology Data Exchange (ETDEWEB)

    Affronte, M.; Lasjaunias, J.C.; Wernsdorfer, W.; Sessoli, R.; Gatteschi, D.; Heath, S.L.; Fort, A. E-mail: fort@fi.infn.it; Rettori, A

    2004-05-01

    We report evidences of antiferromagnetic (AF) transition in Fe{sub 19}metheidi, a new molecular nanomagnet with a total spin S=((33)/(2)), among the highest known so far. The temperature (T) dependence of specific heat (C) shows a {lambda}-anomaly at 1.19 K and at the same temperature an anomaly is also observed in the low field (B<0.12 T) magnetization M-vs.-T curves. Since the dipolar interaction between clusters is estimated to be {approx}190 mK, the origin of the AF transition is probably due to superexchange.

  14. Systematic evaluation of matrix effects in hydrophilic interaction chromatography versus reversed phase liquid chromatography coupled to mass spectrometry.

    Science.gov (United States)

    Periat, Aurélie; Kohler, Isabelle; Thomas, Aurélien; Nicoli, Raul; Boccard, Julien; Veuthey, Jean-Luc; Schappler, Julie; Guillarme, Davy

    2016-03-25

    Reversed phase liquid chromatography (RPLC) coupled to mass spectrometry (MS) is the gold standard technique in bioanalysis. However, hydrophilic interaction chromatography (HILIC) could represent a viable alternative to RPLC for the analysis of polar and/or ionizable compounds, as it often provides higher MS sensitivity and alternative selectivity. Nevertheless, this technique can be also prone to matrix effects (ME). ME are one of the major issues in quantitative LC-MS bioanalysis. To ensure acceptable method performance (i.e., trueness and precision), a careful evaluation and minimization of ME is required. In the present study, the incidence of ME in HILIC-MS/MS and RPLC-MS/MS was compared for plasma and urine samples using two representative sets of 38 pharmaceutical compounds and 40 doping agents, respectively. The optimal generic chromatographic conditions in terms of selectivity with respect to interfering compounds were established in both chromatographic modes by testing three different stationary phases in each mode with different mobile phase pH. A second step involved the assessment of ME in RPLC and HILIC under the best generic conditions, using the post-extraction addition method. Biological samples were prepared using two different sample pre-treatments, i.e., a non-selective sample clean-up procedure (protein precipitation and simple dilution for plasma and urine samples, respectively) and a selective sample preparation, i.e., solid phase extraction for both matrices. The non-selective pretreatments led to significantly less ME in RPLC vs. HILIC conditions regardless of the matrix. On the contrary, HILIC appeared as a valuable alternative to RPLC for plasma and urine samples treated by a selective sample preparation. Indeed, in the case of selective sample preparation, the compounds influenced by ME were different in HILIC and RPLC, and lower and similar ME occurrence was generally observed in RPLC vs. HILIC for urine and plasma samples

  15. Recent advances in on-line coupling of capillary electrophoresis to atomic absorption and fluorescence spectrometry for speciation analysis and studies of metal-biomolecule interactions

    International Nuclear Information System (INIS)

    Li Yan; Yin Xuebo; Yan Xiuping

    2008-01-01

    Speciation information is vital for the understanding of the toxicity, mobility and bioavailability of elements in environmental or biological samples. Hyphenating high resolving power of separation techniques and element-selective detectors provides powerful tools for studying speciation of trace elements in environmental and biological systems. During the last five years several novel hybrid techniques based on capillary electrophoresis (CE) and atomic spectrometry have been developed for speciation analysis and metal-biomolecule interaction study in our laboratory. These techniques include CE on-line coupled with atomic fluorescence spectrometry (AFS), chip-CE on-line coupled with AFS, CE on-line coupled with flame heated quartz furnace atomic absorption spectrometry (FHF-AAS), and CE on-line coupled with electrothermal atomic absorption spectrometry (ETAAS). The necessity for the development of these techniques, their interface design, and applications in speciation analysis and metal-biomolecule interaction study are reviewed. The advantages and limitations of the developed hybrid techniques are critically discussed, and further development is also prospected

  16. Two- and four-quasiparticle states in the interacting boson model: Strong-coupling and decoupled band patterns in the SU(3) limit

    International Nuclear Information System (INIS)

    Vretenar, D.; Paar, V.; Bonsignori, G.; Savoia, M.

    1990-01-01

    An extension of the interacting boson approximation model is proposed by allowing for two- and four-quasiparticle excitations out of the boson space. The formation of band patterns based on two- and four-quasiparticle states is investigated in the SU(3) limit of the model. For hole-type (particle-type) fermions coupled to the SU(3) prolate (oblate) core, it is shown that the algebraic K-representation basis, which is the analog of the strong-coupling basis of the geometrical model, provides an appropriate description of the low-lying two-quasiparticle bands. In the case of particle-type (hole-type) fermions coupled to the SU(3) prolate (oblate) core, a new algebraic decoupling basis is derived that is equivalent in the geometrical limit to Stephens' rotation-aligned basis. Comparing the wave functions that are obtained by diagonalization of the model Hamiltonian to the decoupling basis, several low-lying two-quasiparticle bands are identified. The effects of an interaction that conserves only the total nucleon number, mixing states with different number of fermions, are investigated in both the strong-coupling and decoupling limits. All calculations are performed for an SU(3) boson core and the h11/2 fermion orbital

  17. Two-dimensional solitons and quantum droplets supported by competing self- and cross-interactions in spin-orbit-coupled condensates

    Science.gov (United States)

    Li, Yongyao; Luo, Zhihuan; Liu, Yan; Chen, Zhaopin; Huang, Chunqing; Fu, Shenhe; Tan, Haishu; Malomed, Boris A.

    2017-11-01

    We study two-dimensional (2D) matter-wave solitons in spinor Bose-Einstein condensates under the action of the spin-orbit coupling and opposite signs of the self- and cross-interactions. Stable 2D two-component solitons of the mixed-mode type are found if the cross-interaction between the components is attractive, while the self-interaction is repulsive in each component. Stable solitons of the semi-vortex type are formed in the opposite case, under the action of competing self-attraction and cross-repulsion. The solitons exist with the total norm taking values below a collapse threshold. Further, in the case of the repulsive self-interaction and inter-component attraction, stable 2D self-trapped modes, which may be considered as quantum droplets (QDs), are created if the beyond-mean-field Lee-Huang-Yang terms are added to the self-repulsion in the underlying system of coupled Gross-Pitaevskii equations. Stable QDs of the mixed-mode type, of a large size with an anisotropic density profile, exist with arbitrarily large values of the norm, as the Lee-Huang-Yang terms eliminate the collapse. The effect of the spin-orbit coupling term on characteristics of the QDs is systematically studied. We also address the existence and stability of QDs in the case of SOC with mixed Rashba and Dresselhaus terms, which makes the density profile of the QD more isotropic. Thus, QDs in the spin-orbit-coupled binary Bose-Einstein condensate are for the first time studied in the present work.

  18. The role of ocean-atmosphere interaction in Typhoon Sinlaku (2008) using a regional coupled data assimilation system

    Science.gov (United States)

    Wada, Akiyoshi; Kunii, Masaru

    2017-05-01

    For improving analyses of tropical cyclone (TC) and sea surface temperature (SST) and thereby TC simulations, a regional mesoscale strongly coupled atmosphere-ocean data assimilation system was developed with the local ensemble transform Kalman filter (LETKF) implemented with the Japan Meteorological Agency's nonhydrostatic model (NHM) coupled with a multilayer ocean model and the third-generation ocean wave model. The NHM-LETKF coupled data assimilation system was applied to Typhoon Sinlaku (2008) along with the original NHM-LETKF system to investigate the sensitivity of Sinlaku to SST assimilation with the Level 2 Pre-processed (L2P) standard product of satellite SST. SST calculated in the coupled-assimilation experiment with the coupled data assimilation system and the satellite SST (CPL) showed a better correlation with Optimally Interpolated SST than SST used in the control experiment with the original NHM-LETKF (CNTL) and SST calculated in the succession experiment with the coupled system without satellite SST (SUCC). The time series in the CPL experiment well captured the variation in the SST observed at the Kuroshio Extension Observation buoy site. In addition, TC-induced sea surface cooling was analyzed more realistically in the CPL experiment than that in the CNTL and SUCC experiments. However, the central pressure analyzed in each three experiments was overestimated compared with the Regional Specialized Meteorological Center Tokyo best-track central pressure, mainly due to the coarse horizontal resolution of 15 km. The 96 h TC simulations indicated that the CPL experiment provided more favorable initial and boundary conditions than the CNTL experiment to simulate TC tracks more accurately.

  19. Combining Recurrence Analysis and Automatic Movement Extraction from Video Recordings to Study Behavioral Coupling in Face-to-Face Parent-Child Interactions.

    Science.gov (United States)

    López Pérez, David; Leonardi, Giuseppe; Niedźwiecka, Alicja; Radkowska, Alicja; Rączaszek-Leonardi, Joanna; Tomalski, Przemysław

    2017-01-01

    The analysis of parent-child interactions is crucial for the understanding of early human development. Manual coding of interactions is a time-consuming task, which is a limitation in many projects. This becomes especially demanding if a frame-by-frame categorization of movement needs to be achieved. To overcome this, we present a computational approach for studying movement coupling in natural settings, which is a combination of a state-of-the-art automatic tracker, Tracking-Learning-Detection (TLD), and nonlinear time-series analysis, Cross-Recurrence Quantification Analysis (CRQA). We investigated the use of TLD to extract and automatically classify movement of each partner from 21 video recordings of interactions, where 5.5-month-old infants and mothers engaged in free play in laboratory settings. As a proof of concept, we focused on those face-to-face episodes, where the mother animated an object in front of the infant, in order to measure the coordination between the infants' head movement and the mothers' hand movement. We also tested the feasibility of using such movement data to study behavioral coupling between partners with CRQA. We demonstrate that movement can be extracted automatically from standard definition video recordings and used in subsequent CRQA to quantify the coupling between movement of the parent and the infant. Finally, we assess the quality of this coupling using an extension of CRQA called anisotropic CRQA and show asymmetric dynamics between the movement of the parent and the infant. When combined these methods allow automatic coding and classification of behaviors, which results in a more efficient manner of analyzing movements than manual coding.

  20. Quantum and thermal ionic motion, oxygen isotope effect, and superexchange distribution in La2CuO4

    DEFF Research Database (Denmark)

    Haefliger, P. S.; Gerber, S.; Pramod, R.

    2014-01-01

    We study the zero-point and thermal ionic motion in La2CuO4 by means of high-resolution neutron-diffraction experiments. Our results demonstrate anisotropic motion of O and, to a lesser extent, Cu ions, both consistent with the structure of coupled CuO6 octahedra, and quantify the relative effect...... in J values that are subject to significant (8-12%) isotope effects. We demonstrate that this motional broadening of J can have substantial effects on certain electronic and magnetic properties in cuprates.......We study the zero-point and thermal ionic motion in La2CuO4 by means of high-resolution neutron-diffraction experiments. Our results demonstrate anisotropic motion of O and, to a lesser extent, Cu ions, both consistent with the structure of coupled CuO6 octahedra, and quantify the relative effects...

  1. Spin quantum tunneling via entangled states in a dimer of exchange coupled single-molecule magnets

    Science.gov (United States)

    Tiron, R.; Wernsdorfer, W.; Aliaga-Alcalde, N.; Foguet-Albiol, D.; Christou, G.

    2004-03-01

    A new family of supramolecular, antiferromagnetically exchange-coupled dimers of single-molecule magnets (SMMs) has recently been reported [W. Wernsdorfer, N. Aliaga-Alcalde, D.N. Hendrickson, and G. Christou, Nature 416, 406 (2002)]. Each SMM acts as a bias on its neighbor, shifting the quantum tunneling resonances of the individual SMMs. Hysteresis loop measurements on a single crystal of SMM-dimers have now established quantum tunneling of the magnetization via entangled states of the dimer. This shows that the dimer really does behave as a quantum-mechanically coupled dimer. The transitions are well separated, suggesting long coherence times compared to the time scale of the energy splitting. This result is of great importance if such systems are to be used for quantum computing. It also allows the measurement of the longitudinal and transverse superexchange coupling constants [Phys. Rev. Lett. 91, 227203 (2003)].

  2. Phosphatidic acid regulates signal output by G protein coupled receptors through direct interaction with phospholipase C-beta(1).

    Science.gov (United States)

    Litosch, Irene; Pujari, Rajeshree; Lee, Shawn J

    2009-09-01

    Phosphatidic acid (PA), generated downstream of monomeric Rho GTPases via phospholipase D (PLD) and additionally by diacylglycerol kinases (DGK), both stimulates phospholipase C-beta(1) (PLC-beta(1)) and potentiates stimulation of PLC-beta(1) activity by Galpha(q) in vitro. PA is a potential candidate for integrating signaling by monomeric and heterotrimeric G proteins to regulate signal output by G protein coupled receptors (GPCR), and we have sought to understand the mechanisms involved. We previously identified the region spanning residues 944-957, lying within the PLC-beta(1) C-terminus alphaA helix and flexible loop of the Galpha(q) binding domain, as required for stimulation of lipase activity by PA in vitro. Regulation by PA does not require residues essential for stimulation by Galpha(q) or GTPase activating activity. The present studies evaluated shorter alanine/glycine replacement mutants and finally point mutations to identify Tyr(952) and Ile(955) as key determinants for regulation by PA, assessed by both in vitro enzymatic and cell-based co-transfection assays. Replacement of Tyr(952) and Ile(955), PLC-beta(1) (Y952G/I955G), results in an 85% loss in stimulation by PA relative to WT-PLC-beta(1) in vitro. COS 7 cells co-transfected with PLC-beta(1) (Y952G/I955G) demonstrate a 10-fold increase in the EC(50) for stimulation and a 60% decrease in maximum stimulation by carbachol via Galpha(q) linked m1 muscarinic receptors, relative to cells co-transfected with WT-PLC-beta(1) but otherwise similar conditions. Residues required for regulation by PA are not essential for stimulation by G protein subunits. WT-PLC-beta(1) and PLC-beta(1) (Y952G/I955G) activity is increased comparably by co-transfection with Galpha(q) and neither is markedly affected by co-transfection with Gbeta(1)gamma(2). Inhibiting PLD-generated PA production by 1-butanol has little effect on maximum stimulation, but shifts the EC(50) for agonist stimulation of WT-PLC-beta(1) by 10-fold

  3. Influence of magnetoelastic coupling on the phase transitions in two-dimensional non-Heisenberg magnetics with biquadratic interaction

    International Nuclear Information System (INIS)

    Fridman, Yu.A.; Klevets, Ph.N.; Kozhemyako, O.V.

    2003-01-01

    Influence of magnetoelastic (ME) interaction on the phase transitions in two-dimensional non-Heisenberg ferromagnets is investigated. It is shown that if the constant of Heisenberg exchange interaction is large, the ferromagnetic phase is implemented in a system. When the value of biquadratic exchange interaction increases there is a phase transition to the quadrupolar phase characterized by the tensor order parameters. Thus, ME interaction plays an essential role, not only stabilizing the long-range magnetic order in the system, but also determining the order of the phase transition

  4. Coupling a three-dimensional subsurface flow and transport model with a land surface model to simulate stream–aquifer–land interactions (CP v1.0

    Directory of Open Access Journals (Sweden)

    G. Bisht

    2017-12-01

    Full Text Available A fully coupled three-dimensional surface and subsurface land model is developed and applied to a site along the Columbia River to simulate three-way interactions among river water, groundwater, and land surface processes. The model features the coupling of the Community Land Model version 4.5 (CLM4.5 and a massively parallel multiphysics reactive transport model (PFLOTRAN. The coupled model, named CP v1.0, is applied to a 400 m × 400 m study domain instrumented with groundwater monitoring wells along the Columbia River shoreline. CP v1.0 simulations are performed at three spatial resolutions (i.e., 2, 10, and 20 m over a 5-year period to evaluate the impact of hydroclimatic conditions and spatial resolution on simulated variables. Results show that the coupled model is capable of simulating groundwater–river-water interactions driven by river stage variability along managed river reaches, which are of global significance as a result of over 30 000 dams constructed worldwide during the past half-century. Our numerical experiments suggest that the land-surface energy partitioning is strongly modulated by groundwater–river-water interactions through expanding the periodically inundated fraction of the riparian zone, and enhancing moisture availability in the vadose zone via capillary rise in response to the river stage change. Meanwhile, CLM4.5 fails to capture the key hydrologic process (i.e., groundwater–river-water exchange at the site, and consequently simulates drastically different water and energy budgets. Furthermore, spatial resolution is found to significantly impact the accuracy of estimated the mass exchange rates at the boundaries of the aquifer, and it becomes critical when surface and subsurface become more tightly coupled with groundwater table within 6 to 7 meters below the surface. Inclusion of lateral subsurface flow influenced both the surface energy budget and subsurface transport processes as a result

  5. Coupling a three-dimensional subsurface flow and transport model with a land surface model to simulate stream-aquifer-land interactions (CP v1.0)

    Science.gov (United States)

    Bisht, Gautam; Huang, Maoyi; Zhou, Tian; Chen, Xingyuan; Dai, Heng; Hammond, Glenn E.; Riley, William J.; Downs, Janelle L.; Liu, Ying; Zachara, John M.

    2017-12-01

    A fully coupled three-dimensional surface and subsurface land model is developed and applied to a site along the Columbia River to simulate three-way interactions among river water, groundwater, and land surface processes. The model features the coupling of the Community Land Model version 4.5 (CLM4.5) and a massively parallel multiphysics reactive transport model (PFLOTRAN). The coupled model, named CP v1.0, is applied to a 400 m × 400 m study domain instrumented with groundwater monitoring wells along the Columbia River shoreline. CP v1.0 simulations are performed at three spatial resolutions (i.e., 2, 10, and 20 m) over a 5-year period to evaluate the impact of hydroclimatic conditions and spatial resolution on simulated variables. Results show that the coupled model is capable of simulating groundwater-river-water interactions driven by river stage variability along managed river reaches, which are of global significance as a result of over 30 000 dams constructed worldwide during the past half-century. Our numerical experiments suggest that the land-surface energy partitioning is strongly modulated by groundwater-river-water interactions through expanding the periodically inundated fraction of the riparian zone, and enhancing moisture availability in the vadose zone via capillary rise in response to the river stage change. Meanwhile, CLM4.5 fails to capture the key hydrologic process (i.e., groundwater-river-water exchange) at the site, and consequently simulates drastically different water and energy budgets. Furthermore, spatial resolution is found to significantly impact the accuracy of estimated the mass exchange rates at the boundaries of the aquifer, and it becomes critical when surface and subsurface become more tightly coupled with groundwater table within 6 to 7 meters below the surface. Inclusion of lateral subsurface flow influenced both the surface energy budget and subsurface transport processes as a result of river-water intrusion into the

  6. A Comprehensive Analysis of Jet Quenching via a Hybrid Strong/Weak Coupling Model for Jet-Medium Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Casalderrey-Solana, Jorge [Departament d' Estructura i Constituents de la Matèria and Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Gulhan, Doga Can [Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Milhano, José Guilherme [CENTRA, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, P-1049-001 Lisboa (Portugal); Physics Department, Theory Unit, CERN, CH-1211 Genève 23 (Switzerland); Pablos, Daniel [Departament d' Estructura i Constituents de la Matèria and Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); Rajagopal, Krishna [Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2016-12-15

    Within a hybrid strong/weak coupling model for jets in strongly coupled plasma, we explore jet modifications in ultra-relativistic heavy ion collisions. Our approach merges the perturbative dynamics of hard jet evolution with the strongly coupled dynamics which dominates the soft exchanges between the fast partons in the jet shower and the strongly coupled plasma itself. We implement this approach in a Monte Carlo, which supplements the DGLAP shower with the energy loss dynamics as dictated by holographic computations, up to a single free parameter that we fit to data. We then augment the model by incorporating the transverse momentum picked up by each parton in the shower as it propagates through the medium, at the expense of adding a second free parameter. We use this model to discuss the influence of the transverse broadening of the partons in a jet on intra-jet observables. In addition, we explore the sensitivity of such observables to the back-reaction of the plasma to the passage of the jet.

  7. Spontaneous emission spectra and quantum light-matter interactions from a strongly coupled quantum dot metal-nanoparticle system

    DEFF Research Database (Denmark)

    Van Vlack, C.; Kristensen, Philip Trøst; Hughes, S.

    2012-01-01

    the dot to the detector, we demonstrate that the strong-coupling regime should be observable in the far-field spontaneous emission spectrum, even at room temperature. The vacuum-induced emission spectra show that the usual vacuum Rabi doublet becomes a rich spectral triplet or quartet with two of the four...

  8. A rigorous nonorthogonal configuration interaction approach for the calculation of electronic couplings between diabatic states applied to singlet fission

    NARCIS (Netherlands)

    Wibowo, Meilani; Broer, Ria; Havenith, Remco W. A.

    2017-01-01

    For the design of efficient singlet fission chromophores, knowledge of the factors that govern the singlet fission rate is important. This rate is approximately proportional to the electronic coupling between the lowest (diabatic) spin singlet state that is populated following photoexcitation state

  9. Investigation of land ice-ocean interaction with a fully coupled ice-ocean model: 2. Sensitivity to external forcings

    Science.gov (United States)

    Goldberg, D. N.; Little, C. M.; Sergienko, O. V.; Gnanadesikan, A.; Hallberg, R.; Oppenheimer, M.

    2012-06-01

    A coupled ice stream-ice shelf-ocean cavity model is used to assess the sensitivity of the coupled system to far-field ocean temperatures, varying from 0.0 to 1.8°C, as well as sensitivity to the parameters controlling grounded ice flow. A response to warming is seen in grounding line retreat and grounded ice loss that cannot be inferred from the response of integrated melt rates alone. This is due to concentrated thinning at the ice shelf lateral margin, and to processes that contribute to this thinning. Parameters controlling the flow of grounded ice have a strong influence on the response to sub-ice shelf melting, but this influence is not seen until several years after an initial perturbation in temperatures. The simulated melt rates are on the order of that observed for Pine Island Glacier in the 1990s. However, retreat rates are much slower, possibly due to unrepresented bedrock features.

  10. Experimental characterization of a strongly coupled solid density plasma generated in a short-pulse laser target interaction

    International Nuclear Information System (INIS)

    Gregori, G.; Hansen, S.B.; Key, M.H.; King, J.; Mackinnon, A.J.; Park, H.; Patel, P.K.; Shepard, R.; Snavely, R.A.; Wilks, S.C.; Glenzer, S.H.

    2005-01-01

    We have measured high resolution copper Kα spectra from a picosecond high intensity laser produced plasma. By fitting the shape of the experimental spectra with a self-consistent-field model which includes all the relevant line shifts from multiply ionized atoms, we are able to infer time and spatially averaged electron temperatures (T e ) and ionization state (Z) in the foil. Our results show increasing values for T e and Z when the overall mass of the target is reduced. In particular, we measure temperatures in excess of 200 eV with Z ∼ 13-14. For these conditions the ion-ion coupling constant is Λ ii ∼ 8-9, thus suggesting the achievement of a strongly coupled plasma regime

  11. Experimental characterization of a strongly coupled solid density plasma generated in a short-pulse laser target interaction

    Energy Technology Data Exchange (ETDEWEB)

    Gregori, G; Hansen, S B; Key, M H; King, J; Mackinnon, A J; Park, H; Patel, P K; Shepard, R; Snavely, R A; Wilks, S C; Glenzer, S H

    2005-03-17

    We have measured high resolution copper K{alpha} spectra from a picosecond high intensity laser produced plasma. By fitting the shape of the experimental spectra with a self-consistent-field model which includes all the relevant line shifts from multiply ionized atoms, we are able to infer time and spatially averaged electron temperatures (T{sub e}) and ionization state (Z) in the foil. Our results show increasing values for T{sub e} and Z when the overall mass of the target is reduced. In particular, we measure temperatures in excess of 200 eV with Z {approx} 13-14. For these conditions the ion-ion coupling constant is {Lambda}{sub ii} {approx} 8-9, thus suggesting the achievement of a strongly coupled plasma regime.

  12. The influence of further-neighbor spin-spin interaction on a ground state of 2D coupled spin-electron model in a magnetic field

    Science.gov (United States)

    Čenčariková, Hana; Strečka, Jozef; Gendiar, Andrej; Tomašovičová, Natália

    2018-05-01

    An exhaustive ground-state analysis of extended two-dimensional (2D) correlated spin-electron model consisting of the Ising spins localized on nodal lattice sites and mobile electrons delocalized over pairs of decorating sites is performed within the framework of rigorous analytical calculations. The investigated model, defined on an arbitrary 2D doubly decorated lattice, takes into account the kinetic energy of mobile electrons, the nearest-neighbor Ising coupling between the localized spins and mobile electrons, the further-neighbor Ising coupling between the localized spins and the Zeeman energy. The ground-state phase diagrams are examined for a wide range of model parameters for both ferromagnetic as well as antiferromagnetic interaction between the nodal Ising spins and non-zero value of external magnetic field. It is found that non-zero values of further-neighbor interaction leads to a formation of new quantum states as a consequence of competition between all considered interaction terms. Moreover, the new quantum states are accompanied with different magnetic features and thus, several kinds of field-driven phase transitions are observed.

  13. Experimental studies and modelling of cation interactions with solid materials: application to the MIMICC project. (Multidimensional Instrumented Module for Investigations on chemistry-transport Coupled Codes)

    International Nuclear Information System (INIS)

    Hardin, Emmanuelle

    1999-01-01

    The study of cation interactions with solid materials is useful in order to define the chemistry interaction component of the MIMICC project (Multidimensional Instrumented Module for Investigations on chemistry-transport Coupled Codes). This project will validate the chemistry-transport coupled codes. Database have to be supplied on the cesium or ytterbium interactions with solid materials in suspension. The solid materials are: a strong cation exchange resin, a natural sand which presents small impurities, and a zirconium phosphate. The cation exchange resin is useful to check that the surface complexation theory can be applied on a pure cation exchanger. The sand is a natural material, and its isotherms will be interpreted using pure oxide-cation system data, such as pure silica-cation data. Then the study on the zirconium phosphate salt is interesting because of the increasing complexity in the processes (dissolution, sorption and co-precipitation). These data will enable to approach natural systems, constituted by several complex solids which can interfere on each other. These data can also be used for chemistry-transport coupled codes. Potentiometric titration, sorption isotherms, sorption kinetics, cation surface saturation curves are made, in order to obtain the different parameters relevant to the cation sorption at the solid surface, for each solid-electrolyte-cation system. The influence of different parameters such as ionic strength, pH, and electrolyte is estimated. All the experimental curves are fitted with FITEQL code based on the surface complexation theory using the constant capacitance model, in order to give a mechanistic interpretation of the ion retention phenomenon at the solid surface. The speciation curves of all systems are plotted, using the FITEQL code too. Systems with an increasing complexity are studied: dissolution, sorption and coprecipitation coexist in the cation-salt systems. Then the data obtained on each single solid, considered

  14. The Interaction of a N-Type Four Level Atom with the Electromagnetic Field for a Kerr Medium Induced Intensity-Dependent Coupling

    Science.gov (United States)

    Othman, Anas; Yevick, David

    2018-01-01

    The interaction of a N-type four-level atom with a single field in the presence of an intensity-dependent coupling in a nonlinear Kerr medium is investigated. The exact analytic solution is obtained in the case that the atom and electromagnetic field are initially in a higher excited state and a coherent state, respectively. It is then demonstrated that effects such as nonclassical light generation, degree of entanglement stabilization, Kerr medium nonclassical control, and squeezed light are can be more efficiently implemented within this four-level framework than in many competing procedures. Additionally, inversion, linear entropy, Mandel Q-parameter and normal squeezing dynamics are examined.

  15. Sign of the electron exchange coupling in random radical encounter pairs in solution

    International Nuclear Information System (INIS)

    Thurnauer, M.C.; Chiu, T.M.; Trifunac, A.D.

    1985-01-01

    An important parameter in the study of reacting radical systems is the electron exchange interaction, J. The properties of interest are the sign and magnitude of J, and its functional dependence on distance between radicals. One source of information about J is from understanding the Chemically Induced Dynamic Electron Polarization (CIDEP) which is observed in the EPR spectra of reactive radical systems. For radicals reacting in solution to form new covalent bonds, it has generally been found that J O. It is suggested that F-pairs react at a separation greater than that at which spin correlated (geminate) pairs of the same radicals are formed, so that the intervening solvent molecules become involved in the exchange interaction giving rise to J>O via some sort of superexchange process. This is an interesting proposition since superexchange via solvent molecules may play a role in rates of long-distance electron transfer reactions and in the electron transfer reactions of photosynthesis. However, the model suggested runs contrary to all F-air radicals are produced. In order to clarify this important point, the authors present here a definitive study in which we examine several systems of radgenerated independently (exclusive F-pairs) by pulsed laser photolysis and pulsed radiolicals generatedysis in aqueous, alcoholic and hydrocarbon solvents

  16. Interaction between Polyketide Synthase and Transporter Suggests Coupled Synthesis and Export of Virulence Lipid in M. tuberculosis.

    Directory of Open Access Journals (Sweden)

    2005-09-01

    Full Text Available Virulent mycobacteria utilize surface-exposed polyketides to interact with host cells, but the mechanism by which these hydrophobic molecules are transported across the cell envelope to the surface of the bacteria is poorly understood. Phthiocerol dimycocerosate (PDIM, a surface-exposed polyketide lipid necessary for Mycobacterium tuberculosis virulence, is the product of several polyketide synthases including PpsE. Transport of PDIM requires MmpL7, a member of the MmpL family of RND permeases. Here we show that a domain of MmpL7 biochemically interacts with PpsE, the first report of an interaction between a biosynthetic enzyme and its cognate transporter. Overexpression of the interaction domain of MmpL7 acts as a dominant negative to PDIM synthesis by poisoning the interaction between synthase and transporter. This suggests that MmpL7 acts in complex with the synthesis machinery to efficiently transport PDIM across the cell membrane. Coordination of synthesis and transport may not only be a feature of MmpL-mediated transport in M. tuberculosis, but may also represent a general mechanism of polyketide export in many different microorganisms.

  17. Illustration of the Alliances platform chemistry/transport coupling capacities through the simulation of a cement/clay interaction

    International Nuclear Information System (INIS)

    Dimier, A.; Michau, N.; Montarnal, Ph.; Corrihons, F.

    2003-01-01

    Safety studies in a subsurface environment and in an underground waste disposal necessitate numerical tools for reactive transport modelling. In these systems, hydrogeological and chemical processes are closely related and their interdependence must be analysed to study migration of species. We will illustrate here the capacities of the Alliances tool to simulate such a phenomenology by studying the evolution of a clay/cement interface over time. The goal being defined, the two main employed software to build up a multidimensional tool have been chosen, namely PhreeqC and Chess for chemistry. A common model has been developed whose aim is to allow models comparison while switching between the chemistry tools. For transport, Castem and Mt3d-99 have been introduced with the same philosophy of structure. It is worth noting that other tools could be introduced, the only requirement being to satisfy the specific data-model and building up the appropriate methods. Qualification cases have been built up to define the platform application field. It has been defined with one and two dimensional cases enabling a comparison with analytic solutions or an intercomparison with other reactive transport codes. To illustrate this in the chemistry coupling field, we focus on a clay cement interface with an ion exchange linked to the Ca-montmorillonite. This case has been defined at ANDRA to be used as a reference test case for chemistry coupling validation. Results show a good agreement between platform results and whose of PhreeqC with its own internal coupling. The clay/cement interface is reproduced with the same accuracy

  18. Dark coupling

    International Nuclear Information System (INIS)

    Gavela, M.B.; Hernández, D.; Honorez, L. Lopez; Mena, O.; Rigolin, S.

    2009-01-01

    The two dark sectors of the universe—dark matter and dark energy—may interact with each other. Background and linear density perturbation evolution equations are developed for a generic coupling. We then establish the general conditions necessary to obtain models free from non-adiabatic instabilities. As an application, we consider a viable universe in which the interaction strength is proportional to the dark energy density. The scenario does not exhibit ''phantom crossing'' and is free from instabilities, including early ones. A sizeable interaction strength is compatible with combined WMAP, HST, SN, LSS and H(z) data. Neutrino mass and/or cosmic curvature are allowed to be larger than in non-interacting models. Our analysis sheds light as well on unstable scenarios previously proposed

  19. Strong-coupling superconductivity in the two-dimensional t-J model supplemented by a hole-phonon interaction

    International Nuclear Information System (INIS)

    Sherman, A.; Schreiber, M.

    1995-01-01

    We use the Eliashberg formalism for calculating T c in a model of cuprate perovskites with pairing mediated by both magnons and apex-oxygen vibrations. The influence of strong correlations on the energy spectrum is taken into account in the spin-wave approximation. It is shown that the hole-magnon interaction alone cannot yield high T c . But together with a moderate hole-phonon interaction it does lead to d-wave superconductivity at temperatures and hole concentrations observed in cuprates. High T c are connected with a large density of states due to extended Van Hove singularities, a conformity of the two interactions for the d symmetry, and high phonon frequencies

  20. Mechanism of conformational coupling in SecA: Key role of hydrogen-bonding networks and water interactions.

    Science.gov (United States)

    Milenkovic, Stefan; Bondar, Ana-Nicoleta

    2016-02-01

    SecA uses the energy yielded by the binding and hydrolysis of adenosine triphosphate (ATP) to push secretory pre-proteins across the plasma membrane in bacteria. Hydrolysis of ATP occurs at the nucleotide-binding site, which contains the conserved carboxylate groups of the DEAD-box helicases. Although crystal structures provide valuable snapshots of SecA along its reaction cycle, the mechanism that ensures conformational coupling between the nucleotide-binding site and the other domains of SecA remains unclear. The observation that SecA contains numerous hydrogen-bonding groups raises important questions about the role of hydrogen-bonding networks and hydrogen-bond dynamics in long-distance conformational couplings. To address these questions, we explored the molecular dynamics of SecA from three different organisms, with and without bound nucleotide, in water. By computing two-dimensional hydrogen-bonding maps we identify networks of hydrogen bonds that connect the nucleotide-binding site to remote regions of the protein, and sites in the protein that respond to specific perturbations. We find that the nucleotide-binding site of ADP-bound SecA has a preferred geometry whereby the first two carboxylates of the DEAD motif bridge via hydrogen-bonding water. Simulations of a mutant with perturbed ATP hydrolysis highlight the water-bridged geometry as a key structural element of the reaction path. Copyright © 2015. Published by Elsevier B.V.

  1. Fluxes of lactate into, from, and among gap junction-coupled astrocytes and their interaction with noradrenaline

    Directory of Open Access Journals (Sweden)

    Leif eHertz

    2014-09-01

    Full Text Available Lactate is a versatile metabolite with important roles in modulation of brain glucose utilization rate (CMRglc, diagnosis of brain-injured patients, redox- and receptor-mediated signaling, memory, and alteration of gene transcription. Neurons and astrocytes release and accumulate lactate using equilibrative monocarboxylate transporters that carry out net transmembrane transport of lactate only until intra- and extracellular levels reach equilibrium. Astrocytes have much faster lactate uptake than neurons and shuttle more lactate among gap junction-coupled astrocytes than to nearby neurons. Lactate diffusion within syncytia can provide precursors for oxidative metabolism and glutamate synthesis and facilitate its release from endfeet to perivascular space to stimulate blood flow. Lactate efflux from brain during activation underlies the large underestimation of CMRglc with labeled glucose and fall in CMRO2/CMRglc ratio. Receptor-mediated effects of lactate on locus coeruleus neurons include noradrenaline release in cerebral cortex and c-AMP-mediated stimulation of astrocytic gap junctional coupling, thereby enhancing its dispersal and release from brain. Lactate transport is essential for its multifunctional roles.

  2. Genealogical electronic coupling procedure incorporating the Hartree--Fock interacting space and suitable for degenerate point groups. Application to excited states of BH3

    International Nuclear Information System (INIS)

    Swope, W.C.; Schaefer, H.F. III; Yarkony, D.R.

    1980-01-01

    The use of Clebsch--Gordan-type coupling coefficients for finite point groups is applied to the problem of constructing symmetrized N-electron wave functions (configurations) for use by the Hartree--Fock SCF and CI methods of determining electronic wave functions for molecular systems. The configurations are eigenfunctions of electronic spin operators, and transform according to a particular irreducible representation of the relevant group of spatial operations which leave the Born--Oppenheimer Hamiltonian invariant. The method proposed for constructing the configurations involves a genealogical coupling procedure. It is particularly useful for studies of molecules which belong to a group which has multiply degenerate irreducible representations. The advantage of the method is that it results in configurations which are real linear combinations of determinants of real symmetry orbitals. This procedure for constructing configurations also allows for the identification of configurations which have no matrix element of the Hamiltonian with a reference configuration. It is therefore possible to construct a Hartree--Fock interacting space of configurations which can speed the convergence of a CI wave function. The coupling method is applied to a study of the ground and two excited electronic states of BH 3 in its D/sub 3h/ geometry. The theoretical approach involved Hartree--Fock SCF calculations followed by single and double substitution CI calculations, both of which employed double-zeta plus polarization quality basis sets

  3. Axisymmetric alternating direction explicit scheme for efficient coupled simulation of hydro-mechanical interaction in geotechnical engineering—Application to circular footing and deep tunnel in saturated ground

    Directory of Open Access Journals (Sweden)

    Simon Heru Prassetyo

    2018-04-01

    Full Text Available Explicit solution techniques have been widely used in geotechnical engineering for simulating the coupled hydro-mechanical (H-M interaction of fluid flow and deformation induced by structures built above and under saturated ground, i.e. circular footing and deep tunnel. However, the technique is only conditionally stable and requires small time steps, portending its inefficiency for simulating large-scale H-M problems. To improve its efficiency, the unconditionally stable alternating direction explicit (ADE scheme could be used to solve the flow problem. The standard ADE scheme, however, is only moderately accurate and is restricted to uniform grids and plane strain flow conditions. This paper aims to remove these drawbacks by developing a novel high-order ADE scheme capable of solving flow problems in non-uniform grids and under axisymmetric conditions. The new scheme is derived by performing a fourth-order finite difference (FD approximation to the spatial derivatives of the axisymmetric fluid–diffusion equation in a non-uniform grid configuration. The implicit Crank-Nicolson technique is then applied to the resulting approximation, and the subsequent equation is split into two alternating direction sweeps, giving rise to a new axisymmetric ADE scheme. The pore pressure solutions from the new scheme are then sequentially coupled with an existing geomechanical simulator in the computer code fast Lagrangian analysis of continua (FLAC. This coupling procedure is called the sequentially-explicit coupling technique based on the fourth-order axisymmetric ADE scheme or SEA-4-AXI. Application of SEA-4-AXI for solving axisymmetric consolidation of a circular footing and of advancing tunnel in deep saturated ground shows that SEA-4-AXI reduces computer runtime up to 42%–50% that of FLAC's basic scheme without numerical instability. In addition, it produces high numerical accuracy of the H-M solutions with average percentage difference of only 0.5%

  4. Improving the performance of finite element simulations on the wheel–rail interaction by using a coupling strategy

    NARCIS (Netherlands)

    Ma, Y.; Markine, V.L.; Ahad Mashal, Abdul; Ren, Mingfa

    2018-01-01

    Over the past few years, a number of implicit/explicit finite element models have been introduced for the purpose of tackling the problems of wheel–rail interaction. Yet, most of those finite element models encounter common numerical difficulties. For instance, initial gaps/penetrations between two

  5. Factors controlling the mode of rift interaction in brittle-ductile coupled systems: A 3D numerical study

    NARCIS (Netherlands)

    Allken, V.; Huismans, R.S.; Thieulot, C.

    2012-01-01

    The way individual faults and rift segments link up is a fundamental aspect of lithosphere extension and continental break-up. Little is known however about the factors that control the selection of the different modes of rift interaction observed in nature. Here we use state-of-the-art large

  6. Vibration of a Coupled Plate/Fluid Interacting System and its implication for Modal Analysis and Vibration Health Monitoring

    Czech Academy of Sciences Publication Activity Database

    Gorman, D. G.; Trendafilova, I.; Mulholland, F.; Horáček, Jaromír

    5-6, - (2006), s. 323-330 ISSN 1660-9336 R&D Projects: GA AV ČR(CZ) IAA2076101 Institutional research plan: CEZ:AV0Z20760514 Keywords : vibrations * vibro-acoustic interaction * structural/acoustic Subject RIV: BI - Acoustics

  7. Design of a master Fastbus for the data acquisition of the DELPHI external detector. Measurement of the strong interaction coupling constant in the Z neutral boson hadronic decay

    International Nuclear Information System (INIS)

    Chorowicz, V.

    1990-05-01

    The thesis was prepared at the Delphi experiment. The work, performed in the LPNHE-Paris group, consists of two steps: the data acquisition at the Delphi External Detector and the analysis of the hadronic data, in order to extract the coupling constant of the strong interactions at √s = 91 GeV. In the first part of the thesis, the constraints relating to the data acquisition and the Delphi output are discussed. The data acquisition system of the External Detector and the implementation of the AM29000 on the main Fastbus are described. The AM29000 is a RISC type processor, which can support the high frequencies expected from the beam luminosity increase at LEP. This module will replace front end freeing monitor which is presently controlled by a 68020 microprocessor. In the second part of the thesis, the data acquired at Delphi from September to December 1989 is analyzed. The investigation is focused on the hadronic events in order to obtain the Standard Model basic parameter: the Λ QCD , which determines the energy dependence of the strong interactions coupling constant. A method based on the measurement of the energy-energy correlations in the hadronic jets is used and the results are discussed. The Λ QCD value is obtained by fitting the theoretical expected value to the distribution of the energy-energy correlations asymmetry [fr

  8. Modeling interactions of agriculture and groundwater nitrate contaminants: application of The STICS-Eau-Dyssée coupled models over the Seine River Basin

    Science.gov (United States)

    Tavakoly, A. A.; Habets, F.; Saleh, F.; Yang, Z. L.

    2017-12-01

    Human activities such as the cultivation of N-fixing crops, burning of fossil fuels, discharging of industrial and domestic effluents, and extensive usage of fertilizers have recently accelerated the nitrogen loading to watersheds worldwide. Increasing nitrate concentration in surface water and groundwater is a major concern in watersheds with extensive agricultural activities. Nutrient enrichment is one of the major environmental problems in the French coastal zone. To understand and predict interactions between agriculture, surface water and groundwater nitrate contaminants, this study presents a modeling framework that couples the agronomic STICS model with Eau-Dyssée, a distributed hydrologic modeling system to simulate groundwater-surface water interaction. The coupled system is implemented on the Seine River Basin with an area of 88,000 km2 to compute daily nitrate contaminants. Representing a sophisticated hydrosystem with several aquifers and including the megalopolis of Paris, the Seine River Basin is well-known as one of the most productive agricultural areas in France. The STICS-EauDyssée framework is evaluated for a long-term simulation covering 39 years (1971-2010). Model results show that the simulated nitrate highly depends on the inflow produced by surface and subsurface waters. Daily simulation shows that the model captures the seasonal variation of observations and that the overall long-term simulation of nitrate contaminant is satisfactory at the regional scale.

  9. The influence of starch oxidization and aluminate coupling agent on interfacial interaction, rheological behavior, mechanical and thermal properties of poly(propylene carbonate)/starch blends

    Science.gov (United States)

    Jiang, Guo; Zhang, Shui-Dong; Huang, Han-Xiong; The Key Laboratory of Polymer Processing Engineering of the Ministry of Education Team

    Poly(propylene carbonate) (PPC) is a kind of new biodegradable polymer that is synthesized by copolymerization of propylene oxide and carbon dioxide. In this work, PPC end-capped with maleic anhydride (PPCMA)/thermoplastic starch (TPS), PPCMA/thermoplastic oxidized starch (TPOS) and PPCMA/AL-TPOS (TPOS modified by aluminate coupling agent) blends were prepared by melt blending to improve its thermal and mechanical properties. FTIR results showed that there existed hydrogen-bonding interaction between PPCMA and starch. SEM observation revealed that the compatibility between PPCMA and TPOS was improved by the oxidation of starch. The enhanced interfacial interactions between PPCMA and TPOS led to a better performance of PPC blends such as storage modulus (G'), loss modulus (G''), complex viscosity (η*), tensile strength and thermal properties. Furthermore, the modification of TPOS by aluminate coupling agent (AL) facilitated the dispersion of oxidized starch in PPC matrix, and resulted in increasing the tensile strength and thermal stability. National Natural Science Foundation of China, National Science Fund of Guangdong Province.

  10. Entanglement and Other Nonclassical Properties of Two Two-Level Atoms Interacting with a Two-Mode Binomial Field: Constant and Intensity-Dependent Coupling Regimes

    International Nuclear Information System (INIS)

    Tavassoly, M.K.; Hekmatara, H.

    2015-01-01

    In this paper, we consider the interaction between two two-level atoms and a two-mode binomial field with a general intensity-dependent coupling regime. The outlined dynamical problem has explicit analytical solution, by which we can evaluate a few of its physical features of interest. To achieve the purpose of the paper, after choosing a particular nonlinearity function, we investigate the quantum statistics, atomic population inversion and at last the linear entropy of the atom-field system which is a good measure for the degree of entanglement. In detail, the effects of binomial field parameters, in addition to different initial atomic states on the temporal behavior of the mentioned quantities have been analyzed. The results show that, the values of binomial field parameters and the initial state of the two atoms influence on the nonclassical effects in the obtained states through which one can tune the nonclassicality criteria appropriately. Setting intensity-dependent coupling function equal to 1 reduces the results to the constant coupling case. By comparing the latter case with the nonlinear regime, we will observe that the nonlinearity disappears the pattern of collapse-revival phenomenon in the evolution of Mandel parameter and population inversion (which can be seen in the linear case with constant coupling), however, more typical collapse-revivals will be appeared for the cross-correlation function in the nonlinear case. Finally, in both linear and nonlinear regime, the entropy remains less than (but close to) 0.5. In other words the particular chosen nonlinearity does not critically affect on the entropy of the system. (paper)

  11. Modelling of plasma-antenna coupling and non-linear radio frequency wave-plasma-wall interactions in the magnetized plasma device under ion cyclotron range of frequencies

    International Nuclear Information System (INIS)

    Lu, LingFeng

    2016-01-01

    Ion Cyclotron Resonant Heating (ICRH) by waves in 30-80 MHz range is currently used in magnetic fusion plasmas. Excited by phased arrays of current straps at the plasma periphery, these waves exist under two polarizations. The Fast Wave tunnels through the tenuous plasma edge and propagates to its center where it is absorbed. The parasitically emitted Slow Wave only exists close to the launchers. How much power can be coupled to the center with 1 A current on the straps? How do the emitted radiofrequency (RF) near and far fields interact parasitically with the edge plasma via RF sheath rectification at plasma-wall interfaces? To address these two issues simultaneously, in realistic geometry over the size of ICRH antennas, this thesis upgraded and tested the Self-consistent Sheaths and Waves for ICH (SSWICH) code. SSWICH couples self-consistently RF wave propagation and Direct Current (DC) plasma biasing via non-linear RF and DC sheath boundary conditions (SBCs) at plasma/wall interfaces. Its upgrade is full wave and was implemented in two dimensions (toroidal/radial). New SBCs coupling the two polarizations were derived and implemented along shaped walls tilted with respect to the confinement magnetic field. Using this new tool in the absence of SBCs, we studied the impact of a density decaying continuously inside the antenna box and across the Lower Hybrid (LH) resonance. Up to the memory limits of our workstation, the RF fields below the LH resonance changed with the grid size. However the coupled power spectrum hardly evolved and was only weakly affected by the density inside the box. In presence of SBCs, SSWICH-FW simulations have identified the role of the fast wave on RF sheath excitation and reproduced some key experimental observations. SSWICH-FW was finally adapted to conduct the first electromagnetic and RF-sheath 2D simulations of the cylindrical magnetized plasma device ALINE. (author) [fr

  12. A-TOUGH: A multimedia fluid-flow/energy-transport model for fully- coupled atmospheric-subsurface interactions

    International Nuclear Information System (INIS)

    Montazer, P.; Hammermeister, D.; Ginanni, J.

    1994-01-01

    The long-term effect of changes in atmospheric climatological conditions on subsurface hydrological conditions in the unsaturated zone in and environments is an important factor in defining the performance of a high-level and low-level radioactive waste repositories in geological environment. Computer simulation coupled with paleohydrological studies can be used to understand and quantify the potential impact of future climatological conditions on repository performance. A-TOUGH efficiently simulates (given current state-of-the-art technology) the physical processes involved in the near-surface atmosphere and its effect on subsurface conditions. This efficiency is due to the numerical techniques used in TOUGH and the efficient computational techniques used in V-TOUGH to solve non-linear thermodynamic equations that govern the flux of vapor and energy within subsurface porous and fractured media and between these media and the atmosphere

  13. Topology optimisation of micro fluidic mixers considering fluid-structure interactions with a coupled Lattice Boltzmann algorithm

    Science.gov (United States)

    Munk, David J.; Kipouros, Timoleon; Vio, Gareth A.; Steven, Grant P.; Parks, Geoffrey T.

    2017-11-01

    Recently, the study of micro fluidic devices has gained much interest in various fields from biology to engineering. In the constant development cycle, the need to optimise the topology of the interior of these devices, where there are two or more optimality criteria, is always present. In this work, twin physical situations, whereby optimal fluid mixing in the form of vorticity maximisation is accompanied by the requirement that the casing in which the mixing takes place has the best structural performance in terms of the greatest specific stiffness, are considered. In the steady state of mixing this also means that the stresses in the casing are as uniform as possible, thus giving a desired operating life with minimum weight. The ultimate aim of this research is to couple two key disciplines, fluids and structures, into a topology optimisation framework, which shows fast convergence for multidisciplinary optimisation problems. This is achieved by developing a bi-directional evolutionary structural optimisation algorithm that is directly coupled to the Lattice Boltzmann method, used for simulating the flow in the micro fluidic device, for the objectives of minimum compliance and maximum vorticity. The needs for the exploration of larger design spaces and to produce innovative designs make meta-heuristic algorithms, such as genetic algorithms, particle swarms and Tabu Searches, less efficient for this task. The multidisciplinary topology optimisation framework presented in this article is shown to increase the stiffness of the structure from the datum case and produce physically acceptable designs. Furthermore, the topology optimisation method outperforms a Tabu Search algorithm in designing the baffle to maximise the mixing of the two fluids.

  14. New Perspectives for Hadron Phenomenology:The Effects of Final-State Interactions and Near-Conformal Effective QCD Couplings

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S

    2003-10-24

    The effective QCD charge extracted from {tau} decay is remarkably constant at small momenta, implying the near-conformal behavior of hadronic interactions at small momentum transfer. The correspondence of large-N{sub c} supergravity theory in higher-dimensional anti-de Sitter spaces with gauge theory in physical space-time also has interesting implications for hadron phenomenology in the conformal limit, such as constituent counting rules for hard exclusive processes. The utility of light-front quantization and lightfront Fock wavefunctions for analyzing such phenomena and representing the dynamics of QCD bound states is reviewed. I also discuss the novel effects of initial- and final-state interactions in hard QCD inclusive processes, including Bjorken-scaling single-spin asymmetries and the leading-twist diffractive and shadowing contributions to deep inelastic lepton-proton scattering.

  15. Coupling auto trophic in vitro plant cultivation system to scanning electron microscope to study plant-fungal interactions

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, N. de; Decock, C.; Declereck, S.; Providencia, I. E. de la

    2010-07-01

    The interactions of plants with pathogens and beneficial micro-organisms have been seldom compared on the same host and under strict controlled auto trophic in vitro culture conditions. Here, the life cycle of two plant beneficial (Glomus sp. MUCL 41833 and Trichoderma harzianum) and one plant pathogen (Rhizoctonia solani) fungi were described on potato (Solanum tuberosum) plantlets under auto trophic in vitro culture conditions using video camera imaging and the scanning electron microscope (SEM). (i) The colony developmental pattern of the extraradical mycelium within the substrate, (ii) the reproduction structures and (iii) the three-dimensional spatial arrangements of the fungal hyphae within the potato root cells were successfully visualized, monitored and described. The combination of the autotrophic in vitro culture system and SEM represent a powerful tool for improving our knowledge on the dynamics of plant-fungal interactions. (Author) 41 refs.

  16. Schrodinger Equations with Logarithmic Self-Interactions: From Antilinear PT-Symmetry to the Nonlinear Coupling of Channels

    Czech Academy of Sciences Publication Activity Database

    Znojil, Miloslav; Růžička, František; Zloshchastiev, K. G.

    2017-01-01

    Roč. 9, č. 8 (2017), č. článku 165. ISSN 2073-8994 R&D Projects: GA ČR GA16-22945S Institutional support: RVO:61389005 Keywords : PT symmetry * nonlinear Schrodinger equations * logarithmic nonlinearities Subject RIV: BE - Theoretical Physics OBOR OECD: Atomic, molecular and chemical physics ( physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect) Impact factor: 1.457, year: 2016

  17. Investigations of dynamic interactions coupled by soil between neighbouring nuclear power plants of high mass in case of seismic excitation

    International Nuclear Information System (INIS)

    Matthees, W.; Magiera, G.

    1980-01-01

    A sensitivity study for the interaction effects for adjacent structures of nuclear power plants i.e. for main buildings and auxiliary buildings has been performed due to horizontal seismic excitation. An interaction measuring rule for response spectra has been defined as the ratio of amplitude of response calculated inclusive the auxiliary building to the amplitude calculated without the auxiliary building in respect to the proper eigen-frequencies. The calculations of the three-dimensional effects are approximated with the program FLUSH. The accuracy of the achievable response herewith calculated is proven in comparison with other suitable methods. The interaction measuring rule is determined by a parameter investigation including the mathematical model consisting of the soil, the main building, and the auxiliary building. The following assumptions are asserted: 1. the soil characteristics are temporarily constant. Ignorance of the accuracy of the realistic i.e. stress depending soil values is encountered by variation of the decisive characteristics within their applicable band-width. 2. The fineness of the mathematical-mechanical modelling for the structural systems i.e. the number of the degrees of freedom is limited to a minimum. Attention is hereby paid that the eigen-frequencies of the main building as well as the eigen-frequencies of the layered soil system in the range of 0 to 10 Hz are computed with sufficient accuracy. (orig./HP) [de

  18. A parallel interaction potential approach coupled with the immersed boundary method for fully resolved simulations of deformable interfaces and membranes

    Science.gov (United States)

    Spandan, Vamsi; Meschini, Valentina; Ostilla-Mónico, Rodolfo; Lohse, Detlef; Querzoli, Giorgio; de Tullio, Marco D.; Verzicco, Roberto

    2017-11-01

    In this paper we show and discuss how the deformation dynamics of closed liquid-liquid interfaces (for example drops and bubbles) can be replicated with use of a phenomenological interaction potential model. This new approach to simulate liquid-liquid interfaces is based on the fundamental principle of minimum potential energy where the total potential energy depends on the extent of deformation of a spring network distributed on the surface of the immersed drop or bubble. Simulating liquid-liquid interfaces using this model require computing ad-hoc elastic constants which is done through a reverse-engineered approach. The results from our simulations agree very well with previous studies on the deformation of drops in standard flow configurations such as a deforming drop in a shear flow or cross flow. The interaction potential model is highly versatile, computationally efficient and can be easily incorporated into generic single phase fluid solvers to also simulate complex fluid-structure interaction problems. This is shown by simulating flow in the left ventricle of the heart with mechanical and natural mitral valves where the imposed flow, motion of ventricle and valves dynamically govern the behaviour of each other. Results from these simulations are compared with ad-hoc in-house experimental measurements. Finally, we present a simple and easy to implement parallelisation scheme, as high performance computing is unavoidable when studying large scale problems involving several thousands of simultaneously deforming bodies in highly turbulent flows.

  19. Conversation, coupling and complexity

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Abney, Drew; Bahrami, Bahador

    We investigate the linguistic co-construction of interpersonal synergies. By applying a measure of coupling between complex systems to an experimentally elicited corpus of joint decision dialogues, we show that interlocutors’ linguistic behavior displays increasing signature of multi-scale coupling......, known as complexity matching, over the course of interaction. Furthermore, we show that stronger coupling corresponds with more effective interaction, as measured by collective task performance....

  20. Nogo-A couples with Apg-1 through interaction and co-ordinate expression under hypoxic and oxidative stress.

    Science.gov (United States)

    Kern, Florian; Stanika, Ruslan I; Sarg, Bettina; Offterdinger, Martin; Hess, Daniel; Obermair, Gerald J; Lindner, Herbert; Bandtlow, Christine E; Hengst, Ludger; Schweigreiter, Rüdiger

    2013-10-15

    Nogo-A is the largest isoform of the Nogo/RTN4 (reticulon 4) proteins and has been characterized as a major myelin-associated inhibitor of regenerative nerve growth in the adult CNS (central nervous system). Apart from the myelin sheath, Nogo-A is expressed at high levels in principal neurons of the CNS. The specificity of Nogo-A resides in its central domain, NiG. We identified Apg-1, a member of the stress-induced Hsp110 (heat-shock protein of 110 kDa) family, as a novel interactor of NiG/Nogo-A. The interaction is selective because Apg-1 interacts with Nogo-A/RTN4-A, but not with RTN1-A, the closest paralogue of Nogo-A. Conversely, Nogo-A binds to Apg-1, but not to Apg-2 or Hsp105, two other members of the Hsp110 family. We characterized the Nogo-A-Apg-1 interaction by affinity precipitation, co-immunoprecipitation and proximity ligation assay, using primary hippocampal neurons derived from Nogo-deficient mice. Under conditions of hypoxic and oxidative stress we found that Nogo-A and Apg-1 were tightly co-regulated in hippocampal neurons. Although both proteins were up-regulated under hypoxic conditions, their expression levels were reduced upon the addition of hydrogen peroxide. Taken together, we suggest that Nogo-A is closely involved in the neuronal response to hypoxic and oxidative stress, an observation that may be of relevance not only in stroke-induced ischaemia, but also in neuroblastoma formation.

  1. Dynamics of entanglement of a three-level atom in motion interacting with two coupled modes including parametric down conversion

    Science.gov (United States)

    Faghihi, M. J.; Tavassoly, M. K.; Hatami, M.

    In this paper, a model by which we study the interaction between a motional three-level atom and two-mode field injected simultaneously in a bichromatic cavity is considered; the three-level atom is assumed to be in a Λ-type configuration. As a result, the atom-field and the field-field interaction (parametric down conversion) will be appeared. It is shown that, by applying a canonical transformation, the introduced model can be reduced to a well-known form of the generalized Jaynes-Cummings model. Under particular initial conditions, which may be prepared for the atom and the field, the time evolution of state vector of the entire system is analytically evaluated. Then, the dynamics of atom by considering ‘atomic population inversion’ and two different measures of entanglement, i.e., ‘von Neumann entropy’ and ‘idempotency defect’ is discussed, in detail. It is deduced from the numerical results that, the duration and the maximum amount of the considered physical quantities can be suitably tuned by selecting the proper field-mode structure parameter p and the detuning parameters.

  2. Accurate characterization of weak macromolecular interactions by titration of NMR residual dipolar couplings: application to the CD2AP SH3-C:ubiquitin complex.

    Science.gov (United States)

    Ortega-Roldan, Jose Luis; Jensen, Malene Ringkjøbing; Brutscher, Bernhard; Azuaga, Ana I; Blackledge, Martin; van Nuland, Nico A J

    2009-05-01

    The description of the interactome represents one of key challenges remaining for structural biology. Physiologically important weak interactions, with dissociation constants above 100 muM, are remarkably common, but remain beyond the reach of most of structural biology. NMR spectroscopy, and in particular, residual dipolar couplings (RDCs) provide crucial conformational constraints on intermolecular orientation in molecular complexes, but the combination of free and bound contributions to the measured RDC seriously complicates their exploitation for weakly interacting partners. We develop a robust approach for the determination of weak complexes based on: (i) differential isotopic labeling of the partner proteins facilitating RDC measurement in both partners; (ii) measurement of RDC changes upon titration into different equilibrium mixtures of partially aligned free and complex forms of the proteins; (iii) novel analytical approaches to determine the effective alignment in all equilibrium mixtures; and (iv) extraction of precise RDCs for bound forms of both partner proteins. The approach is demonstrated for the determination of the three-dimensional structure of the weakly interacting CD2AP SH3-C:Ubiquitin complex (K(d) = 132 +/- 13 muM) and is shown, using cross-validation, to be highly precise. We expect this methodology to extend the remarkable and unique ability of NMR to study weak protein-protein complexes.

  3. INTERACT

    DEFF Research Database (Denmark)

    Jochum, Elizabeth; Borggreen, Gunhild; Murphey, TD

    This paper considers the impact of visual art and performance on robotics and human-computer interaction and outlines a research project that combines puppetry and live performance with robotics. Kinesics—communication through movement—is the foundation of many theatre and performance traditions ...

  4. Determination of gamma-aminobutyric acid in food matrices by isotope dilution hydrophilic interaction chromatography coupled to mass spectrometry.

    Science.gov (United States)

    Zazzeroni, Raniero; Homan, Andrew; Thain, Emma

    2009-08-01

    The estimation of the dietary intake of gamma-aminobutyric acid (GABA) is dependent upon the knowledge of its concentration values in food matrices. To this end, an isotope dilution liquid chromatography-mass spectrometry method has been developed employing the hydrophilic interaction chromatography technique for analyte separation. This approach enabled accurate quantification of GABA in apple, potato, soybeans, and orange juice without the need of a pre- or post-column derivatization reaction. A selective and precise analytical measurement has been obtained with a triple quadrupole mass spectrometer operating in multiple reaction monitoring using the method of standard additions and GABA-d(6) as an internal standard. The concentrations of GABA found in the matrices tested are 7 microg/g of apple, 342 microg/g of potatoes, 211 microg/g of soybeans, and 344 microg/mL of orange juice.

  5. Effects of Coulomb repulsion on conductivity of heterojunction carbon nanotube quantum dots with spin-orbital coupling and interacting leads

    Energy Technology Data Exchange (ETDEWEB)

    Ogloblya, O.V., E-mail: olexandr.ogloblya@gmail.com [Taras Shevchenko National University, 64/13 Volodymyrska St., Kyiv 01601 (Ukraine); Kuznietsova, H.M. [Taras Shevchenko National University, 64/13 Volodymyrska St., Kyiv 01601 (Ukraine); Strzhemechny, Y.M. [Dept. of Physics and Astronomy, Texas Christian University, Fort Worth, TX 76129 (United States)

    2017-01-01

    We performed numerical studies for the conductance of a heterojunction carbon nanotube quantum dot (QD) with an extra spin orbital quantum number and a conventional QD in which the electron state is determined only by the spin quantum number. Our computational approach took into account the spin-orbit interaction and the Coulomb repulsion both between electrons on a QD as well as between the QD electron and the contacts. We utilized an approach based on the Keldysh non-equilibrium Green's function formalism as well as the equation of motion technique. We focused on the case of a finite Coulombic on-site repulsion and considered two possible cases of applied voltage: spin bias and conventional bias. For the system of interest we obtained bias spectroscopy diagrams, i.e. contour charts showing dependence of conductivity on two variables - voltage and the energy level position in a QD - which can be controlled by the plunger gate voltage. The finite Coulombic repulsion splits the density of states into two distinct maxima with the energy separation between them controlled by that parameter. It was also shown that an increase of either the value of the on-site Coulomb repulsion in a QD or the parameter of the Coulomb repulsion between the electrons in the QD and the contacts leads to an overall shift of the density of electronic states dependence toward higher energy values. Presence of the QD-lead interaction yields formation of a new pair of peaks in the differential conductance dependence. We also show that existence of four quantum states in a QD leads to abrupt changes in the density of states. These results could be beneficial for potential applications in nanotube-based amperometric sensors.

  6. ORA59 and EIN3 interaction couples jasmonate-ethylene synergistic action to antagonistic salicylic acid regulation of PDF expression.

    Science.gov (United States)

    He, Xiang; Jiang, Jishan; Wang, Chang-Quan; Dehesh, Katayoon

    2017-04-01

    Hormonal crosstalk is central for tailoring plant responses to the nature of challenges encountered. The role of antagonism between the two major defense hormones, salicylic acid (SA) and jasmonic acid (JA), and modulation of this interplay by ethylene (ET) in favor of JA signaling pathway in plant stress responses is well recognized, but the underlying mechanism is not fully understood. Here, we show the opposing function of two transcription factors, ethylene insensitive3 (EIN3) and EIN3-Like1 (EIL1), in SA-mediated suppression and JA-mediated activation of PLANT DEFENSIN1.2 (PDF1.2). This functional duality is mediated via their effect on protein, not transcript levels of the PDF1.2 transcriptional activator octadecanoid-responsive Arabidopsis59 (ORA59). Specifically, JA induces ORA59 protein levels independently of EIN3/EIL1, whereas SA reduces the protein levels dependently of EIN3/EIL1. Co-infiltration assays revealed nuclear co-localization of ORA59 and EIN3, and split-luciferase together with yeast-two-hybrid assays established their physical interaction. The functional ramification of the physical interaction is EIN3-dependent degradation of ORA59 by the 26S proteasome. These findings allude to SA-responsive reduction of ORA59 levels mediated by EIN3 binding to and targeting of ORA59 for degradation, thus nominating ORA59 pool as a coordination node for the antagonistic function of ET/JA and SA. © 2017 Institute of Botany, Chinese Academy of Sciences.

  7. Spin-spin interaction between polarized neutrons and polarized 27Al, 59Co, and 93Nb from dispersive optical model and coupled-channel analyses

    International Nuclear Information System (INIS)

    Nagadi, M.M.; Weisel, G.J.; Walter, R.L.; Delaroche, J.P.; Romain, P.

    2004-01-01

    Coupled-channel and dispersive-optical model analyses of published neutron scattering and reaction data for 27 Al, 59 Co, and 93 Nb at incident energies between 0.1 and 80 MeV have been performed. The resulting potentials are used to place constraints on the determination of the spin-spin interaction from published spin-spin cross-section measurements. For the three nuclei, the strength of the central real spin-spin potential, which was taken to have a surface plus volume shape, was found to be small. Volume integrals for this central potential component were determined to be in the 4-7 MeV fm 3 range and to decrease somewhat as mass number increases

  8. ψ(3S) and Υ(5S) Originating in Heavy Meson Molecules: A Coupled Channel Analysis Based on an Effective Vector Quark–Quark Interaction

    International Nuclear Information System (INIS)

    Matsuda, Y.; Sakai, M.; Hirano, M.

    2013-01-01

    In our previous coupled channel analysis based on the Cornell effective quark–quark interaction, it was indicated that the ψ(3S) solution corresponding to ψ(4040) originates from a D ∗ D¯ ∗ channel state. In this article, we report on a simultaneous analysis of the ψ - and Υ-family states. The most conspicuous outcome is a finding that the Υ(5S) solution corresponding to Υ(10860) originates from a B ∗ B¯ ∗ channel state, very much like ψ(3S). Some other characteristics of the result, including the induced very large S–D mixing and relation of some of the solutions with newly observed heavy quarkonia-like states are discussed. (author)

  9. Experimental Quantification of Pore-Scale Flow Phenomena in 2D Heterogeneous Porous Micromodels: Multiphase Flow Towards Coupled Solid-Liquid Interactions

    Science.gov (United States)

    Li, Y.; Kazemifar, F.; Blois, G.; Christensen, K. T.

    2017-12-01

    Geological sequestration of CO2 within saline aquifers is a viable technology for reducing CO2 emissions. Central to this goal is accurately predicting both the fidelity of candidate sites pre-injection of CO2 and its post-injection migration. Moreover, local fluid pressure buildup may cause activation of small pre-existing unidentified faults, leading to micro-seismic events, which could prove disastrous for societal acceptance of CCS, and possibly compromise seal integrity. Recent evidence shows that large-scale events are coupled with pore-scale phenomena, which necessitates the representation of pore-scale stress, strain, and multiphase flow processes in large-scale modeling. To this end, the pore-scale flow of water and liquid/supercritical CO2 is investigated under reservoir-relevant conditions, over a range of wettability conditions in 2D heterogeneous micromodels that reflect the complexity of a real sandstone. High-speed fluorescent microscopy, complemented by a fast differential pressure transmitter, allows for simultaneous measurement of the flow field within and the instantaneous pressure drop across the micromodels. A flexible micromodel is also designed and fabricated, to be used in conjunction with the micro-PIV technique, enabling the quantification of coupled solid-liquid interactions.

  10. Multiphase flow towards coupled solid-liquid interactions in 2D heterogeneous porous micromodels: a fluorescent microscopy and micro-PIV measurement at pore scale

    Science.gov (United States)

    Li, Yaofa; Kazemifar, Farzan; Blois, Gianluca; Christensen, Kenneth; Kenneth Christensen, Notre Dame Team

    2017-11-01

    Multiphase flow in porous media is relevant to a range of applications in the energy and environmental sectors. Recently, the interest has been renewed by geological storage of CO2 within saline aquifers. Central to this goal is predicting the fidelity of candidate sites pre-injection of CO2 and its post-injection migration. Moreover, local pressure buildup may cause micro-seismic events, which could prove disastrous, and possibly compromise seal integrity. Evidence shows that the large-scale events are coupled with pore-scale phenomena, necessitating the understanding of pore-scale stress, strain, and flow processes and their representation in large-scale modeling. To this end, the pore-scale flow of water and supercritical CO2 is investigated under reservoir-relevant conditions over a range of wettability conditions in 2D heterogeneous micromodels that reflect the complexity of real sandstone. High-speed fluorescent microscopy, complemented by a fast differential pressure transmitter, allows for simultaneous measurement of the flow field within and the instantaneous pressure drop across the micromodels. A flexible micromodel is also designed, to be used in conjunction with the micro-PIV technique, enabling the quantification of coupled solid-liquid interactions. This work was supported as part of the GSCO2, an EFRC funded by the US DOE, Office of Science, and partially supported by WPI-I2CNER.

  11. Interactive Influence on Void Swelling in 300 Series Stainless Steels of Coupled Gradients in Temperature and DPA Rate

    International Nuclear Information System (INIS)

    Garner, F.

    2007-01-01

    Full text of publication follows: Recently, experimental evidence has accumulated that demonstrates that the dependence of swelling in austenitic steels on dpa rate has been strongly underestimated. In development of swelling correlations for both fusion and fission reactor applications the dpa rate is frequently but inadvertently incorporated into the temperature dependence. This inability to separate the separate dependencies of dpa rate and temperature is closely associated with the coupling of gradients in neutron flux-spectra and irradiation temperature along the axial length of components, especially for relatively small cores. In order to demonstrate the separate action of dpa rate and temperature, previously unpublished swelling data are presented from hexagonal ducts, fuel pins and pressurized tubes irradiated in EBR-II, all possessing both axial and radial gradients in dpa rate. Annealed AISI 304 components were chosen to avoid complications of precipitation found in other alloys such as AISI 316 or PCA. Since this steel never develops multiple-peak swelling behavior and experiences very little precipitation at high dpa rates, it use in this effort is ideal for separation of environmental variables. It is demonstrated that the transient regime of void selling is increased by increasing dpa rate and by decreasing temperature. It is also shown that the combined effect of dpa rate and temperature distribution along the length of any given structural component produces a well defined, scatter-free 'swelling loop' vs. dpa that uniquely allows estimation and separation of the separate dependencies of swelling on temperature and dpa rate. One consequence of the derived flux dependence is that components subject to a dpa rate gradient in general suffer much less distortion than predicted by equations that do not explicitly incorporate a dependence on dpa rate. It is also shown that over a wide range of irradiation conditions the terminal steady-state swelling

  12. Coupled 2-dimensional cascade theory for noise and unsteady aerodynamics of blade row interaction in turbofans. Volume 1: Theory development and parametric studies

    Science.gov (United States)

    Hanson, Donald B.

    1994-01-01

    Typical analytical models for interaction between rotor and stator in a turbofan analyze the effect of wakes from the rotor impinging on the stator, producing unsteady loading, and thereby generating noise. Reflection/transmission characteristics of the rotor are sometimes added in a separate calculation. In those models, there is a one-to-one relationship between wake harmonics and noise harmonics; that is, the BPF (blade passing frequency) wake harmonic causes only the BPF noise harmonic, etc. This report presents a more complete model in which flow tangency boundary conditions are satisfied on two cascades in relative motion for several harmonics simultaneously. By an extension of S.N. Smith's code for two dimensional flat plate cascades, the noise generation/frequency scattering/blade row reflection problem is solved in a single matrix inversion. It is found that the BPF harmonic excitation of the stator scatters considerable energy in the higher BPF harmonics due to relative motion between the blade rows. Furthermore, when swirl between the rotor and stator is modeled, a 'mode trapping' effect occurs which explains observations on fans operating at rotational speeds below BFP cuton: the BPF mode amplifies between blade rows by multiple reflections but cannot escape to the inlet and exit ducts. However, energy scattered into higher harmonics does propagate and dominates the spectrum at two and three times BPF. This report presents the complete derivation of the theory, comparison with a previous (more limited) coupled rotor/stator interaction theory due to Kaji and Okazaki, exploration of the mode trapping phenomenon, and parametric studies showing the effects of vane/blade ratio and rotor/stator interaction. For generality, the analysis applies to stages where the rotor is either upstream or downstream of the stator and to counter rotation stages. The theory has been coded in a FORTRAN program called CUP2D, documented in Volume 2 of this report. It is

  13. Comparative analysis of function and interaction of transcription factors in nematodes: Extensive conservation of orthology coupled to rapid sequence evolution

    Directory of Open Access Journals (Sweden)

    Singh Rama S

    2008-08-01

    Full Text Available Abstract Background Much of the morphological diversity in eukaryotes results from differential regulation of gene expression in which transcription factors (TFs play a central role. The nematode Caenorhabditis elegans is an established model organism for the study of the roles of TFs in controlling the spatiotemporal pattern of gene expression. Using the fully sequenced genomes of three Caenorhabditid nematode species as well as genome information from additional more distantly related organisms (fruit fly, mouse, and human we sought to identify orthologous TFs and characterized their patterns of evolution. Results We identified 988 TF genes in C. elegans, and inferred corresponding sets in C. briggsae and C. remanei, containing 995 and 1093 TF genes, respectively. Analysis of the three gene sets revealed 652 3-way reciprocal 'best hit' orthologs (nematode TF set, approximately half of which are zinc finger (ZF-C2H2 and ZF-C4/NHR types and HOX family members. Examination of the TF genes in C. elegans and C. briggsae identified the presence of significant tandem clustering on chromosome V, the majority of which belong to ZF-C4/NHR family. We also found evidence for lineage-specific duplications and rapid evolution of many of the TF genes in the two species. A search of the TFs conserved among nematodes in Drosophila melanogaster, Mus musculus and Homo sapiens revealed 150 reciprocal orthologs, many of which are associated with important biological processes and human diseases. Finally, a comparison of the sequence, gene interactions and function indicates that nematode TFs conserved across phyla exhibit significantly more interactions and are enriched in genes with annotated mutant phenotypes compared to those that lack orthologs in other species. Conclusion Our study represents the first comprehensive genome-wide analysis of TFs across three nematode species and other organisms. The findings indicate substantial conservation of transcription

  14. Capillary electrophoresis coupled with electrochemiluminescence for determination of atomoxetine hydrochloride and the study on its interactions with three proteins.

    Science.gov (United States)

    Zeng, Hua-jin; Yang, Ran; Zhang, Ying; Li, Jian-jun; Qu, Ling-bo

    2015-03-01

    A simple, rapid and sensitive method for the determination of atomoxetine hydrochloride (AH) by capillary electrophoresis with electrochemiluminescence detection (CE-ECL) using tris(2,2'-bipyridyl) ruthenium (II) was developed. Under optimized conditions, the determinations of AH in capsules and rat plasmas and the study on its interactions with three plasma proteins, including bovine serum albumin, cytochrome c and myoglobin were performed successfully. Relative to some previous studies, in this paper the methodologies for the determination of AH in aqueous solution and spiked plasma systems were established, respectively. By comparing the difference between the two work curves of two systems, the matrix effect in plasma samples on the determination of AH by the CE-ECL method was discussed in detail. The results indicated that the effect of the matrix in plasma samples should not be ignored even if no obvious interference was found in the electropherograms and the establishment of method validation in complex samples by the CE-ECL method was necessary. Copyright © 2014 John Wiley & Sons, Ltd.

  15. Hurricane Matthew (2016) and its Storm Surge Inundation under Global Warming Scenarios: Application of an Interactively Coupled Atmosphere-Ocean Model

    Science.gov (United States)

    Jisan, M. A.; Bao, S.; Pietrafesa, L.; Pullen, J.

    2017-12-01

    An interactively coupled atmosphere-ocean model was used to investigate the impacts of future ocean warming, both at the surface and the layers below, on the track and intensity of a hurricane and its associated storm surge and inundation. The category-5 hurricane Matthew (2016), which made landfall on the South Carolina coast of the United States, was used for the case study. Future ocean temperature changes and sea level rise (SLR) were estimated based on the projection of Inter-Governmental Panel on Climate Change (IPCC)'s Representative Concentration Pathway scenarios RCP 2.6 and RCP 8.5. After being validated with the present-day observational data, the model was applied to simulate the changes in track, intensity, storm surge and inundation that Hurricane Matthew would cause under future climate change scenarios. It was found that a significant increase in hurricane intensity, storm surge water level, and inundation area for Hurricane Matthew under future ocean warming and SLR scenarios. For example, under the RCP 8.5 scenario, the maximum wind speed would increase by 17 knots (14.2%), the minimum sea level pressure would decrease by 26 hPa (2.85%), and the inundated area would increase by 401 km2 (123%). By including the effect of SLR for the middle-21st-century scenario, the inundated area will further increase by up to 49.6%. The increase in the hurricane intensity and the inundated area was also found for the RCP 2.6 scenario. The response of sea surface temperature was analyzed to investigate the change in intensity. A comparison was made between the impacts when only the sea surface warming is considered versus when both the sea surface and the underneath layers are considered. These results showed that even without the effect of SLR, the storm surge level and the inundated area would be higher due to the increased hurricane intensity under the influence of the future warmer ocean temperature. The coupled effect of ocean warming and SLR would cause the

  16. Density functional studies on the exchange interaction of a dinuclear Gd(iii)-Cu(ii) complex: method assessment, magnetic coupling mechanism and magneto-structural correlations.

    Science.gov (United States)

    Rajaraman, Gopalan; Totti, Federico; Bencini, Alessandro; Caneschi, Andrea; Sessoli, Roberta; Gatteschi, Dante

    2009-05-07

    Density functional calculations have been performed on a [Gd(iii)Cu(ii)] complex [L(1)CuGd(O(2)CCF(3))(3)(C(2)H(5)OH)(2)] () (where L(1) is N,N'-bis(3-ethoxy-salicylidene)-1,2-diamino-2-methylpropanato) with an aim of assessing a suitable functional within the DFT formalism to understand the mechanism of magnetic coupling and also to develop magneto-structural correlations. Encouraging results have been obtained in our studies where the application of B3LYP on the crystal structure of yields a ferromagnetic J value of -5.8 cm(-1) which is in excellent agreement with the experimental value of -4.42 cm(-1) (H = JS(Gd).S(Cu)). After testing varieties of functional for the method assessment we recommend the use of B3LYP with a combination of an effective core potential basis set. For all electron basis sets the relativistic effects should be incorporated either via the Douglas-Kroll-Hess (DKH) or zeroth-order regular approximation (ZORA) methods. A breakdown approach has been adopted where the calculations on several model complexes of have been performed. Their wave functions have been analysed thereafter (MO and NBO analysis) in order to gain some insight into the coupling mechanism. The results suggest, unambiguously, that the empty Gd(iii) 5d orbitals have a prominent role on the magnetic coupling. These 5d orbitals gain partial occupancy via Cu(ii) charge transfer as well as from the Gd(iii) 4f orbitals. A competing 4f-3d interaction associated with the symmetry of the complex has also been observed. The general mechanism hence incorporates both contributions and sets forth rather a prevailing mechanism for the 3d-4f coupling. The magneto-structural correlations reveal that there is no unique parameter which the J values are strongly correlated with, but an exponential relation to the J value found for the O-Cu-O-Gd dihedral angle parameter is the most credible correlation.

  17. Hydrophilic interaction liquid chromatography coupled to high-resolution mass spectrometry to determine artificial sweeteners in environmental waters.

    Science.gov (United States)

    Salas, Daniela; Borrull, Francesc; Fontanals, Núria; Marcé, Rosa Maria

    2015-06-01

    Artificial sweeteners are food additives employed as sugar substitutes which are now considered to be emerging organic contaminants. In the present study, a method is developed for the determination of a group of artificial sweeteners in environmental waters. Considering the polar and hydrophilic character of these compounds, hydrophilic interaction liquid chromatography is proposed for their separation as an alternative to traditional reversed-phase liquid chromatography. Two stationary phases with different chemistry were compared for this purpose. For the detection of the analytes, high-resolution mass spectrometry (Orbitrap) was employed to take advantage of its benefits in terms of reliable quantification and confirmation for the measurement of accurate masses. Solid-phase extraction was chosen as the sample treatment, in which the extract in a mixture of NH4OH:MeOH:ACN (1:4:15) was directly injected into the chromatographic system, simplifying the analytical procedure. The optimized method was validated on river and waste water samples. For example, in the case of effluent water samples, limits of detection ranged from 0.002 to 0.7 μg/L and limits of quantification ranged from 0.004 to 1.5 μg/L. Apparent (whole method) recoveries ranged from 57 to 74% with intra-day precision (%RSD, n = 5) ranging from 6 to 25%. The method was successfully applied to water samples from different rivers in Catalonia and different waste water treatment plants in Tarragona. Acesulfame, cyclamate, saccharine and sucralose were found in several samples.

  18. Contribution to the study of remedy solutions to uranium(molybdenum)/aluminium interactions: role of silicon addition to aluminium, study of coupled effects

    International Nuclear Information System (INIS)

    Allenou, J.

    2011-01-01

    In the project development and qualification program of a nuclear fuel with Low Enriched Uranium for Materials Testing Reactors, the dispersed U(Mo)/Al fuel is being developed due to its excellent stability during irradiation. However, in pile experiments showed that depending on the irradiation conditions (e.g. high burnup or high heat flux), an extensive interaction occurs between the fissile element U(Mo) and the Al based matrix resulting in swelling, which could eventually lead to a fuel plate failure. Among the ways to improve the behavior of the dispersed U(Mo) fuel, the solution now seen as the reference remedy by the entire scientific community is the addition of silicon into the aluminum matrix. In order to provide some understanding and optimizing the solution 'Si additions into Al matrix' under neutron irradiation, an out of pile study is performed on (i) the interaction mechanisms involved in the U(Mo)/Al (Si) system and (ii) the impact of the Si additions into the Al matrix on alternative solutions to the U(Mo)/Al interactions, namely the modification of the γ-U(Mo) fissile compound by adding a third element and/or modifying the interface between the γ-U(Mo) fissile compound and the matrix. This document provides a mechanistic description of the U(7Mo)/Al(Si) interaction for a range of Si content in Al between 2 and 10 wt.%, based on the multi-scale characterization of diffusion couples. The location of the Mo and its role in the reaction mechanisms are demonstrated. The influence of elements X = Y, Cu, Zr, Ti, Cr, on the U (Mo)/Al and U (Mo)/Al (Si) interactions mechanisms was then studied. It is shown that adding a third element to the U(Mo) alloy acts on the second order on diffusion kinetics and (micro)structure of the interaction layer compared to the addition of Si into Al. Finally, an alumina coating which shows a potential interest to improve the performance of the fuel has been developed. (author) [fr

  19. Magnetic interactions and magnetic anisotropy in exchange coupled 4f-3d systems: a case study of a heterodinuclear Ce3+-Fe3+ cyanide-bridged complex.

    Science.gov (United States)

    Sorace, Lorenzo; Sangregorio, Claudio; Figuerola, Albert; Benelli, Cristiano; Gatteschi, Dante

    2009-01-01

    We report here a detailed single-crystal EPR and magnetic study of a homologous series of complexes of the type Ln-M (Ln = La(III), Ce(III); M = Fe(III), Co(III)). We were able to obtain a detailed picture of the low-lying levels of Ce(III) and Fe(III) centres through the combined use of single-crystal EPR and magnetic susceptibility data. We show that classical ligand field theory can be of great help in rationalising the energies of the low-lying levels of both the transition-metal and rare-earth ions. The combined analysis of single-crystal EPR and magnetic data of the coupled system Ce-Fe confirmed the great complexity of the interactions involving rare-earth elements. With little uncertainty, it turned out clearly that the description of the interaction involving the lowest lying spin levels requires the introduction of the isotropic, anisotropic and antisymmetric terms.

  20. Study of the interaction of 6-mercaptopurine with protein by microdialysis coupled with LC and electrochemical detection based on functionalized multi-wall carbon nanotubes modified electrode.

    Science.gov (United States)

    Cao, Xu-Ni; Lin, Li; Zhou, Yu-Yan; Zhang, Wen; Shi, Guo-Yue; Yamamoto, Katsunobu; Jin, Li-Tong

    2003-07-14

    Microdialysis sampling coupled with liquid chromatography and electrochemical detection (LC-ECD) was developed and applied to study the interaction of 6-Mercaptopurine (6-MP) with bovine serum albumin (BSA). In the LC-ECD, the multi-wall carbon nanotubes fuctionalized with carboxylic groups modified electrode (MWNT-COOH CME) was used as the working electrode for the determination of 6-MP. The results indicated that this chemically modified electrode (CME) exhibited efficiently electrocatalytic oxidation for 6-MP with relatively high sensitivity, stability and long-life. The peak currents of 6-MP were linear to its concentrations ranging from 4.0 x 10(-7) to 1.0 x 10(-4) mol l(-1) with the calculated detection limit (S/N = 3) of 2.0 x 10(-7) mol l(-1). The method had been successfully applied to assess the association constant (K) and the number of the binding sites (n) on a BSA molecular, which calculated by Scatchard equation, were 3.97 x 10(3) mol(-1) l and 1.51, respectively. This method provided a fast, sensible and simple technique for the study of drug-protein interactions.

  1. The FAK–Arp2/3 interaction promotes leading edge advance and haptosensing by coupling nascent adhesions to lamellipodia actin

    Science.gov (United States)

    Swaminathan, Vinay; Fischer, R. S.; Waterman, Clare M.

    2016-01-01

    Cell migration is initiated in response to biochemical or physical cues in the environment that promote actin-mediated lamellipodial protrusion followed by the formation of nascent integrin adhesions (NAs) within the protrusion to drive leading edge advance. Although FAK is known to be required for cell migration through effects on focal adhesions, its role in NA formation and lamellipodial dynamics is unclear. Live-cell microscopy of FAK−/− cells with expression of phosphorylation deficient or a FERM-domain mutant deficient in Arp2/3 binding revealed a requirement for FAK in promoting the dense formation, transient stabilization, and timely turnover of NA within lamellipodia to couple actin-driven protrusion to adhesion and advance of the leading edge. Phosphorylation on Y397 of FAK promotes dense NA formation but is dispensable for transient NA stabilization and leading edge advance. In contrast, transient NA stabilization and advance of the cell edge requires FAK–Arp2/3 interaction, which promotes Arp2/3 localization to NA and reduces FAK activity. Haptosensing of extracellular matrix (ECM) concentration during migration requires the interaction between FAK and Arp2/3, whereas FAK phosphorylation modulates mechanosensing of ECM stiffness during spreading. Taken together, our results show that mechanistically separable functions of FAK in NA are required for cells to distinguish distinct properties of their environment during migration. PMID:26842895

  2. Simultaneous determination of the repertoire of classical neurotransmitters released from embryonal carcinoma stem cells using online microdialysis coupled with hydrophilic interaction chromatography–tandem mass spectrometry

    International Nuclear Information System (INIS)

    Tang, Ya-Bin; Sun, Fan; Teng, Lin; Li, Wen-Bin; An, Shi-Min; Zhang, Chun; Yang, Xin-Jie; Lv, Hao-Yu; Ding, Xu-Ping; Zhu, Liang

    2014-01-01

    Highlights: • An online MD-HILIC–MS/MS method for simultaneously measuring the repertoire of classical transmitters was developed and validated. • Hydrophilic interaction chromatography (HILIC) was successfully employed to online system. • Stable isotope labeled internal standards and authentic matrix have been applied to guarantee reliable results. • The method features simple procedure (no sample preparation), high recovery (≥73%), high accuracy (89.36% ≤ RE ≤ 116.89%), good reproducibility (2.18% ≤ RSD ≤ 14.56%), and sensitive limits of detection (2 pg for acetylcholine, serotonin, and glutamate, 10 pg for dopamine, norepinephrine, GABA, and glycine). - Abstract: Dynamic, continuous, and simultaneous multi-analysis of transmitters is important for the delineation of the complex interactions between the neuronal and intercellular communications. But the analysis of the whole repertoire of classical transmitters of diverse structure is challenging due to their different physico-chemical properties and to their high polarity feature which leads to poor retention in traditional reversed-phase columns during LC–MS analysis. Here, an online microdialysis coupled with hydrophilic interaction chromatography–tandem mass spectrometry (online MD-HILIC–MS/MS) detection method was developed for the simultaneous measurement of the repertoire of classical transmitters (acetylcholine, serotonin, dopamine, norepinephrine, glutamate, GABA, and glycine). Stable isotope labeled internal standards and authentic matrix have been applied to guarantee reliable results. The method was successfully employed to reveal the characteristics of transmitter release from embryonal carcinoma stem cells. The method features simple procedure (no sample preparation), high recovery (≥73%), high accuracy (89.36% ≤ RE ≤ 116.89%), good reproducibility (2.18% ≤ RSD ≤ 14.56%), and sensitive limits of detection (2 pg for acetylcholine, serotonin, and glutamate, 10 pg

  3. Simultaneous determination of the repertoire of classical neurotransmitters released from embryonal carcinoma stem cells using online microdialysis coupled with hydrophilic interaction chromatography–tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Ya-Bin [Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Sun, Fan [Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Teng, Lin [Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Department of Cardiology and Institute of Cardiovascular Diseases, The First College of Clinical Medical Sciences, China Three Gorges University, Yichang 443000, Hubei (China); Li, Wen-Bin; An, Shi-Min [Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Zhang, Chun; Yang, Xin-Jie; Lv, Hao-Yu; Ding, Xu-Ping [Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Zhu, Liang, E-mail: zhuliang17@gmail.com [Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); and others

    2014-11-07

    Highlights: • An online MD-HILIC–MS/MS method for simultaneously measuring the repertoire of classical transmitters was developed and validated. • Hydrophilic interaction chromatography (HILIC) was successfully employed to online system. • Stable isotope labeled internal standards and authentic matrix have been applied to guarantee reliable results. • The method features simple procedure (no sample preparation), high recovery (≥73%), high accuracy (89.36% ≤ RE ≤ 116.89%), good reproducibility (2.18% ≤ RSD ≤ 14.56%), and sensitive limits of detection (2 pg for acetylcholine, serotonin, and glutamate, 10 pg for dopamine, norepinephrine, GABA, and glycine). - Abstract: Dynamic, continuous, and simultaneous multi-analysis of transmitters is important for the delineation of the complex interactions between the neuronal and intercellular communications. But the analysis of the whole repertoire of classical transmitters of diverse structure is challenging due to their different physico-chemical properties and to their high polarity feature which leads to poor retention in traditional reversed-phase columns during LC–MS analysis. Here, an online microdialysis coupled with hydrophilic interaction chromatography–tandem mass spectrometry (online MD-HILIC–MS/MS) detection method was developed for the simultaneous measurement of the repertoire of classical transmitters (acetylcholine, serotonin, dopamine, norepinephrine, glutamate, GABA, and glycine). Stable isotope labeled internal standards and authentic matrix have been applied to guarantee reliable results. The method was successfully employed to reveal the characteristics of transmitter release from embryonal carcinoma stem cells. The method features simple procedure (no sample preparation), high recovery (≥73%), high accuracy (89.36% ≤ RE ≤ 116.89%), good reproducibility (2.18% ≤ RSD ≤ 14.56%), and sensitive limits of detection (2 pg for acetylcholine, serotonin, and glutamate, 10 pg

  4. Submesoscale features and their interaction with fronts and internal tides in a high-resolution coupled atmosphere-ocean-wave model of the Bay of Bengal

    Science.gov (United States)

    Jensen, Tommy G.; Shulman, Igor; Wijesekera, Hemantha W.; Anderson, Stephanie; Ladner, Sherwin

    2018-03-01

    Large freshwater fluxes into the Bay of Bengal by rainfall and river discharges result in strong salinity fronts in the bay. In this study, a high-resolution coupled atmosphere-ocean-wave model with comprehensive physics is used to model the weather, ocean circulation, and wave field in the Bay of Bengal. Our objective is to explore the submesoscale activity that occurs in a realistic coupled model that resolves mesoscales and allows part of the submesoscale field. Horizontal resolution in the atmosphere varies from 2 to 6 km and is 13 km for surface waves, while the ocean model is submesoscale permitting with resolutions as high as 1.5 km and a vertical resolution of 0.5 m in the upper 10 m. In this paper, three different cases of oceanic submesoscale features are discussed. In the first case, heavy rainfall and intense downdrafts produced by atmospheric convection are found to force submesoscale currents, temperature, and salinity anomalies in the oceanic mixed layer and impact the mesoscale flow. In a second case, strong solitary-like waves are generated by semidiurnal tides in the Andaman Sea and interact with mesoscale flows and fronts and affect submesoscale features generated along fronts. A third source of submesoscale variability is found further north in the Bay of Bengal where river outflows help maintain strong salinity gradients throughout the year. For that case, a comparison with satellite observations of sea surface height anomalies, sea surface temperature, and chlorophyll shows that the model captures the observed mesoscale eddy features of the flow field, but in addition, submesoscale upwelling and downwelling patterns associated with ageostrophic secondary circulations along density fronts are also captured by the model.

  5. Methodological study of the diffusion of interacting cations through clays. Application: experimental tests and simulation of coupled chemistry-diffusion transport of alkaline ions through a synthetical bentonite

    International Nuclear Information System (INIS)

    Melkior, Th.

    2000-01-01

    The subject of this work deals with the project of underground disposal of radioactive wastes in deep geological formations. It concerns the study of the migration of radionuclides through clays. In these materials, the main transport mechanism is assumed to be diffusion under natural conditions. Therefore, some diffusion experiments are conducted. With interacting solutes which present a strong affinity for the material, the duration of these tests will be too long, for the range of concentrations of interest. An alternative is to determine on one hand the geochemical retention properties using batch tests and crushed rock samples and, on the other hand, to deduce the transport parameters from diffusion tests realised with a non-interacting tracer, tritiated water. These data are then used to simulate the migration of the reactive elements with a numerical code which can deal with coupled chemistry-diffusion equations. The validity of this approach is tested by comparing the numerical simulations with the results of diffusion experiments of cations through a clay. The subject is investigated in the case of the diffusion of cesium, lithium and sodium through a compacted sodium bentonite. The diffusion tests are realised with the through-diffusion method. The comparison between the experimental results and the simulations shows that the latter tends to under estimate the propagation of the considered species. The differences could be attributed to surface diffusion and to a decrease of the accessibility to the sites of fixation of the bentonite, from the conditions of clay suspensions in batch tests to the situation of compacted samples. The influence of the experimental apparatus used during the diffusion tests on the results of the measurement has also been tested. It showed that these apparatus have to be taken into consideration when the experimental data are interpreted. A specific model has been therefore developed with the numerical code CASTEM 2000. (author)

  6. Tensor contraction engine: Abstraction and automated parallel implementation of configuration-interaction, coupled-cluster, and many-body perturbation theories

    International Nuclear Information System (INIS)

    Hirata, So

    2003-01-01

    We develop a symbolic manipulation program and program generator (Tensor Contraction Engine or TCE) that automatically derives the working equations of a well-defined model of second-quantized many-electron theories and synthesizes efficient parallel computer programs on the basis of these equations. Provided an ansatz of a many-electron theory model, TCE performs valid contractions of creation and annihilation operators according to Wick's theorem, consolidates identical terms, and reduces the expressions into the form of multiple tensor contractions acted by permutation operators. Subsequently, it determines the binary contraction order for each multiple tensor contraction with the minimal operation and memory cost, factorizes common binary contractions (defines intermediate tensors), and identifies reusable intermediates. The resulting ordered list of binary tensor contractions, additions, and index permutations is translated into an optimized program that is combined with the NWChem and UTChem computational chemistry software packages. The programs synthesized by TCE take advantage of spin symmetry, Abelian point-group symmetry, and index permutation symmetry at every stage of calculations to minimize the number of arithmetic operations and storage requirement, adjust the peak local memory usage by index range tiling, and support parallel I/O interfaces and dynamic load balancing for parallel executions. We demonstrate the utility of TCE through automatic derivation and implementation of parallel programs for various models of configuration-interaction theory (CISD, CISDT, CISDTQ), many-body perturbation theory[MBPT(2), MBPT(3), MBPT(4)], and coupled-cluster theory (LCCD, CCD, LCCSD, CCSD, QCISD, CCSDT, and CCSDTQ)

  7. Hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry for highly rapid and sensitive analysis of underivatized amino acids in functional foods.

    Science.gov (United States)

    Zhou, Guisheng; Pang, Hanqing; Tang, Yuping; Yao, Xin; Mo, Xuan; Zhu, Shaoqing; Guo, Sheng; Qian, Dawei; Qian, Yefei; Su, Shulan; Zhang, Li; Jin, Chun; Qin, Yong; Duan, Jin-ao

    2013-05-01

    This work presented a new analytical methodology based on hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry in multiple-reaction monitoring mode for analysis of 24 underivatized free amino acids (FAAs) in functional foods. The proposed method was first reported and validated by assessing the matrix effects, linearity, limit of detections and limit of quantifications, precision, repeatability, stability and recovery of all target compounds, and it was used to determine the nutritional substances of FAAs in ginkgo seeds and further elucidate the nutritional value of this functional food. The result showed that ginkgo seed turned out to be a good source of FAAs with high levels of several essential FAAs and to have a good nutritional value. Furthermore, the principal component analysis was performed to classify the ginkgo seed samples on the basis of 24 FAAs. As a result, the samples could be mainly clustered into three groups, which were similar to areas classification. Overall, the presented method would be useful for the investigation of amino acids in edible plants and agricultural products.

  8. Ion beam induced modification of exchange interaction and spin-orbit coupling in the Co2FeSi Heusler compound

    International Nuclear Information System (INIS)

    Hamrle, J; Blomeier, S; Gaier, O; Hillebrands, B; Schneider, H; Jakob, G; Reuscher, B; Brodyanski, A; Kopnarski, M; Postava, K; Felser, C

    2007-01-01

    A Co 2 FeSi (CFS) film with L2 1 structure was irradiated with different fluences of 30 keV Ga + ions. Structural modifications were subsequently studied using the longitudinal (LMOKE) and quadratic (QMOKE) magneto-optical Kerr effect. Both the coercivity and the LMOKE amplitude were found to show a similar behaviour upon irradiation: they are nearly constant up to ion fluences of ∼6 x 10 15 ion cm -2 , while they decrease with further increasing fluences and finally vanish at a fluence of ∼9 x 10 16 ion cm -2 , when the sample becomes paramagnetic. However, contrary to this behaviour, the QMOKE signal nearly vanishes even for the smallest applied fluence of 3 x 10 14 ion cm -2 . We attribute this reduction of the QMOKE signal to an irradiation-induced degeneration of second or higher order spin-orbit coupling, which already happens at small fluences of 30 keV Ga + ions. On the other hand, the reduction of coercivity and LMOKE signal with high ion fluences is probably caused by a reduction of the exchange interaction within the film material

  9. On-line solid-phase extraction coupled to hydrophilic interaction chromatography-mass spectrometry for the determination of polar drugs.

    Science.gov (United States)

    Fontanals, Núria; Marcé, Rosa M; Borrull, Francesc

    2011-09-02

    The present study describes the first fully automated method based on on-line solid-phase extraction (SPE) coupled to hydrophilic interaction chromatography-electrospray-mass spectrometry (HILIC-(ESI)MS) to determine a group of polar drugs that includes illicit drugs (such as cocaine, morphine, codeine and metabolites) and pharmaceuticals in environmental water samples. The SPE was performed using a highly retentive polymeric sorbent. The HILIC separation was optimised and the initial high organic content of the chromatographic mobile phase, was also suitable for the proper on-line elution of the analytes retained in the SPE column and for enhancing the ESI ionisation efficiency. This method allows the loading of samples of up to 250ml of ultrapure water or 10ml of environmental water samples spiked at low ngl(-1) levels of the analytes. The method yields near 100% recoveries for all the analytes. The method was also validated with environmental water samples with linear ranges from 5 to 1000ngl(-1) and limits of detection ≤2ngl(-1) for most of the compounds. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. Characterization of product-related low molecular weight impurities in therapeutic monoclonal antibodies using hydrophilic interaction chromatography coupled with mass spectrometry.

    Science.gov (United States)

    Wang, Shunhai; Liu, Anita P; Yan, Yuetian; Daly, Thomas J; Li, Ning

    2018-05-30

    Traditional SDS-PAGE method and its modern equivalent CE-SDS method are both widely applied to assess the purity of therapeutic monoclonal antibody (mAb) drug products. However, structural identification of low molecular weight (LMW) impurities using those methods has been challenging and largely based on empirical knowledges. In this paper, we present that hydrophilic interaction chromatography (HILIC) coupled with mass spectrometry analysis is a novel and orthogonal method to characterize such LMW impurities present within a purified mAb drug product sample. We show here that after removal of N-linked glycans, the HILIC method separates mAb-related LMW impurities with a size-based elution order. The subsequent mass measurement from a high-resolution accurate mass spectrometer provides direct and unambiguous identification of a variety of low-abundance LMW impurities within a single LC-MS analysis. Free light chain, half antibody, H2L species (antibody possessing a single light chain) and protein backbone-truncated species can all be confidently identified and elucidated in great detail, including the truncation sites and associated post-translational modifications. It is worth noting that this study provides the first example where the H2L species can be directly detected in a mAb drug product sample by intact mass analysis without prior enrichment. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  11. Interacting Effects of Light and Iron Availability on the Coupling of Photosynthetic Electron Transport and CO2-Assimilation in Marine Phytoplankton.

    Science.gov (United States)

    Schuback, Nina; Schallenberg, Christina; Duckham, Carolyn; Maldonado, Maria T; Tortell, Philippe D

    2015-01-01

    Iron availability directly affects photosynthesis and limits phytoplankton growth over vast oceanic regions. For this reason, the availability of iron is a crucial variable to consider in the development of active chlorophyll a fluorescence based estimates of phytoplankton primary productivity. These bio-optical approaches require a conversion factor to derive ecologically-relevant rates of CO2-assimilation from estimates of electron transport in photosystem II. The required conversion factor varies significantly across phytoplankton taxa and environmental conditions, but little information is available on its response to iron limitation. In this study, we examine the role of iron limitation, and the interacting effects of iron and light availability, on the coupling of photosynthetic electron transport and CO2-assimilation in marine phytoplankton. Our results show that excess irradiance causes increased decoupling of carbon fixation and electron transport, particularly under iron limiting conditions. We observed that reaction center II specific rates of electron transport (ETR(RCII), mol e- mol RCII(-1) s(-1)) increased under iron limitation, and we propose a simple conceptual model for this observation. We also observed a strong correlation between the derived conversion factor and the expression of non-photochemical quenching. Utilizing a dataset from in situ phytoplankton assemblages across a coastal--oceanic transect in the Northeast subarctic Pacific, this relationship was used to predict ETR(RCII): CO2-assimilation conversion factors and carbon-based primary productivity from FRRF data, without the need for any additional measurements.

  12. Analysis of iminosugars and other low molecular weight carbohydrates in Aglaonema sp. extracts by hydrophilic interaction liquid chromatography coupled to mass spectrometry.

    Science.gov (United States)

    Rodríguez-Sánchez, S; García-Sarrió, M J; Quintanilla-López, J E; Soria, A C; Sanz, M L

    2015-12-04

    A method by hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry (HILIC-MS(2)) has been successfully developed for the simultaneous analysis of bioactive iminosugars and other low molecular weight carbohydrates in Aglaonema leaf extracts. Among other experimental chromatographic conditions, mobile phase eluents, additives and column temperature were evaluated in terms of retention time, resolution, peak width and symmetry provided for target carbohydrates. In general, narrow peaks (wh: 0.2-0.6min) with good symmetry (As: 0.9-1.3) and excellent resolution (Rs>1.8) were obtained for iminosugars using an acetonitrile:water gradient with 5mM ammonium acetate in both eluents at 55°C. Tandem mass spectra were used to confirm the presence of previously detected iminosugars in Aglaonema extracts and to tentatively identify for the first time others such as miglitol isomer, glycosyl-miglitol isomers and glycosyl-DMDP isomers. Concentration of total iminosugars varied from 1.35 to 2.84mgg(-1) in the extracts of the different Aglaonema samples analyzed. To the best of our knowledge, this is the first time that a HILIC-MS(2) method has been proposed for the simultaneous analysis of iminosugars and other low molecular weight carbohydrates of Aglaonema sp. extracts. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Hydrophilic interaction chromatography coupled matrix assisted laser desorption/ionization mass spectrometry for molecular analysis of organic compounds in medicines, tea, and coffee.

    Science.gov (United States)

    Wang, Ren-Qi; Bao, Kai; Croué, Jean-Philippe; Ng, Siu Choon

    2013-11-21

    Natural occurring organic compounds from food, natural organic matter, as well as metabolic products have received intense attention in current chemical and biological studies. Examination of unknown compounds in complex sample matrices is hampered by the limited choices for data readout and molecular elucidation. Herein, we report a generic method of hydrophilic interaction chromatography (HILIC) coupled with matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) for the rapid characterization of ingredients in pharmaceutical compounds, tea, and coffee. The analytes were first fractionated using a cationic HILIC column prior to MALDI-MS analyses. It was found that the retention times of a compound arising from different samples were consistent under the same conditions. Accordingly, molecules can be readily characterized by both the mass and chromatographic retention time. The retention behaviors of acidic and basic compounds on the cationic HILIC column were found to be significantly influenced by the pH of mobile phases, whereas neutral compounds depicted a constant retention time at different pH. The general HILIC-MALDI-MS method is feasible for fast screening of naturally occurring organic compounds. A series of homologs can be determined if they have the same retention behavior. Their structural features can be elucidated by considering their mass differences and hydrophilic properties as determined by HILIC chromatogram.

  14. Hydrophilic interaction ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry for determination of nucleotides, nucleosides and nucleobases in Ziziphus plants.

    Science.gov (United States)

    Guo, Sheng; Duan, Jin-ao; Qian, Dawei; Wang, Hanqing; Tang, Yuping; Qian, Yefei; Wu, Dawei; Su, Shulan; Shang, Erxin

    2013-08-02

    In this study, a rapid and sensitive analytical method was developed for the determination of 20 nucleobases, nucleosides and nucleotides in Ziziphus plants at trace levels by using hydrophilic interaction ultra-high performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (HILIC-UHPLC-TQ-MS/MS) in multiple-reaction monitoring (MRM) mode. Under the optimized chromatographic conditions, good separation for 20 target compounds were obtained on a UHPLC Amide column with sub-2μm particles within 10min. The overall LODs and LOQs were between 0.11-3.12ngmL(-1) and 0.29-12.48ngmL(-1) for the 20 analytes, respectively. It is the first report about simultaneous analysis of nucleobases, nucleosides and nucleotides in medicinal plants using HILIC-UHPLC-TQ-MS/MS method, which affords good linearity, precision, repeatability and accuracy. The developed method was successfully applied to Ziziphus plant (Z. jujuba, Z. jujuba var. spinosa and Z. mauritiana) samples. The analysis showed that the fruits and leaves of Ziziphus plants are rich in nucleosides and nucleobases as well as nucleotides, and could be selected as the healthy food resources. Our results in present study suggest that HILIC-UHPLC-TQ-MS/MS method could be employed as a useful tool for quality assessment of the samples from the Ziziphus plants as well as other medicinal plants or food samples using nucleotides, nucleosides and nucleobases as markers. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Combinations of coupled cluster, density functionals, and the random phase approximation for describing static and dynamic correlation, and van der Waals interactions

    Science.gov (United States)

    Garza, Alejandro J.; Bulik, Ireneusz W.; Alencar, Ana G. Sousa; Sun, Jianwei; Perdew, John P.; Scuseria, Gustavo E.

    2016-04-01

    Contrary to standard coupled cluster doubles (CCD) and Brueckner doubles (BD), singlet-paired analogues of CCD and BD (denoted here as CCD0 and BD0) do not break down when static correlation is present, but neglect substantial amounts of dynamic correlation. In fact, CCD0 and BD0 do not account for any contributions from multielectron excitations involving only same-spin electrons at all. We exploit this feature to add - without introducing double counting, self-interaction, or increase in cost - the missing correlation to these methods via meta-GGA (generalised gradient approximation) density functionals (Tao-Perdew-Staroverov-Scuseria and strongly constrained and appropriately normed). Furthermore, we improve upon these CCD0+DFT blends by invoking range separation: the short- and long-range correlations absent in CCD0/BD0 are evaluated with density functional theory and the direct random phase approximation, respectively. This corrects the description of long-range van der Waals forces. Comprehensive benchmarking shows that the combinations presented here are very accurate for weakly correlated systems, while also providing a reasonable description of strongly correlated problems without resorting to symmetry breaking.

  16. Competition between drag and Coulomb interactions in turbulent particle-laden flows using a coupled-fluid-Ewald-summation based approach

    Science.gov (United States)

    Yao, Yuan; Capecelatro, Jesse

    2018-03-01

    We present a numerical study on inertial electrically charged particles suspended in a turbulent carrier phase. Fluid-particle interactions are accounted for in an Eulerian-Lagrangian (EL) framework and coupled to a Fourier-based Ewald summation method, referred to as the particle-particle-particle-mesh (P3M ) method, to accurately capture short- and long-range electrostatic forces in a tractable manner. The EL P3M method is used to assess the competition between drag and Coulomb forces for a range of Stokes numbers and charge densities. Simulations of like- and oppositely charged particles suspended in a two-dimensional Taylor-Green vortex and three-dimensional homogeneous isotropic turbulence are reported. It is found that even in dilute suspensions, the short-range electric potential plays an important role in flows that admit preferential concentration. Suspensions of oppositely charged particles are observed to agglomerate in the form of chains and rings. Comparisons between the particle-mesh method typically employed in fluid-particle calculations and P3M are reported, in addition to one-point and two-point statistics to quantify the level of clustering as a function of Reynolds number, Stokes number, and nondimensional electric settling velocity.

  17. Interacting Effects of Light and Iron Availability on the Coupling of Photosynthetic Electron Transport and CO2-Assimilation in Marine Phytoplankton.

    Directory of Open Access Journals (Sweden)

    Nina Schuback

    Full Text Available Iron availability directly affects photosynthesis and limits phytoplankton growth over vast oceanic regions. For this reason, the availability of iron is a crucial variable to consider in the development of active chlorophyll a fluorescence based estimates of phytoplankton primary productivity. These bio-optical approaches require a conversion factor to derive ecologically-relevant rates of CO2-assimilation from estimates of electron transport in photosystem II. The required conversion factor varies significantly across phytoplankton taxa and environmental conditions, but little information is available on its response to iron limitation. In this study, we examine the role of iron limitation, and the interacting effects of iron and light availability, on the coupling of photosynthetic electron transport and CO2-assimilation in marine phytoplankton. Our results show that excess irradiance causes increased decoupling of carbon fixation and electron transport, particularly under iron limiting conditions. We observed that reaction center II specific rates of electron transport (ETR(RCII, mol e- mol RCII(-1 s(-1 increased under iron limitation, and we propose a simple conceptual model for this observation. We also observed a strong correlation between the derived conversion factor and the expression of non-photochemical quenching. Utilizing a dataset from in situ phytoplankton assemblages across a coastal--oceanic transect in the Northeast subarctic Pacific, this relationship was used to predict ETR(RCII: CO2-assimilation conversion factors and carbon-based primary productivity from FRRF data, without the need for any additional measurements.

  18. Interacting Effects of Light and Iron Availability on the Coupling of Photosynthetic Electron Transport and CO2-Assimilation in Marine Phytoplankton

    Science.gov (United States)

    Schuback, Nina; Schallenberg, Christina; Duckham, Carolyn; Maldonado, Maria T.; Tortell, Philippe D.

    2015-01-01

    Iron availability directly affects photosynthesis and limits phytoplankton growth over vast oceanic regions. For this reason, the availability of iron is a crucial variable to consider in the development of active chlorophyll a fluorescence based estimates of phytoplankton primary productivity. These bio-optical approaches require a conversion factor to derive ecologically-relevant rates of CO2-assimilation from estimates of electron transport in photosystem II. The required conversion factor varies significantly across phytoplankton taxa and environmental conditions, but little information is available on its response to iron limitation. In this study, we examine the role of iron limitation, and the interacting effects of iron and light availability, on the coupling of photosynthetic electron transport and CO2-assimilation in marine phytoplankton. Our results show that excess irradiance causes increased decoupling of carbon fixation and electron transport, particularly under iron limiting conditions. We observed that reaction center II specific rates of electron transport (ETRRCII, mol e- mol RCII-1 s-1) increased under iron limitation, and we propose a simple conceptual model for this observation. We also observed a strong correlation between the derived conversion factor and the expression of non-photochemical quenching. Utilizing a dataset from in situ phytoplankton assemblages across a coastal – oceanic transect in the Northeast subarctic Pacific, this relationship was used to predict ETRRCII: CO2-assimilation conversion factors and carbon-based primary productivity from FRRF data, without the need for any additional measurements. PMID:26171963

  19. Hydrophilic interaction chromatography coupled matrix assisted laser desorption/ionization mass spectrometry for molecular analysis of organic compounds in medicines, tea, and coffee

    KAUST Repository

    Wang, Renqi

    2013-01-01

    Natural occurring organic compounds from food, natural organic matter, as well as metabolic products have received intense attention in current chemical and biological studies. Examination of unknown compounds in complex sample matrices is hampered by the limited choices for data readout and molecular elucidation. Herein, we report a generic method of hydrophilic interaction chromatography (HILIC) coupled with matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) for the rapid characterization of ingredients in pharmaceutical compounds, tea, and coffee. The analytes were first fractionated using a cationic HILIC column prior to MALDI-MS analyses. It was found that the retention times of a compound arising from different samples were consistent under the same conditions. Accordingly, molecules can be readily characterized by both the mass and chromatographic retention time. The retention behaviors of acidic and basic compounds on the cationic HILIC column were found to be significantly influenced by the pH of mobile phases, whereas neutral compounds depicted a constant retention time at different pH. The general HILIC-MALDI-MS method is feasible for fast screening of naturally occurring organic compounds. A series of homologs can be determined if they have the same retention behavior. Their structural features can be elucidated by considering their mass differences and hydrophilic properties as determined by HILIC chromatogram. © 2013 The Royal Society of Chemistry.

  20. The heterotrimeric G protein Gβ1 interacts with the catalytic subunit of protein phosphatase 1 and modulates G protein-coupled receptor signaling in platelets.

    Science.gov (United States)

    Pradhan, Subhashree; Khatlani, Tanvir; Nairn, Angus C; Vijayan, K Vinod

    2017-08-11

    Thrombosis is caused by the activation of platelets at the site of ruptured atherosclerotic plaques. This activation involves engagement of G protein-coupled receptors (GPCR) on platelets that promote their aggregation. Although it is known that protein kinases and phosphatases modulate GPCR signaling, how serine/threonine phosphatases integrate with G protein signaling pathways is less understood. Because the subcellular localization and substrate specificity of the catalytic subunit of protein phosphatase 1 (PP1c) is dictated by PP1c-interacting proteins, here we sought to identify new PP1c interactors. GPCRs signal via the canonical heterotrimeric Gα and Gβγ subunits. Using a yeast two-hybrid screen, we discovered an interaction between PP1cα and the heterotrimeric G protein Gβ 1 subunit. Co-immunoprecipitation studies with epitope-tagged PP1c and Gβ 1 revealed that Gβ 1 interacts with the PP1c α, β, and γ1 isoforms. Purified PP1c bound to recombinant Gβ 1 -GST protein, and PP1c co-immunoprecipitated with Gβ 1 in unstimulated platelets. Thrombin stimulation of platelets induced the dissociation of the PP1c-Gβ 1 complex, which correlated with an association of PP1c with phospholipase C β3 (PLCβ3), along with a concomitant dephosphorylation of the inhibitory Ser 1105 residue in PLCβ3. siRNA-mediated depletion of GNB1 (encoding Gβ 1 ) in murine megakaryocytes reduced protease-activated receptor 4, activating peptide-induced soluble fibrinogen binding. Thrombin-induced aggregation was decreased in PP1cα -/- murine platelets and in human platelets treated with a small-molecule inhibitor of Gβγ. Finally, disruption of PP1c-Gβ 1 complexes with myristoylated Gβ 1 peptides containing the PP1c binding site moderately decreased thrombin-induced human platelet aggregation. These findings suggest that Gβ 1 protein enlists PP1c to modulate GPCR signaling in platelets.

  1. Strong and anisotropic superexchange in the single-molecule magnet (SMM) [MnIII(6)OsIII]3+: promoting SMM behavior through 3d-5d transition metal substitution.

    Science.gov (United States)

    Hoeke, Veronika; Stammler, Anja; Bögge, Hartmut; Schnack, Jürgen; Glaser, Thorsten

    2014-01-06

    The reaction of the in situ generated trinuclear triplesalen complex [(talent-Bu2)MnIII3(solv)n]3+ with (Ph4P)3[OsIII(CN)6] and NaClO4·H2O affords [MnIII6OsIII](ClO4)3 (= [{(talent-Bu2)MnIII3}2{OsIII(CN)6}](ClO4)3) in the presence of the oxidizing agent [(tacn)2NiIII](ClO4)3 (tacn =1,4,7-triazacyclononane), while the reaction of [(talent-Bu2)MnIII3(solv)n]3+ with K4[OsII(CN)6] and NaClO4·H2O yields [MnIII6OsII](ClO4)2 under an argon atmosphere. The molecular structure of [MnIII6OsIII]3+ as determined by single-crystal X-ray diffraction is closely related to the already published [MnIII6Mc]3+ complexes (Mc = CrIII, FeIII, CoIII, MnIII). The half-wave potential of the OsIII/OsII couple is E1/2 = 0.07 V vs Fc+/Fc. The FT-IR and electronic absorption spectra of [MnIII6OsII]2+ and [MnIII6OsIII]3+ exhibit distinct features of dicationic and tricationic [MnIII6Mc]n+ complexes, respectively. The dc magnetic data (μeff vs T, M vs B, and VTVH) of [MnIII6OsII]2+ are successfully simulated by a full-matrix diagonalization of a spin-Hamiltonian including isotropic exchange, zero-field splitting with full consideration of the relative orientation of the D-tensors, and Zeeman interaction, indicating antiferromagnetic MnIII–MnIII interactions within the trinuclear triplesalen subunits (JMn–Mn(1) = −(0.53 ± 0.01) cm–1, Ĥex = −2∑iSMM [MnIII6OsIII]3+ compared to the 3d analogue [MnIII6FeIII]3+ due to the stronger and anisotropic Mc–MnIII exchange interaction.

  2. Symmetry-adapted-cluster configuration-interaction and equation-of-motion coupled-cluster studies of electronically excited states of copper tetrachloride and copper tetrabromide dianions

    International Nuclear Information System (INIS)

    Ehara, Masahiro; Piecuch, Piotr; Lutz, Jesse J.; Gour, Jeffrey R.

    2012-01-01

    Graphical abstract: Electronically excited states of CuCl 4 2- and CuBr 4 2- are determined using the scalar relativistic symmetry-adapted-cluster configuration-interaction and equation-of-motion coupled-cluster calculations. The results are compared with experimental spectra. Highlights: ► Electronic spectra of CuCl 4 2- and CuBr 4 2- are examined by SAC-CI and EOMCC methods. ► Relativistic SAC-CI and EOMCC results are compared with experimental spectra. ► An assignment of bands in the CuCl 4 2- and CuBr 4 2- absorption spectra is obtained. ► Relativistic effects affect excitation energies and ground-state geometries. ► The effect of relativity on the oscillator strengths is generally small. - Abstract: The valence excitation spectra of the copper tetrachloride and copper tetrabromide open-shell dianions, CuCl 4 2- and CuBr 4 2- , respectively, are investigated by a variety of symmetry-adapted-cluster configuration-interaction (SAC-CI) and equation-of-motion coupled-cluster (EOMCC) methods. The valence excited states of the CuCl 4 2- and CuBr 4 2- species that correspond to transitions from doubly occupied molecular orbitals (MOs) to a singly occupied MO (SOMO), for which experimental spectra are available, are examined with the ionized (IP) variants of the SAC-CI and EOMCC methods. The higher-energy excited states of CuCl 4 2- and CuBr 4 2- that correspond to transitions from SOMO to unoccupied MOs, which have not been characterized experimentally, are determined using the electron-attached (EA) SAC-CI and EOMCC approaches. An emphasis is placed on the scalar relativistic SAC-CI and EOMCC calculations based on the spin-free part of the second-order Douglass–Kroll–Hess Hamiltonian (DKH2) and on a comparison of the results of the IP and EA SAC-CI and EOMCC calculations with up to 2-hole-1-particle (2h-1p) and 2-particle-1-hole (2p-1h) excitations, referred to as the IP-SAC-CI SD-R and IP-EOMCCSD(2h-1p) methods in the IP case and EA-SAC-CI SD-R and EA

  3. Tunneling Kinetics and Nonadiabatic Proton-Coupled Electron Transfer in Proteins: The Effect of Electric Fields and Anharmonic Donor-Acceptor Interactions.

    Science.gov (United States)

    Salna, Bridget; Benabbas, Abdelkrim; Russo, Douglas; Champion, Paul M

    2017-07-20

    A proper description of proton donor-acceptor (D-A) distance fluctuations is crucial for understanding tunneling in proton-coupled electron transport (PCET). The typical harmonic approximation for the D-A potential results in a Gaussian probability distribution, which does not appropriately reflect the electronic repulsion forces that increase the energetic cost of sampling shorter D-A distances. Because these shorter distances are the primary channel for thermally activated tunneling, the analysis of tunneling kinetics depends sensitively on the inherently anharmonic nature of the D-A interaction. Thus, we have used quantum chemical calculations to account for the D-A interaction and developed an improved model for the analysis of experimental tunneling kinetics. Strong internal electric fields are also considered and found to contribute significantly to the compressive forces when the D-A distance distribution is positioned below the van der Waals contact distance. This model is applied to recent experiments on the wild type (WT) and a double mutant (DM) of soybean lipoxygenase-1 (SLO). The compressive force necessary to prepare the tunneling-active distribution in WT SLO is found to fall in the ∼ nN range, which greatly exceeds the measured values of molecular motor and protein unfolding forces. This indicates that ∼60-100 MV/cm electric fields, aligned along the D-A bond axis, must be generated by an enzyme conformational interconversion that facilitates the PCET tunneling reaction. Based on the absolute value of the measured tunneling rate, and using previously calculated values of the electronic matrix element, the population of this tunneling-active conformation is found to lie in the range 10 -5 -10 -7 , indicating this is a rare structural fluctuation that falls well below the detection threshold of recent ENDOR experiments. Additional analysis of the DM tunneling kinetics leads to a proposal that a disordered (high entropy) conformation could be

  4. A missing piece of the puzzle in climate change hotspots: Near-surface turbulent interactions controlling ET-soil moisture coupling in semiarid areas

    Science.gov (United States)

    Haghighi, Erfan; Gianotti, Daniel J.; Rigden, Angela J.; Salvucci, Guido D.; Kirchner, James W.; Entekhabi, Dara

    2017-04-01

    Being located in the transitional zone between dry and wet climate areas, semiarid ecosystems (and their associated ecohydrological processes) play a critical role in controlling climate change and global warming. Land evapotranspiration (ET), which is a central process in the climate system and a nexus of the water, energy and carbon cycles, typically accounts for up to 95% of the water budget in semiarid areas. Thus, the manner in which ET is partitioned into soil evaporation and plant transpiration in these settings is of practical importance for water and carbon cycling and their feedbacks to the climate system. ET (and its partitioning) in these regions is primarily controlled by surface soil moisture which varies episodically under stochastic precipitation inputs. Important as the ET-soil moisture relationship is, it remains empirical, and physical mechanisms governing its nature and dynamics are underexplored. Thus, the objective of this study is twofold: (1) to provide observational evidence for the influence of surface cover conditions on ET-soil moisture coupling in semiarid regions using soil moisture data from NASA's SMAP satellite mission combined with independent observationally based ET estimates, and (2) to develop a relatively simple mechanistic modeling platform improving our physical understanding of interactions between micro and macroscale processes controlling ET and its partitioning in partially vegetated areas. To this end, we invoked concepts from recent progress in mechanistic modeling of turbulent energy flux exchange in bluff-rough regions, and developed a physically based ET model that explicitly accounts for how vegetation-induced turbulence in the near-surface region influences soil drying and thus ET rates and dynamics. Model predictions revealed nonlinearities in the strength of the ET-soil moisture relationship (i.e., ∂ET/∂θ) as vegetation cover fraction increases, accounted for by the nonlinearity of surface

  5. Neuronal Calcium Sensor-1 Binds the D2 Dopamine Receptor and G-protein-coupled Receptor Kinase 1 (GRK1) Peptides Using Different Modes of Interactions.

    Science.gov (United States)

    Pandalaneni, Sravan; Karuppiah, Vijaykumar; Saleem, Muhammad; Haynes, Lee P; Burgoyne, Robert D; Mayans, Olga; Derrick, Jeremy P; Lian, Lu-Yun

    2015-07-24

    Neuronal calcium sensor-1 (NCS-1) is the primordial member of the neuronal calcium sensor family of EF-hand Ca(2+)-binding proteins. It interacts with both the G-protein-coupled receptor (GPCR) dopamine D2 receptor (D2R), regulating its internalization and surface expression, and the cognate kinases GRK1 and GRK2. Determination of the crystal structures of Ca(2+)/NCS-1 alone and in complex with peptides derived from D2R and GRK1 reveals that the differential recognition is facilitated by the conformational flexibility of the C-lobe-binding site. We find that two copies of the D2R peptide bind within the hydrophobic crevice on Ca(2+)/NCS-1, but only one copy of the GRK1 peptide binds. The different binding modes are made possible by the C-lobe-binding site of NCS-1, which adopts alternative conformations in each complex. C-terminal residues Ser-178-Val-190 act in concert with the flexible EF3/EF4 loop region to effectively form different peptide-binding sites. In the Ca(2+)/NCS-1·D2R peptide complex, the C-terminal region adopts a 310 helix-turn-310 helix, whereas in the GRK1 peptide complex it forms an α-helix. Removal of Ser-178-Val-190 generated a C-terminal truncation mutant that formed a dimer, indicating that the NCS-1 C-terminal region prevents NCS-1 oligomerization. We propose that the flexible nature of the C-terminal region is essential to allow it to modulate its protein-binding sites and adapt its conformation to accommodate both ligands. This appears to be driven by the variability of the conformation of the C-lobe-binding site, which has ramifications for the target specificity and diversity of NCS-1. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. On the dynamics of the Mouth of the Columbia River: Results from a three-dimensional fully coupled wave-current interaction model

    Science.gov (United States)

    Akan, Çiǧdem; Moghimi, Saeed; Özkan-Haller, H. Tuba; Osborne, John; Kurapov, Alexander

    2017-07-01

    Numerical simulations were performed using a 3-D ocean circulation model (ROMS) two-way coupled to a phase-averaged wave propagation model (SWAN), to expand our understanding of the dynamics of wave-current interactions at the Mouth of the Columbia River (MCR). First, model results are compared with water elevations, currents, temperature, salinity, and wave measurements obtained by the U.S. Army Corp of Engineers during the Mega-Transect Experiment in 2005. We then discuss the effects of the currents on the waves and vice versa. Results show that wave heights are intensified notably at the entrance of the mouth in the presence of the tidal currents, especially in ebb flows. We also find nonlocal modifications to the wave field because of wave focusing processes that redirect wave energy toward the inlet mouth from adjacent areas, resulting in the presence of a tidal signatures in areas where local currents are weak. The model also suggests significant wave amplification at the edge of the expanding plume in the later stages of ebb, some tens of kilometers offshore of the inlet mouth, with potential implications for navigation safety. The effect of waves on the location of the plume is also analyzed, and results suggest that the plume is shifted in the down-wave direction when wave effects are considered, and that this shift is more pronounced for larger waves, and consistent with the presence of alongshore advection terms in the salt advection equation, which are related to the Stokes velocities associated with waves.

  7. Simulating groundwater-surface water interactions in the Canadian Prairies using a coupled land-atmosphere model (ParFlow-CLM)

    Science.gov (United States)

    Ali, M. A.; Ireson, A. M.; Keim, D.

    2015-12-01

    The Canadian prairies are cold and dry. Surface depressions are ubiquitous, and contain permanent or ephemeral ponds. The ponds are filled by snowmelt and precipitation on the ponds and lose a significant portion of their water to evaporation, but also, depending on their landscape position, may spill to other ponds or channels, recharge groundwater, or received groundwater discharge. Since precipitation and actual evaporation are closely balanced, the pond water balances are very sensitive to change in climate, and the prairies in general have been subject to damaging floods and droughts, in particular in the last decade or two. A 2.25 km2 field site at St Denis, central Saskatchewan, contains over 100 ponds, some permanent, some ephemeral, some saline, some fresh, some recharging groundwater, some receiving groundwater discharge. The site has been extensively studied for almost 50 years, with about one decade of continuous meteorological data, and three years of detailed pond level, soil moisture and temperature, and groundwater data. The objective of this study was to assess the performance of PARFLOW-CLM (a coupled land-atmosphere model) in simulating the pond-groundwater interactions at this site. Our conceptual model of the site includes soil properties that are progressively weathered with depth, and we implement this in a simplified dual permeability mathematical model of the soil hydraulic properties, whereby storage is dominated by the matrix and flow is dominated by macropores. The model performance was surprisingly good, doing quite a good job of capturing the observed groundwater and pond level dynamics. The soil freezing regime is also captured reasonably well, though the timing and pattern of the zero degree isotherm during soil thaw, which is critically important for runoff generation processes, was not captured as well. The model provides credible insights into the spatial patterns of evapotranspiration, and the seasonal dynamics of subsurface

  8. An investigation of sodium–CO{sub 2} interaction byproduct cleaning agent for SFR coupled with S-CO{sub 2} Brayton cycle

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Hwa-Young, E-mail: jhy0523@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Division of SFR NSSS System Design, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Lee, Jeong Ik, E-mail: jeongiklee@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Wi, Myung-Hwan, E-mail: mhwi@kaeri.re.kr [Division of SFR NSSS System Design, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Ahn, Hong Joo, E-mail: ahjoo@kaeri.re.kr [Division of Nuclear Chemistry Research, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

    2016-02-15

    Highlights: • Study on cleaning agent was conducted to remove Na–CO{sub 2} interaction byproducts. • Screening criteria to select candidate substances as cleaning agents were suggested. • The mixtures of Na{sub 2}CO{sub 3} with NaBrO{sub 3}, NaClO{sub 3}, or NaBF{sub 4} were thermally analyzed with the TG/DTA studies. • Three candidate substances decomposed before 600 °C and did not react with Na{sub 2}CO{sub 3}. - Abstract: One of the promising future nuclear energy systems, the Sodium-cooled Fast Reactor (SFR) has been actively developed internationally. Recently, to improve safety and economics of a SFR further, coupling supercritical CO{sub 2} power cycle was suggested. However, there can be a chemical reaction between sodium and CO{sub 2} at high temperature (more than 400 °C) when the pressure boundary fails in a sodium–CO{sub 2} heat exchanger. To ensure the performance of such a system, it is important to employ a cleaning agent to recover the system back to normal condition after the reaction. When sodium and CO{sub 2} react, solid and gaseous reaction products such as sodium carbonate (Na{sub 2}CO{sub 3}) and carbon monoxide (CO) appear. Since most of solid reaction products are hard and can deteriorate system performance, quick removal of solid reaction products becomes very important for economic performance of the system. Thus, the authors propose the conceptual method to remove the byproducts with a chemical reaction at high temperature. The chemical reaction will take place between the reaction byproducts and a cleaning agent while the cleaning agent is inert with sodium. Thus, various sodium-based compounds were first investigated and three candidate substances satisfying several criteria were selected; sodium bromate (NaBrO{sub 3}), sodium chlorate (NaClO{sub 3}), and sodium tetrafluoroborate (NaBF{sub 4}). The selected substances were thermally analyzed with the TG/DTA studies. Unfortunately, it was revealed that all candidate

  9. A HPC “Cyber Wind Facility” Incorporating Fully-Coupled CFD/CSD for Turbine-Platform-Wake Interactions with the Atmosphere and Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Brasseur, James G. [Univ. of Colorado, Boulder, CO (United States)

    2017-05-09

    The central aims of the DOE-supported “Cyber Wind Facility” project center on the recognition that wind turbines over land and ocean generate power from atmospheric winds that are inherently turbulent and strongly varying, both spatially over the rotor disk and in temporally as the rotating blades pass through atmospheric eddies embedded within the mean wind. The daytime unstable atmospheric boundary layer (ABL) is particularly variable in space time as solar heating generates buoyancy-driven motions that interact with strong mean shear in the ABL “surface layer,” the lowest 200 - 300 m where wind turbines reside in farms. With the “Cyber Wind Facility” (CWF) program we initiate a research and technology direction in which “cyber data” are generated from “computational experiments” within a “facility” akin to a wind tunnel, but with true space-time atmospheric turbulence that drive utility-scale wind turbines at full-scale Reynolds numbers. With DOE support we generated the key “modules” within a computational framework to create a first generation Cyber Wind Facility (CWF) for single wind turbines in the daytime ABL---both over land where the ABL globally unstable and over water with closer-to-neutral atmospheric conditions but with time response strongly affected by wave-induced forcing of the wind turbine platform (here a buoy configuration). The CWF program has significantly improved the accuracy of actuator line models, evaluated with the Cyber Wind Facility in full blade-boundary-layer-resolved mode. The application of the CWF made in this program showed the existence of important ramp-like response events that likely contribute to bearing fatigue failure on the main shaft and that the advanced ALM method developed here captures the primary nonsteady response characteristics. Long-time analysis uncovered distinctive key dynamics that explain primary mechanisms that underlie potentially deleterious load transients. We also showed

  10. Gestural coupling and social cognition

    DEFF Research Database (Denmark)

    Michael, John; Krueger, Joel William

    2012-01-01

    Social cognition researchers have become increasingly interested in the ways that behavioral, physiological, and neural coupling facilitate social interaction and interpersonal understanding. We distinguish two ways of conceptualizing the role of such coupling processes in social cognition: strong...... an essential enabling feature for social interaction and interpersonal understanding more generally and thus ought to exhibit severe deficits in these areas. We challenge SI's prediction and show how MS cases offer compelling reasons for instead adopting MI's pluralistic model of social interaction...... and interpersonal understanding. We conclude that investigations of coupling processes within social interaction should inform rather than marginalize or eliminate investigation of higher-level individual cognition...

  11. Tuning the competition between ferromagnetism and antiferromagnetism in a half-doped manganite through magnetoelectric coupling

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Di [University of California; Liu, Jian [University of California, Berkeley & LBNL; Okamoto, Satoshi [ORNL; Jagannatha, Suresha [Lawrence Berkeley National Laboratory (LBNL); Chen, Yi-Chun [National Cheng Kung University, Tainan, Taiwan; Yu, Pu [Tsinghua University; Chu, Ying-Hao [National Chiao Tung University, Hsinchu, Taiwan; Arenholz, Elke [Lawrence Berkeley National Laboratory (LBNL); Ramesh, Ramamoorthy [University of California, Berkeley

    2013-01-01

    We investigate the possibility of controlling the magnetic phase transition of the heterointerface between a half-doped manganite La0:5Ca0:5MnO3 and a multiferroic BiFeO3 (BFO) through magnetoelectric coupling. Using macroscopic magnetometry and element-selective x-ray magnetic circular dichroism at the Mn and Fe L edges, we discover that the ferroelectric polarization of BFO controls simultaneously the magnetization of BFO and La0.5Ca0.5MnO3 (LCMO). X-ray absorption spectra at the oxygen K edge and linear dichroism at the Mn L edge suggest that the interfacial coupling is mainly derived from the superexchange between Mn and Fe t2g spins. The combination of x-ray absorption spectroscopy and mean-field theory calculations reveals that the d-electron modulation of Mn cations changes the magnetic coupling in LCMO, which controls the enhanced canted moments of interfacial BFO via the interfacial coupling. Our results demonstrate that the competition between ferromagnetic and antiferromagnetic instability can be modulated by an electric field at the heterointerface, providing another pathway for the electrical field control of magnetism.

  12. Modeling of Structural-Acoustic Interaction Using Coupled FE/BE Method and Control of Interior Acoustic Pressure Using Piezoelectric Actuators

    Science.gov (United States)

    Mei, Chuh; Shi, Yacheng

    1997-01-01

    A coupled finite element (FE) and boundary element (BE) approach is presented to model full coupled structural/acoustic/piezoelectric systems. The dual reciprocity boundary element method is used so that the natural frequencies and mode shapes of the coupled system can be obtained, and to extend this approach to time dependent problems. The boundary element method is applied to interior acoustic domains, and the results are very accurate when compared with limited exact solutions. Structural-acoustic problems are then analyzed with the coupled finite element/boundary element method, where the finite element method models the structural domain and the boundary element method models the acoustic domain. Results for a system consisting of an isotropic panel and a cubic cavity are in good agreement with exact solutions and experiment data. The response of a composite panel backed cavity is then obtained. The results show that the mass and stiffness of piezoelectric layers have to be considered. The coupled finite element and boundary element equations are transformed into modal coordinates, which is more convenient for transient excitation. Several transient problems are solved based on this formulation. Two control designs, a linear quadratic regulator (LQR) and a feedforward controller, are applied to reduce the acoustic pressure inside the cavity based on the equations in modal coordinates. The results indicate that both controllers can reduce the interior acoustic pressure and the plate deflection.

  13. Entrepreneurial Couples

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Van Praag, Mirjam; Thompson, Peter

    2015-01-01

    We study possible motivations for co-entreprenurial couples to start up a joint firm, using a sample of 1,069 Danish couples that established a joint enterprise between 2001 and 2010. We compare their pre-entry characteristics, firm performance and post-dissolution private and financial outcomes...

  14. A highly conserved glycine within linker I and the extreme C terminus of G protein alpha subunits interact cooperatively in switching G protein-coupled receptor-to-effector specificity

    DEFF Research Database (Denmark)

    Kostenis, Evi; Martini, Lene; Ellis, James

    2004-01-01

    Numerous studies have attested to the importance of the extreme C terminus of G protein alpha subunits in determining their selectivity of receptor recognition. We have previously reported that a highly conserved glycine residue within linker I is important for constraining the fidelity of receptor...... recognition by Galpha(q) proteins. Herein, we explored whether both modules (linker I and extreme C terminus) interact cooperatively in switching G protein-coupled receptor (GPCR)-to-effector specificity and created as models mutant Galpha(q) proteins in which glycine was replaced with various amino acids...... and the C-terminal five Galpha(q) residues with the corresponding Galpha(i) or Galpha(s) sequence. Coupling properties of the mutated Galpha(q) proteins were determined after coexpression with a panel of 13 G(i)-and G(s) -selective receptors and compared with those of Galpha proteins modified in only one...

  15. Coupling in the Tevatron

    International Nuclear Information System (INIS)

    Gelfand, N.M.

    1994-12-01

    The performance of the Fermilab Tevatron Collider at the commencement of run Ib was far below expectations. After a frustrating period of several months, a low-β quad downstream of the interaction point at B0 was found to be rolled. This rolled quadrupole coupled the horizontal and vertical motion of the Tevatron beams. It also made matching the beam from the Main Ring to the Tevatron impossible, resulting in emittance blow up on injection. The net result of the roll was a significant reduction in the Tevatron luminosity. When the roll in the quadrupole was corrected the performance of the Tevatron improved dramatically. This note will discuss the experimental data indicating the presence of coupling and subsequent calculations which show how coupling an affect the luminosity. It is not intended to exhaust a discussion of coupling, which hopefully will be understood well enough to be discussed in a subsequent note

  16. Electronic Mechanisms of Intra and Intermolecular J Couplings in Systems with C-H···O Interactions

    Directory of Open Access Journals (Sweden)

    Claudio N. Cavasotto

    2003-04-01

    Full Text Available Abstract: Correlation effects on the change of 1J(CH couplings in model systems I:NCH...H2O and II:CH4...H2O as a function of the H...O distance are discussed. RPA and SOPPA results follow a similar trend in system II. In system I RPA values decrease monotonously as the H...O distance decreases, while SOPPA ones exhibit flat maximum near equilibrium. Such different behavior is ascribed to the π-transmitted component. Intermolecular couplings at the equilibrium geometry of I are analyzed by means of the CLOPPA approach. The larger absolute value of 2hJ(CO compared to 1hJ(HO is found to arise from contributions involving a vacant LMO localized in the C-H...O moiety.

  17. First-order exchange coefficient coupling for simulating surface water-groundwater interactions: Parameter sensitivity and consistency with a physics-based approach

    Science.gov (United States)

    Ebel, B.A.; Mirus, B.B.; Heppner, C.S.; VanderKwaak, J.E.; Loague, K.

    2009-01-01

    Distributed hydrologic models capable of simulating fully-coupled surface water and groundwater flow are increasingly used to examine problems in the hydrologic sciences. Several techniques are currently available to couple the surface and subsurface; the two most frequently employed approaches are first-order exchange coefficients (a.k.a., the surface conductance method) and enforced continuity of pressure and flux at the surface-subsurface boundary condition. The effort reported here examines the parameter sensitivity of simulated hydrologic response for the first-order exchange coefficients at a well-characterized field site using the fully coupled Integrated Hydrology Model (InHM). This investigation demonstrates that the first-order exchange coefficients can be selected such that the simulated hydrologic response is insensitive to the parameter choice, while simulation time is considerably reduced. Alternatively, the ability to choose a first-order exchange coefficient that intentionally decouples the surface and subsurface facilitates concept-development simulations to examine real-world situations where the surface-subsurface exchange is impaired. While the parameters comprising the first-order exchange coefficient cannot be directly estimated or measured, the insensitivity of the simulated flow system to these parameters (when chosen appropriately) combined with the ability to mimic actual physical processes suggests that the first-order exchange coefficient approach can be consistent with a physics-based framework. Copyright ?? 2009 John Wiley & Sons, Ltd.

  18. The effect of higher order different meson exchange nucleon-nucleon interactions on the three-nucleon binding energy coupling problem

    International Nuclear Information System (INIS)

    Osman, A.; Ramadan, S.

    1989-01-01

    Faddeev equations of bound three-nucleon system are presented as a set of integral equations. To solve them, a sutable form of the nucleon-nucleon interactions is used: with the exchange of a scalar meson, a pseudoscalar meson and a massless vector meson. Higher orders of these different meson exchanges in the nucleon-nucleon interactions have been taken into account. With these nuclear forces and nucleon-nucleon interactions, the three-nucleon binding energy is calculated by solving the Faddeev integral equations. The obtained value of the three-nucleon binding energy is 8.441 MeV. The inclusion of the higher order terms of the different meson exchange in the nuclear nucleon-nucleon interaction is found to affect the three-nucleon binding by about 3.92%. 3 figs., 16 refs

  19. Single-step electron transfer on the nanometer scale: ultra-fast charge shift in strongly coupled zinc porphyrin-gold porphyrin dyads.

    Science.gov (United States)

    Fortage, Jérôme; Boixel, Julien; Blart, Errol; Hammarström, Leif; Becker, Hans Christian; Odobel, Fabrice

    2008-01-01

    The synthesis, electrochemical properties, and photoinduced electron transfer processes of a series of three novel zinc(II)-gold(III) bisporphyrin dyads (ZnP--S--AuP(+)) are described. The systems studied consist of two trisaryl porphyrins connected directly in the meso position via an alkyne unit to tert-(phenylenethynylene) or penta(phenylenethynylene) spacers. In these dyads, the estimated center to center interporphyrin separation distance varies from 32 to 45 A. The absorption, emission, and electrochemical data indicate that there are strong electronic interactions between the linked elements, thanks to the direct attachment of the spacer on the porphyrin ring through the alkyne unit. At room temperature in toluene, light excitation of the zinc porphyrin results in almost quantitative formation of the charge shifted state (.+)ZnP--S--AuP(.), whose lifetime is in the order of hundreds of picoseconds. In this solvent, the charge-separated state decays to the ground state through the intermediate population of the zinc porphyrin triplet excited state. Excitation of the gold porphyrin leads instead to rapid energy transfer to the triplet ZnP. In dichloromethane the charge shift reactions are even faster, with time constants down to 2 ps, and may be induced also by excitation of the gold porphyrin. In this latter solvent, the longest charge-shifted lifetime (tau=2.3 ns) was obtained with the penta-(phenylenethynylene) spacer. The charge shift reactions are discussed in terms of bridge-mediated super-exchange mechanisms as electron or hole transfer. These new bis-porphyrin arrays, with strong electronic coupling, represent interesting molecular systems in which extremely fast and efficient long-range photoinduced charge shift occurs over a long distance. The rate constants are two to three orders of magnitude larger than for corresponding ZnP--AuP(+) dyads linked via meso-phenyl groups to oligo-phenyleneethynylene spacers. This study demonstrates the critical

  20. Entrepreneurial Couples

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Van Praag, Mirjam; Thompson, Peter

    with a selected set of comparable firms and couples. We find evidence that couples often establish a business together because one spouse – most commonly the female – has limited outside opportunities in the labor market. However, the financial benefits for each of the spouses, and especially the female......We study possible motivations for co-entrepenurial couples to start up a joint firm, using a sample of 1,069 Danish couples that established a joint enterprise between 2001 and 2010. We compare their pre-entry characteristics, firm performance and postdissolution private and financial outcomes......, are larger in co-entrepreneurial firms, both during the life of the business and post-dissolution. The start-up of co-entrepreneurial firms seems therefore a sound investment in the human capital of both spouses as well as in the reduction of income inequality in the household. We find no evidence of non...

  1. Entrepreneurial Couples

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Van Praag, Mirjam; Thompson, Peter

    with a selected set of comparable firms and couples. We find evidence that couples often establish a business together because one spouse - most commonly the female - has limited outside opportunities in the labor market. However, the financial benefits for each of the spouses, and especially the female......We study possible motivations for co-entrepenurial couples to start up a joint firm, us-ing a sample of 1,069 Danish couples that established a joint enterprise between 2001 and 2010. We compare their pre-entry characteristics, firm performance and post-dissolution private and financial outcomes......, are larger in co-entrepreneurial firms, both during the life of the business and post-dissolution. The start-up of co-entrepreneurial firms seems therefore a sound in-vestment in the human capital of both spouses as well as in the reduction of income inequality in the household. We find no evidence of non...

  2. Computational fluid dynamics and frequency-dependent finite-difference time-domain method coupling for the interaction between microwaves and plasma in rocket plumes

    International Nuclear Information System (INIS)

    Kinefuchi, K.; Funaki, I.; Shimada, T.; Abe, T.

    2012-01-01

    Under certain conditions during rocket flights, ionized exhaust plumes from solid rocket motors may interfere with radio frequency transmissions. To understand the relevant physical processes involved in this phenomenon and establish a prediction process for in-flight attenuation levels, we attempted to measure microwave attenuation caused by rocket exhaust plumes in a sea-level static firing test for a full-scale solid propellant rocket motor. The microwave attenuation level was calculated by a coupling simulation of the inviscid-frozen-flow computational fluid dynamics of an exhaust plume and detailed analysis of microwave transmissions by applying a frequency-dependent finite-difference time-domain method with the Drude dispersion model. The calculated microwave attenuation level agreed well with the experimental results, except in the case of interference downstream the Mach disk in the exhaust plume. It was concluded that the coupling estimation method based on the physics of the frozen plasma flow with Drude dispersion would be suitable for actual flight conditions, although the mixing and afterburning in the plume should be considered depending on the flow condition.

  3. Computational fluid dynamics and frequency-dependent finite-difference time-domain method coupling for the interaction between microwaves and plasma in rocket plumes

    Energy Technology Data Exchange (ETDEWEB)

    Kinefuchi, K. [Department of Aeronautics and Astronautics, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Funaki, I.; Shimada, T.; Abe, T. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)

    2012-10-15

    Under certain conditions during rocket flights, ionized exhaust plumes from solid rocket motors may interfere with radio frequency transmissions. To understand the relevant physical processes involved in this phenomenon and establish a prediction process for in-flight attenuation levels, we attempted to measure microwave attenuation caused by rocket exhaust plumes in a sea-level static firing test for a full-scale solid propellant rocket motor. The microwave attenuation level was calculated by a coupling simulation of the inviscid-frozen-flow computational fluid dynamics of an exhaust plume and detailed analysis of microwave transmissions by applying a frequency-dependent finite-difference time-domain method with the Drude dispersion model. The calculated microwave attenuation level agreed well with the experimental results, except in the case of interference downstream the Mach disk in the exhaust plume. It was concluded that the coupling estimation method based on the physics of the frozen plasma flow with Drude dispersion would be suitable for actual flight conditions, although the mixing and afterburning in the plume should be considered depending on the flow condition.

  4. Coupled moderator neutronics

    International Nuclear Information System (INIS)

    Russell, G.J.; Pitcher, E.J.; Ferguson, P.D.

    1995-01-01

    Optimizing the neutronic performance of a coupled-moderator system for a Long-Pulse Spallation Source is a new and challenging area for the spallation target-system designer. For optimal performance of a neutron source, it is essential to have good communication with instrument scientists to obtain proper design criteria and continued interaction with mechanical, thermal-hydraulic, and materials engineers to attain a practical design. A good comprehension of the basics of coupled-moderator neutronics will aid in the proper design of a target system for a Long-Pulse Spallation Source

  5. The importance of the on-site electron-electron interaction for the magnetic coupling in the zigzag spin-chain compound In2VO5

    KAUST Repository

    Wang, Hao; Schwingenschlö gl, Udo

    2010-01-01

    We present first-principles electronic structure calculations for the zigzag spin-chain compound In2VO5 using the generalized gradient approximation both with and without inclusion of an on-site Coulomb interaction. It has been proposed that In2VO5

  6. Characterization of the interaction layer in diffusion couples U-Mo-Zr/Al and U-Mo-Zr/Al-A356 at 550 C degrees

    International Nuclear Information System (INIS)

    Komar Varela, Carolina; Arico, Sergio; Mirandou, Marcela; Balart, Silvia; Gribaudo, Luis

    2007-01-01

    Out-of-pile diffusion experiments were performed between U-7 wt.% Mo-1 wt.% Zr and Al or Al A356 (7,1 wt.% Si) at 550 C degrees. In this work morphological characterization and phase identification on both interaction layers are presented. They were carried out by the use of different techniques: optical and scanning electron microscopy, X-ray diffraction and WDS microanalysis. In the interaction layer U-7 wt.% Mo-1 wt.% Zr/Al, the phases UAl 3 , UAl 4 , Al 20 Mo 2 U and Al 43 Mo 4 U 6 were identified. Similar results in the interaction layer of the U-7 % Mo/Al at 580 C degrees were previously obtained. In the interaction layer U-7 wt.% Mo-1 wt.% Zr/Al A356, the phases U(Al,Si) 3 with 25 at.% Si and Si 5 U 3 were identified. This last phase, with a higher Si concentration, was identified with X-ray diffraction synchrotron radiation performed at the National Synchrotron Light Laboratory, Campinas, Brazil. (author) [es

  7. Structural basis of G protein-coupled receptor-Gi protein interaction: formation of the cannabinoid CB2 receptor-Gi protein complex.

    Science.gov (United States)

    Mnpotra, Jagjeet S; Qiao, Zhuanhong; Cai, Jian; Lynch, Diane L; Grossfield, Alan; Leioatts, Nicholas; Hurst, Dow P; Pitman, Michael C; Song, Zhao-Hui; Reggio, Patricia H

    2014-07-18

    In this study, we applied a comprehensive G protein-coupled receptor-Gαi protein chemical cross-linking strategy to map the cannabinoid receptor subtype 2 (CB2)-Gαi interface and then used molecular dynamics simulations to explore the dynamics of complex formation. Three cross-link sites were identified using LC-MS/MS and electrospray ionization-MS/MS as follows: 1) a sulfhydryl cross-link between C3.53(134) in TMH3 and the Gαi C-terminal i-3 residue Cys-351; 2) a lysine cross-link between K6.35(245) in TMH6 and the Gαi C-terminal i-5 residue, Lys-349; and 3) a lysine cross-link between K5.64(215) in TMH5 and the Gαi α4β6 loop residue, Lys-317. To investigate the dynamics and nature of the conformational changes involved in CB2·Gi complex formation, we carried out microsecond-time scale molecular dynamics simulations of the CB2 R*·Gαi1β1γ2 complex embedded in a 1-palmitoyl-2-oleoyl-phosphatidylcholine bilayer, using cross-linking information as validation. Our results show that although molecular dynamics simulations started with the G protein orientation in the β2-AR*·Gαsβ1γ2 complex crystal structure, the Gαi1β1γ2 protein reoriented itself within 300 ns. Two major changes occurred as follows. 1) The Gαi1 α5 helix tilt changed due to the outward movement of TMH5 in CB2 R*. 2) A 25° clockwise rotation of Gαi1β1γ2 underneath CB2 R* occurred, with rotation ceasing when Pro-139 (IC-2 loop) anchors in a hydrophobic pocket on Gαi1 (Val-34, Leu-194, Phe-196, Phe-336, Thr-340, Ile-343, and Ile-344). In this complex, all three experimentally identified cross-links can occur. These findings should be relevant for other class A G protein-coupled receptors that couple to Gi proteins. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. A numerical study of the effect of irrigation on land-atmosphere interactions in a spring wheat cropland in India using a coupled atmosphere-crop growth dynamics model

    Science.gov (United States)

    Kumari, S.; Sharma, P.; Srivastava, A.; Rastogi, D.; Sehgal, V. K.; Dhakar, R.; Roy, S. B.

    2017-12-01

    Vegetation dynamics and surface meteorology are tightly coupled through the exchange of momentum, moisture and heat between the land surface and the atmosphere. In this study, we use a recently developed coupled atmosphere-crop growth dynamics model to study these exchanges and their effects in a spring wheat cropland in northern India. In particular, we investigate the role of irrigation in controlling crop growth rates, surface meteorology, and sensible and latent heat fluxes. The model is developed by implementing a crop growth module based on the Simple and Universal Crop growth Simulator (SUCROS) model in the Weather Research Forecasting (WRF) mesoscale atmospheric model. The crop module calculates photosynthesis rates, carbon assimilation, and biomass partitioning as a function of environmental factors and crop development stage. The leaf area index (LAI) and root depth calculated by the crop module is then fed to the Noah-MP land module of WRF to calculate land-atmosphere fluxes. The crop model is calibrated using data from an experimental spring wheat crop site in the Indian Agriculture Research Institute. The coupled model is capable of simulating the observed spring wheat phenology. Irrigation is simulated by changing the soil moisture levels from 50% - 100% of field capacity. Results show that the yield first increases with increasing soil moisture and then starts decreasing as we further increase the soil moisture. Yield attains its maximum value with soil moisture at the level of 60% water of FC. At this level, high LAI values lead to a decrease in the Bowen Ratio because more energy is transferred to the atmosphere as latent heat rather than sensible heat resulting in a cooling effect on near-surface air temperatures. Apart from improving simulation of land-atmosphere interactions, this coupled modeling approach can form the basis for the seamless crop yield and seasonal scale weather outlook prediction system.

  9. How strong is the strong interaction? The πNN coupling constant and the shape and normalization of np scattering cross sections

    International Nuclear Information System (INIS)

    Blomgren, J.; Olsson, N.; Rahm, J.

    2000-01-01

    The world data base on np scattering differential cross section data from 100 to 1000 MeV incident neutron energy has been reviewed. In addition, the status of the np total cross section and the pp → dπ + total cross section is discussed, as these have frequently been used to normalize np scattering data. It appears that the shapes of the largest np data sets tend to fall into two groups, with different steepness at backward angles. Also, it seems as the two major techniques for normalizing data yield incompatible results. Both these effects have consequences when using np data to determine the pion-nucleon coupling constant, g 2 πNN , which is currently under debate. (orig.)

  10. Ultrafast switching of the magnetic ground state in d1 titanates though nonlinear phononic coupling

    Science.gov (United States)

    Gu, Mingqiang; Rondinelli, James M.

    LaTiO3 and YTiO3 are isostructure d1 titanates, which exhibit distinct magnetic and orbital properties: The former is a G-type antiferromagnet with a 150 K Neel temperature whereas the latter is a rare ferromagnetic (FM) insulator with a 30 K Curie temperature. With first-principles density functional theory calculations, we identify the local structural origin of the magnetic order difference in these orthorhombic perovskites. By increasing the tilt and rotation angles in LaTiO3, respectively, LaTiO3 is predicted to undergo a magnetic phase transition to an FM state. Similarly, decreasing the tilt and rotation angles in YTiO3 leads to a FM-to-AFM phase transition. The underlying physics is attributed to the change in the superexchange coupling between Ti-sites. Last, we propose a route to switch the magnetism in the titanates by controlling the octahedral distortions through dynamical nonlinear phononic coupling. The proposed experiment requires the use of static strain to position the crystal structure in proximity to the structural transition combined with readily achievable fluencies in an ultrafast optical pump-probe geometry The theory work is supported by the U.S Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-SC0012375.

  11. 100 Years of Superconductivity: The Past, The Present And The ...

    African Journals Online (AJOL)

    ... of spinning particles leading to a Hulthen potential that is attractive between two electrons in singlet couplings while at large distance the CPF is by superexchange interaction which is purely a quantum mechanical effect. Journal of the Nigerian Association of Mathematical Physics, Volume 19 (November, 2011), pp 623 – ...

  12. The importance of the on-site electron-electron interaction for the magnetic coupling in the zigzag spin-chain compound In2VO5

    KAUST Repository

    Wang, Hao

    2010-09-27

    We present first-principles electronic structure calculations for the zigzag spin-chain compound In2VO5 using the generalized gradient approximation both with and without inclusion of an on-site Coulomb interaction. It has been proposed that In2VO5 is characterized by itinerant V 3d electrons at high temperature and localized electrons at low temperature. Consequently, it is to be expected that electronic correlations play an important role for the magnetic transition from ferromagnetic to antiferromagnetic exchange around 120 K. In this context, we study the electronic and magnetic properties of a set of possible spin configurations. Our calculations show that inclusion of an on-site Coulomb interaction in fact changes the ground state from ferromagnetic to antiferromagnetic. © 2010 IOP Publishing Ltd.

  13. On the existence of weak solution to the coupled fluid-structure interaction problem for non-Newtonian shear-dependent fluid

    Czech Academy of Sciences Publication Activity Database

    Hundertmark-Zaušková, A.; Lukáčová-Medviďová, M.; Nečasová, Šárka

    2016-01-01

    Roč. 68, č. 1 (2016), s. 193-243 ISSN 0025-5645 R&D Projects: GA ČR(CZ) GAP201/11/1304 Institutional support: RVO:67985840 Keywords : non-Newtonian fluids * fluid-structure interaction * shear-thinning fluids Subject RIV: BA - General Mathematics Impact factor: 0.592, year: 2016 http://projecteuclid.org/euclid.jmsj/1453731541

  14. Independent components analysis coupled with 3D-front-face fluorescence spectroscopy to study the interaction between plastic food packaging and olive oil.

    Science.gov (United States)

    Kassouf, Amine; El Rakwe, Maria; Chebib, Hanna; Ducruet, Violette; Rutledge, Douglas N; Maalouly, Jacqueline

    2014-08-11

    Olive oil is one of the most valued sources of fats in the Mediterranean diet. Its storage was generally done using glass or metallic packaging materials. Nowadays, plastic packaging has gained worldwide spread for the storage of olive oil. However, plastics are not inert and interaction phenomena may occur between packaging materials and olive oil. In this study, extra virgin olive oil samples were submitted to accelerated interaction conditions, in contact with polypropylene (PP) and polylactide (PLA) plastic packaging materials. 3D-front-face fluorescence spectroscopy, being a simple, fast and non destructive analytical technique, was used to study this interaction. Independent components analysis (ICA) was used to analyze raw 3D-front-face fluorescence spectra of olive oil. ICA was able to highlight a probable effect of a migration of substances with antioxidant activity. The signals extracted by ICA corresponded to natural olive oil fluorophores (tocopherols and polyphenols) as well as newly formed ones which were tentatively identified as fluorescent oxidation products. Based on the extracted fluorescent signals, olive oil in contact with plastics had slower aging rates in comparison with reference oils. Peroxide and free acidity values validated the results obtained by ICA, related to olive oil oxidation rates. Sorbed olive oil in plastic was also quantified given that this sorption could induce a swelling of the polymer thus promoting migration. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Kinetic study of hydrogen-material interactions in nickel base alloy 600 and stainless steel 316L through coupled experimental and numerical analysis

    International Nuclear Information System (INIS)

    Hurley, Caitlin-Mae

    2015-01-01

    In France all of the nuclear power plant facilities in service today are pressurized water reactors (PWR). Some parts of the PWR in contact with the primary circuit medium, such as the steam generator tubes (fabricated in nickel base alloy A600) and some reactor core internal components (fabricated in stainless steel 316L), can fall victim to environmental degradation phenomena such as stress corrosion cracking (SCC). In the late 1950's, H. Coriou observed experimentally and predicted this type of cracking in alloys traditionally renowned for their SCC resistance (A600). Just some 20 to 30 years later his predictions became a reality. Since then, numerous studies have focused on the description and comprehension of the SCC phenomenon in primary water under reactor operating conditions. In view of reactor lifetime extension, it has become both critical and strategic to be capable of simulating SCC phenomenon in order to optimize construction materials, operating conditions, etc. and to understand the critical parameters in order to limit the damage done by SCC. This study focuses on the role hydrogen plays in SCC phenomenon and in particular H-material interactions. Hydrogen, from primary medium in the form of dissolved H gas or H from the water, can be absorbed by the alloy during the oxidation process taking place under reactor operating conditions. Once absorbed, hydrogen may be transported across the material, diffusing in the interstitial sites of the crystallographic structure and interacting with local defects, such as dislocations, precipitates, vacancies, etc. The presence of these [local defect] sites can slow the hydrogen transport and may provoke local H accumulation in the alloy. This accumulation could modify the local mechanical properties of the material and favor premature rupture. It is therefore essential to identify the nature of these H-material interactions, specifically the rate of H diffusion and hydrogen trapping kinetics at these

  16. Improved Transient Performance of a Fuzzy Modified Model Reference Adaptive Controller for an Interacting Coupled Tank System Using Real-Coded Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Asan Mohideen Khansadurai

    2014-01-01

    Full Text Available The main objective of the paper is to design a model reference adaptive controller (MRAC with improved transient performance. A modification to the standard direct MRAC called fuzzy modified MRAC (FMRAC is used in the paper. The FMRAC uses a proportional control based Mamdani-type fuzzy logic controller (MFLC to improve the transient performance of a direct MRAC. The paper proposes the application of real-coded genetic algorithm (RGA to tune the membership function parameters of the proposed FMRAC offline so that the transient performance of the FMRAC is improved further. In this study, a GA based modified MRAC (GAMMRAC, an FMRAC, and a GA based FMRAC (GAFMRAC are designed for a coupled tank setup in a hybrid tank process and their transient performances are compared. The results show that the proposed GAFMRAC gives a better transient performance than the GAMMRAC or the FMRAC. It is concluded that the proposed controller can be used to obtain very good transient performance for the control of nonlinear processes.

  17. Primary processes of the electron-protic species coupling in pure aqueous phases: - femtosecond laser spectroscopy study; - quantum approach of the electron-water interaction

    International Nuclear Information System (INIS)

    Pommeret, Stanislas

    1991-01-01

    This thesis work deals with the coupling mechanisms between an electron, water molecules or protic species (hydronium ion, hydroxyl radical). Two complementary studies have been carry out in pure aqueous phases. The first one is concerned with the structural aspect of the hydrated electron which is studied via a semi-quantum approach Splitting Operator Method. The results indicates the importance of the second hydration shell in the localisation of an electron at 77 and 300 Kelvin. The second part of this work relates to the dynamic of the primary processes in light or heavy water at room temperature: the ion-molecule reaction, radical pair formation, geminate recombination of the hydrated electron with the hydronium ion and the hydroxyl radical. The dynamic of these reactions is studied by time resolved absorption spectroscopy from the near infrared to the near ultraviolet with a few tens femto-seconds temporal precision. The analysis of the primary processes takes into account the protic properties of water molecules. (author) [fr

  18. Study on water-sediment interaction in samples from Rio das Velhas - Minas Gerais State - Brazil using instrumental neutron activation analysis, and argon plasma coupled mass spectroscopy

    International Nuclear Information System (INIS)

    Veado, Maria Adelaide R.V.; Oliveira, Arno H. de; Revel, G.; Pinte, G.; Toulhoat, P.

    1999-01-01

    Sorption of the metallic elements in aqueous solutions in surface of the hydroxides affects the transport of heavy elements in the freshwaters. Sorption and the chemistry of the hydroxides are important studies for knowledge in geology, waters and waste treatment, and environment studies. In the industrial mining region areas, the river surface waters are subject to modifications in its physical and chemistries properties: pH, DBO, conductivity and alkalinity. Instrumental neutron activation analysis and inductively coupled plasma-mass spectrometry (ICP-MS), have ben used for the determination of toxic heavy metals and others pollutants in the Das Velhas river in State of Minas Gerais, in south-east Brazil. Water samples were collected with acidification on site, which provoked a change of its natural pH. Consequently, metallic elements associated to hydroxides and to particles in suspension were liberated. The objective of this paper is to show the different behavior of any elements, in water of Das Velhas river, with relation of its chemical forms (cations or anions), the solubility degree, the pH and the presence of rare earth elements. (author)

  19. Using the Model Coupling Toolkit to couple earth system models

    Science.gov (United States)

    Warner, J.C.; Perlin, N.; Skyllingstad, E.D.

    2008-01-01

    Continued advances in computational resources are providing the opportunity to operate more sophisticated numerical models. Additionally, there is an increasing demand for multidisciplinary studies that include interactions between different physical processes. Therefore there is a strong desire to develop coupled modeling systems that utilize existing models and allow efficient data exchange and model control. The basic system would entail model "1" running on "M" processors and model "2" running on "N" processors, with efficient exchange of model fields at predetermined synchronization intervals. Here we demonstrate two coupled systems: the coupling of the ocean circulation model Regional Ocean Modeling System (ROMS) to the surface wave model Simulating WAves Nearshore (SWAN), and the coupling of ROMS to the atmospheric model Coupled Ocean Atmosphere Prediction System (COAMPS). Both coupled systems use the Model Coupling Toolkit (MCT) as a mechanism for operation control and inter-model distributed memory transfer of model variables. In this paper we describe requirements and other options for model coupling, explain the MCT library, ROMS, SWAN and COAMPS models, methods for grid decomposition and sparse matrix interpolation, and provide an example from each coupled system. Methods presented in this paper are clearly applicable for coupling of other types of models. ?? 2008 Elsevier Ltd. All rights reserved.

  20. Study of the interactions between the transuranic elements and some environmental ligands by the hyphenated technique capillary electrophoresis: inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Topin, S.

    2009-09-01

    In this work, the capabilities of the hyphenated Capillary Electrophoresis-ICP-MS technique are used to improve the knowledge on the transuranic element speciation in the environment (nuclear waste management) and in the framework of spent fuel reprocessing. Essential thermodynamical data have been determined for the first time for the interactions of the plutonium at the (5+) oxidation state (main soluble species of Pu of the surface water) in inorganic media (chloride, nitrate, sulfate, carbonate). This study enables to correct the existing model, based on the thermodynamical data of the neptunium at the (5+) oxidation state (analogue of the pentavalent plutonium). Furthermore, the hyphenated CE-ICP-MS technique has also been applied to study the interactions between DTPA, widely used in the nuclear industry, and the elements at the (3+) oxidation state (Pu, Am, Cm, Cf) and at the (4+) oxidation state (Pu, Np, Th). The results show for the first time the formation of mixed An(IV)/DTPA/OH complexes likely to play a key role on the actinide behavior in the field of the waste management. The study on the trivalent elements confirms the selectivity of DTPA versus the actinide in the framework of the actinide/lanthanide separation but proves that the covalency, responsible of the selectivity, are less important than the ionicity in the binding. (author)

  1. Enhanced fullerene–Au(111 coupling in (2√3 × 2√3R30° superstructures with intermolecular interactions

    Directory of Open Access Journals (Sweden)

    Michael Paßens

    2015-06-01

    Full Text Available Disordered and uniform (2√3 × 2√3R30° superstructures of fullerenes on the Au(111 surface have been studied using scanning tunneling microscopy and spectroscopy. It is shown that the deposition and growth process of a fullerene monolayer on the Au(111 surface determine the resulting superstructure. The supply of thermal energy is of importance for the activation of a Au vacancy forming process and thus, one criterion for the selection of the respective superstructure. However, here it is depicted that a vacancy–adatom pair can be formed even at room temperature. This latter process results in C60 molecules that appear slightly more bright in scanning tunnelling microscopy images and are identified in disordered (2√3 x 2√3R30° superstructures based on a detailed structure analysis. In addition, these slightly more bright C60 molecules form uniform (2√3 x 2√3R30° superstructures, which exhibit intermolecular interactions, likely mediated by Au adatoms. Thus, vacancy–adatom pairs forming at room temperature directly affect the resulting C60 superstructure. Differential conductivity spectra reveal a lifting of the degeneracy of the LUMO and LUMO+1 orbitals in the uniform (2√3 x 2√3R30° superstructure and in addition, hybrid fullerene–Au(111 surface states suggest partly covalent interactions.

  2. Engineered analogues of cement/clay interactions in the Tournemire experimental platform (France): a coupled mineralogical and geochemical approach to track tiny disturbances

    International Nuclear Information System (INIS)

    Techer, Isabelle; Michel, Pauline; Tinseau, Elisabeth; Devol-Brown, Isabelle; Bartier, Daniele; Boulvais, Philippe; Suchorski, Krzysztof

    2012-01-01

    A scientific program has been especially established to better understand the high-pH fluids / clay interactions through a mineralogical and geochemical study of three engineered analogues available by means of the IRSN Tournemire experimental platform. This platform, located in Aveyron (France), is based on a tunnel, excavated between 1882 and 1886 through Domerian marls and Toarcian argillites, and is dedicated since 1990 to multidisciplinary research programs. Different contexts presenting the argillite formation in contact with a cementitious material are encountered and are linked to its historical construction and scientific evolution. These rare examples of cement / clay contacts maintained over time scales ranging from a few years to a hundred of years are studied as engineered analogues of a deep geological storage. This approach is moreover completed by experiments (diffusion and advection) performed in laboratory over shorter time and smaller space scales in order to discriminate and control the major parameters involved in such interactions (details are given in another paper). This paper presents the scientific program developed on the three engineered analogues: tunnel walls recovered by lime after excavation; four concreted exploration boreholes; two experimental research galleries excavated in 2003

  3. Evidence for the presence of U-Mo-Al ternary compounds in the U-Mo/Al interaction layer grown by thermal annealing: a coupled micro X-ray diffraction and micro X-ray absorption spectroscopy study

    International Nuclear Information System (INIS)

    Palancher, H.; Martin, P.; Nassif, V.

    2007-01-01

    The systematic presence of the ternary phases U 6 Mo 4 Al 43 and UMo 2 Al 20 is reported in a U-Mo/Al interaction layer grown by thermal annealing. This work shows, therefore, the low Mo solubility in UAl 3 and UAl 4 binary phases; it contradicts the hypothesis of the formation of (U,Mo)Al 3 and (U,Mo)Al 4 solid solutions often admitted in the literature. Using μ-XAS (micro X-ray absorption spectroscopy) at the Mo K edge and μ-XRD (micro X-ray diffraction), the heterogeneity of the interaction layer obtained on a γ-U 0.85 Mo 0.15 /Al diffusion couple has been precisely investigated. The UMo 2 Al 20 phase has been identified at the closest location from the Al side. Moreover, μ-XRD mapping performed on an annealed fuel plate enabled the characterization of the four phases resulting from the γ-U 0.85 Mo 0.15 /Al and (U 2 Mo+α-U)/Al interactions. A strong correlation between the concentrations of UAl 4 and UMo 2 Al 20 and those of UAl 3 and U 6 Mo 4 Al 43 has been shown. (orig.)

  4. Suppression of antiferromagnetic interactions through Cu vacancies in Mn-substituted CuInSe2 chalcopyrites

    International Nuclear Information System (INIS)

    Yao Jinlei; Brunetta, Carl D; Aitken, Jennifer A

    2012-01-01

    Stoichiometric and Cu-poor Cu 0.95-x Mn 0.05 InSe 2 (x = 0-0.20) compounds were synthesized by high-temperature, solid-state reactions. The presence of copper vacancies is revealed by Rietveld refinements of combined neutron and x-ray powder diffraction data. The antiferromagnetic interaction is depressed by the copper deficiency, which may be explained as the competition between the antiferromagnetic Mn-Se-eMn superexchange interaction and the hole-mediated ferromagnetic exchange induced by the copper vacancy. The introduction of copper vacancies is proposed to be a viable route to impart carrier-mediated ferromagnetic exchange in the chalcopyrite-based dilute magnetic semiconductors. (paper)

  5. A combined DFT and restricted open-shell configuration interaction method including spin-orbit coupling: Application to transition metal L-edge X-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Roemelt, Michael; Maganas, Dimitrios; Neese, Frank [Max-Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470 Muelheim an der Ruhr (Germany); DeBeer, Serena [Max-Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470 Muelheim an der Ruhr (Germany); Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853 (United States)

    2013-05-28

    A novel restricted-open-shell configuration interaction with singles (ROCIS) approach for the calculation of transition metal L-edge X-ray absorption spectra is introduced. In this method, one first calculates the ground state and a number of excited states of the non-relativistic Hamiltonian. By construction, the total spin is a good quantum number in each of these states. For a ground state with total spin S excited states with spin S Prime = S, S - 1, and S + 1 are constructed. Using Wigner-Eckart algebra, all magnetic sublevels with M{sub S}= S, Horizontal-Ellipsis , -S for each multiplet of spin S are obtained. The spin-orbit operator is represented by a mean-field approximation to the full Breit-Pauli spin-orbit operator and is diagonalized over this N-particle basis. This is equivalent to a quasi-degenerate treatment of the spin-orbit interaction to all orders. Importantly, the excitation space spans all of the molecular multiplets that arise from the atomic Russell-Saunders terms. Hence, the method represents a rigorous first-principles approach to the complicated low-symmetry molecular multiplet problem met in L-edge X-ray absorption spectroscopy. In order to gain computational efficiency, as well as additional accuracy, the excitation space is restricted to single excitations and the configuration interaction matrix is slightly parameterized in order to account for dynamic correlation effects in an average way. To this end, it is advantageous to employ Kohn-Sham rather than Hartree-Fock orbitals thus defining the density functional theory/ROCIS method. However, the method can also be used in an entirely non-empirical fashion. Only three global empirical parameters are introduced and have been determined here for future application of the method to any system containing any transition metal. The three parameters were carefully calibrated using the L-edge X-ray absorption spectroscopy spectra of a test set of coordination complexes containing first row

  6. Quantum entanglement and position–momentum entropic squeezing of a moving Lambda-type three-level atom interacting with a single-mode quantized field with intensity-dependent coupling

    International Nuclear Information System (INIS)

    Faghihi, M J; Tavassoly, M K

    2013-01-01

    In this paper, we study the interaction between a moving Λ-type three-level atom and a single-mode cavity field in the presence of intensity-dependent atom–field coupling. After obtaining the state vector of the entire system explicitly, we study the nonclassical features of the system such as quantum entanglement, position–momentum entropic squeezing, quadrature squeezing and sub-Poissonian statistics. According to the obtained numerical results we illustrate that the squeezed period, the duration of entropy squeezing and the maximal squeezing can be controlled by choosing the appropriate nonlinearity function together with entering the atomic motion effect by the suitable selection of the field-mode structure parameter. Also, the atomic motion, as well as the nonlinearity function, leads to the oscillatory behaviour of the degree of entanglement between the atom and field. (paper)

  7. Quantum entanglement and position-momentum entropic squeezing of a moving Lambda-type three-level atom interacting with a single-mode quantized field with intensity-dependent coupling

    Science.gov (United States)

    Faghihi, M. J.; Tavassoly, M. K.

    2013-07-01

    In this paper, we study the interaction between a moving Λ-type three-level atom and a single-mode cavity field in the presence of intensity-dependent atom-field coupling. After obtaining the state vector of the entire system explicitly, we study the nonclassical features of the system such as quantum entanglement, position-momentum entropic squeezing, quadrature squeezing and sub-Poissonian statistics. According to the obtained numerical results we illustrate that the squeezed period, the duration of entropy squeezing and the maximal squeezing can be controlled by choosing the appropriate nonlinearity function together with entering the atomic motion effect by the suitable selection of the field-mode structure parameter. Also, the atomic motion, as well as the nonlinearity function, leads to the oscillatory behaviour of the degree of entanglement between the atom and field.

  8. Study of Separation and Identification of the Active Ingredients in Gardenia jasminoides Ellis Based on a Two-Dimensional Liquid Chromatography by Coupling Reversed Phase Liquid Chromatography and Hydrophilic Interaction Liquid Chromatography.

    Science.gov (United States)

    Zhou, Xuan; Chen, Cen; Ye, Xiaolan; Song, Fenyun; Fan, Guorong; Wu, Fuhai

    2017-01-01

    In this paper, by coupling reversed phase liquid chromatography (RPLC) and hydrophilic interaction liquid chromatography (HILIC), a two-dimensional liquid chromatography system was developed for separation and identification of the active ingredients in Gardenia jasminoides Ellis (GJE). By applying the semi-preparative C18 column as the first dimension and the core-shell column as the second dimension, a total of 896 peaks of GJE were separated. Among the 896 peaks, 16 active ingredients including geniposide, gardenoside, gardoside, etc. were identified by mass spectrometry analysis. The results indicated that the proposed two-dimensional RPLC/HILIC system was an effective method for the analysis of GJE and might hold a high potential to become a useful tool for analysis of other complex mixtures. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Laser Shock Processing of Metallic Materials: Coupling of Laser-Plasma Interaction and Material Behaviour Models for the Assessment of Key Process Issues

    International Nuclear Information System (INIS)

    Ocana, J. L.; Morales, M.; Molpeceres, C.; Porro, J. A.

    2010-01-01

    Profiting by the increasing availability of laser sources delivering intensities above 109 W/cm 2 with pulse energies in the range of several Joules and pulse widths in the range of nanoseconds, laser shock processing (LSP) is consolidating as an effective technology for the improvement of surface mechanical and corrosion resistance properties of metals. The main advantage of the laser shock processing technique consists on its capability of inducing a relatively deep compression residual stresses field into metallic alloy pieces allowing an improved mechanical behaviour, explicitly, the life improvement of the treated specimens against wear, crack growth and stress corrosion cracking. Although significant work from the experimental side has been contributed to explore the optimum conditions of application of the treatments and to assess their ultimate capability to provide enhanced mechanical behaviour to work-pieces of typical materials, only limited attempts have been developed in the way of full comprehension and predictive assessment of the characteristic physical processes and material transformations with a specific consideration of real material properties. In the present paper, a review on the physical issues dominating the development of LSP processes from a high intensity laser-matter interaction point of view is presented along with the theoretical and computational methods developed by the authors for their predictive assessment and practical results at laboratory scale on the application of the technique to different materials.

  10. Scaling up complexity in host-pathogens interaction models. Comment on "Coupled disease-behavior dynamics on complex networks: A review" by Z. Wang et al.

    Science.gov (United States)

    Aguiar, Maíra

    2015-12-01

    Caused by micro-organisms that are pathogenic to the host, infectious diseases have caused debilitation and premature death to large portions of the human population, leading to serious social-economic concerns. The persistence and increase in the occurrence of infectious diseases as well the emergence or resurgence of vector-borne diseases are closely related with demographic factors such as the uncontrolled urbanization and remarkable population growth, political, social and economical changes, deforestation, development of resistance to insecticides and drugs and increased human travel. In recent years, mathematical modeling became an important tool for the understanding of infectious disease epidemiology and dynamics, addressing ideas about the components of host-pathogen interactions. Acting as a possible tool to understand, predict the spread of infectious diseases these models are also used to evaluate the introduction of intervention strategies like vector control and vaccination. Many scientific papers have been published recently on these topics, and most of the models developed try to incorporate factors focusing on several different aspects of the disease (and eventually biological aspects of the vector), which can imply rich dynamic behavior even in the most basic dynamical models. As one example to be cited, there is a minimalistic dengue model that has shown rich dynamic structures, with bifurcations (Hopf, pitchfork, torus and tangent bifurcations) up to chaotic attractors in unexpected parameter regions [1,2], which was able to describe the large fluctuations observed in empirical outbreak data [3,4].

  11. Coupled modelling (transport-reaction) of the fluid-clay interactions and their feed back on the physical properties of the bentonite engineered clay barrier system

    International Nuclear Information System (INIS)

    Marty, N.

    2006-11-01

    The originality of this work is to process feed back effects of mineralogical and chemical modifications of clays, in storage conditions, on their physical properties and therefore on their transport characteristics (porosity, molecular diffusion, permeability). These feed back effects are modelled using the KIRMAT code (Kinetic of Reaction and MAss Transfer) developed from the kinetic code KINDIS by adding the effect of water renewal in the mineral-solution reactive cells. KIRMAT resolves mass balance equations associated with mass transport together with the geochemical reactions in a 1D approach. After 100 000 years of simulated interaction at 100 C, with the fluid of the Callovo-Oxfordian geological level (COX) and with iron provided by the steel overpack corrosion, the montmorillonite of the clay barrier is only partially transformed (into illite, chlorite, saponite...). Only outer parts of the modelled profile seem to be significantly affected by smectite dissolution processes, mainly at the interface with the geological environment. The modifications of physical properties show a closure of the porosity at the boundaries of the barrier, by creating a decrease of mass transport by molecular diffusion, essentially at the interface with the iron. Permeability laws applied to this system show a decrease of the hydraulic conductivity correlated with the porosity evolution. Near the COX, the swelling pressure of the clays from the barrier decreases. In the major part of the modelled profile, the engineered clay barrier system seems to keep its initial physical properties (porosity, molecular diffusion, permeability, swelling pressure) and functionalities. (author)

  12. Identification of DNA-binding proteins that interact with the 5'-flanking region of the human D-amino acid oxidase gene by pull-down assay coupled with two-dimensional gel electrophoresis and mass spectrometry.

    Science.gov (United States)

    Tran, Diem Hong; Shishido, Yuji; Chung, Seong Pil; Trinh, Huong Thi Thanh; Yorita, Kazuko; Sakai, Takashi; Fukui, Kiyoshi

    2015-12-10

    D-Amino acid oxidase (DAO) is a flavoenzyme that metabolizes D-amino acids and is expected to be a promising therapeutic target of schizophrenia and glioblastoma. The study of DNA-binding proteins has yielded much information in the regulation of transcription and other biological processes. However, proteins interacting with DAO gene have not been elucidated. Our assessment of human DAO promoter activity using luciferase reporter system indicated the 5'-flanking region of this gene (-4289 bp from transcription initiation site) has a regulatory sequence for gene expression, which is regulated by multi-protein complexes interacting with this region. By using pull-down assay coupled with two-dimensional gel electrophoresis and mass spectrometry, we identified six proteins binding to the 5'-flanking region of the human DAO gene (zinc finger C2HC domain-containing protein 1A; histidine-tRNA ligase, cytoplasmic; molybdenum cofactor biosynthesis protein; 60S ribosomal protein L37; calponin-1; calmodulin binding protein and heterogeneous nuclear ribonucleoprotein A2/B1). These preliminary results will contribute to the advance in the understanding of the potential factors associated with the regulatory mechanism of DAO expression. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Coupled Acoustic-Mechanical Bandgaps

    DEFF Research Database (Denmark)

    Jensen, Jakob Søndergaard; Kook, Junghwan

    2016-01-01

    medium and the presence of acoustic resonances. It is demonstrated that corrugation of the plate structure can introduce bending wave bandgaps and bandgaps in the acoustic domain in overlapping and audible frequency ranges. This effect is preserved also when taking the physical coupling between the two...... domains into account. Additionally, the coupling is shown to introduce extra gaps in the band structure due to modal interaction and the appearance of a cut-on frequency for the fundamental acoustic mode....

  14. LIA longitudinal coupling impedance

    International Nuclear Information System (INIS)

    Faltens, A.

    1980-01-01

    The beam generated fields enter into the problems of waveform generation and longitudinal stability. In the former, provision must be made for the longitudinally defocusing forces due to the space charge and the beam loading effects on the accelerating voltage due to the current of a presumably known bunch. In the latter, the concern is for the growth of unintentional perturbations to unacceptably large values through the interaction of the charge and current fluctuations with the rest of the beam and the surrounding structures. These beam generated electric fields may be related to the beam current through a coupling impedance

  15. Interaction framework for loosely-coupled controllers

    DEFF Research Database (Denmark)

    Falsig, Simon

    2011-01-01

    terminology provide a common grounding for new work in the field of robotic controllers, whereas the TosNet framework allows researchers to focus on the actual functionality of robotic systems, and keeps them from wasting time implementing redundant, ad-hoc communication and infrastructure. It has been......Implementing communication and interfacing in research and prototype embedded systems is often done ad-hoc rather than in a standardized way. This leads to much time wasted due to redundantly implementing the same functionality in slightly different ways for each new project. This PhD project...... will aim to present both theoretical and practical work that can help reduce this waste by fostering reuse, simplicity and the use of a consistent, common terminology. Through a quick analysis of a few ad-hoc systems already implemented at the university, a number of undesirable characteristics...

  16. Systemic couple therapy for dysthymia.

    Science.gov (United States)

    Montesano, Adrián; Feixas, Guillem; Muñoz, Dámaris; Compañ, Victoria

    2014-03-01

    We examined the effect of Systemic Couple Therapy on a patient diagnosed with dysthymic disorder and her partner. Marge and Peter, a middle-aged married couple, showed significant and meaningful changes in their pattern of interaction over the course of the therapy and, by the end of it, Marge no longer met the diagnostic criteria for dysthymic disorder. Her scores on the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) and Beck Depression Inventory, Second Edition (BDI-II) were in the clinical range before treatment and in the nonclinical one at the end of therapy. Although scores on Dyadic Adjustment Scale showed different patterns, both members reported significant improvement. The analysis of change in the alliance-related behaviors throughout the process concurred with change in couple's pattern of interaction. Treatment effects were maintained at 12-month follow-up. Highlights in the therapy process showed the importance of relational mechanisms of change, such as broadening the therapeutic focus into the couple's pattern of interaction, reducing expressed emotion and resentment, as well as increasing positive exchanges. The results of this evidence-based case study should prompt further investigation of couple therapy for dysthymia disorder. Randomized clinical trial design is needed to reach an evidence-based treatment status. (c) 2014 APA, all rights reserved.

  17. Electronic properties of quasi one-dimensional quantum wire models under equal coupling strength superpositions of Rashba and Dresselhaus spin-orbit interactions in the presence of an in-plane magnetic field

    International Nuclear Information System (INIS)

    Papp, E.; Micu, C.; Racolta, D.

    2013-01-01

    In this paper one deals with the theoretical derivation of energy bands and of related wavefunctions characterizing quasi 1D semiconductor heterostructures, such as InAs quantum wire models. Such models get characterized this time by equal coupling strength superpositions of Rashba and Dresselhaus spin-orbit interactions of dimensionless magnitude a under the influence of in-plane magnetic fields of magnitude B. We found that the orientations of the field can be selected by virtue of symmetry requirements. For this purpose one resorts to spin conservations, but alternative conditions providing sensible simplifications of the energy-band formula can be reasonably accounted for. Besides the wavenumber k relying on the 1D electron, one deals with the spin-like s=±1 factors in the front of the square root term of the energy. Having obtained the spinorial wavefunction, opens the way to the derivation of spin precession effects. For this purpose one resorts to the projections of the wavenumber operator on complementary spin states. Such projections are responsible for related displacements proceeding along the Ox-axis. This results in a 2D rotation matrix providing both the precession angle as well as the precession axis

  18. Characteristics of persistent spin current components in a quasi-periodic Fibonacci ring with spin–orbit interactions: Prediction of spin–orbit coupling and on-site energy

    International Nuclear Information System (INIS)

    Patra, Moumita; Maiti, Santanu K.

    2016-01-01

    In the present work we investigate the behavior of all three components of persistent spin current in a quasi-periodic Fibonacci ring subjected to Rashba and Dresselhaus spin–orbit interactions. Analogous to persistent charge current in a conducting ring where electrons gain a Berry phase in presence of magnetic flux, spin Berry phase is associated during the motion of electrons in presence of a spin–orbit field which is responsible for the generation of spin current. The interplay between two spin–orbit fields along with quasi-periodic Fibonacci sequence on persistent spin current is described elaborately, and from our analysis, we can estimate the strength of any one of two spin–orbit couplings together with on-site energy, provided the other is known. - Highlights: • Determination of Rashba and Dresselhaus spin–orbit fields is discussed. • Characteristics of all three components of spin current are explored. • Possibility of estimating on-site energy is given. • Results can be generalized to any lattice models.

  19. Aromatic interactions impact ligand binding and function at serotonin 5-HT2C G protein-coupled receptors: receptor homology modelling, ligand docking, and molecular dynamics results validated by experimental studies

    Science.gov (United States)

    Córdova-Sintjago, Tania; Villa, Nancy; Fang, Lijuan; Booth, Raymond G.

    2014-02-01

    The serotonin (5-hydroxytryptamine, 5-HT) 5-HT2 G protein-coupled receptor (GPCR) family consists of types 2A, 2B, and 2C that share ∼75% transmembrane (TM) sequence identity. Agonists for 5-HT2C receptors are under development for psychoses; whereas, at 5-HT2A receptors, antipsychotic effects are associated with antagonists - in fact, 5-HT2A agonists can cause hallucinations and 5-HT2B agonists cause cardiotoxicity. It is known that 5-HT2A TM6 residues W6.48, F6.51, and F6.52 impact ligand binding and function; however, ligand interactions with these residues at the 5-HT2C receptor have not been reported. To predict and validate molecular determinants for 5-HT2C-specific activation, results from receptor homology modelling, ligand docking, and molecular dynamics simulation studies were compared with experimental results for ligand binding and function at wild type and W6.48A, F6.51A, and F6.52A point-mutated 5-HT2C receptors.

  20. Theoretical and experimental studies of a planar inductive coupled rf plasma source as the driver in simulator facility (ISTAPHM) of interactions of waves with the edge plasma on tokamaks

    Science.gov (United States)

    Ghanei, V.; Nasrabadi, M. N.; Chin, O.-H.; Jayapalan, K. K.

    2017-11-01

    This research aims to design and build a planar inductive coupled RF plasma source device which is the driver of the simulator project (ISTAPHM) of the interactions between ICRF Antenna and Plasma on tokamak by using the AMPICP model. For this purpose, a theoretical derivation of the distribution of the RF magnetic field in the plasma-filled reactor chamber is presented. An experimental investigation of the field distributions is described and Langmuir measurements are developed numerically. A comparison of theory and experiment provides an evaluation of plasma parameters in the planar ICP reactor. The objective of this study is to characterize the plasma produced by the source alone. We present the results of the first analysis of the plasma characteristics (plasma density, electron temperature, electron-ion collision frequency, particle fluxes and their velocities, stochastic frequency, skin depth and electron energy distribution functions) as function of the operating parameters (injected power, neutral pressure and magnetic field) as measured with fixed and movable Langmuir probes. The plasma is currently produced only by the planar ICP. The exact goal of these experiments is that the produced plasma by external source can exist as a plasma representative of the edge of tokamaks.

  1. Dynamics of entropy and nonclassical properties of the state of a Λ-type three-level atom interacting with a single-mode cavity field with intensity-dependent coupling in a Kerr medium

    International Nuclear Information System (INIS)

    Faghihi, M J; Tavassoly, M K

    2012-01-01

    In this paper, we study the interaction between a three-level atom and a quantized single-mode field with ‘intensity-dependent coupling’ in a ‘Kerr medium’. The three-level atom is considered to be in a Λ-type configuration. Under particular initial conditions, which may be prepared for the atom and the field, the dynamical state vector of the entire system will be explicitly obtained, for the arbitrary nonlinearity function f(n) associated with any physical system. Then, after evaluating the variation of the field entropy against time, we will investigate the quantum statistics as well as some of the nonclassical properties of the introduced state. During our calculations we investigate the effects of intensity-dependent coupling, Kerr medium and detuning parameters on the depth and domain of the nonclassicality features of the atom–field state vector. Finally, we compare our obtained results with those of V-type three-level atoms. (paper)

  2. Dynamics of entropy and nonclassical properties of the state of a Λ-type three-level atom interacting with a single-mode cavity field with intensity-dependent coupling in a Kerr medium

    Science.gov (United States)

    Faghihi, M. J.; Tavassoly, M. K.

    2012-02-01

    In this paper, we study the interaction between a three-level atom and a quantized single-mode field with ‘intensity-dependent coupling’ in a ‘Kerr medium’. The three-level atom is considered to be in a Λ-type configuration. Under particular initial conditions, which may be prepared for the atom and the field, the dynamical state vector of the entire system will be explicitly obtained, for the arbitrary nonlinearity function f(n) associated with any physical system. Then, after evaluating the variation of the field entropy against time, we will investigate the quantum statistics as well as some of the nonclassical properties of the introduced state. During our calculations we investigate the effects of intensity-dependent coupling, Kerr medium and detuning parameters on the depth and domain of the nonclassicality features of the atom-field state vector. Finally, we compare our obtained results with those of V-type three-level atoms.

  3. Number-phase entropic squeezing and nonclassical properties of a three-level atom interacting with a two-mode field: intensity-dependent coupling, deformed Kerr medium, and detuning effects

    Science.gov (United States)

    Faghihi, Mohammad Javad; Tavassoly, Mohammad Kazem

    2013-11-01

    In this paper, we follow our presented model in J. Opt. Soc. Am. B {\\bf 30}, 1109--1117 (2013), in which the interaction between a $\\Lambda$-type three-level atom and a quantized two-mode radiation field in a cavity in the presence of nonlinearities is studied. After giving a brief review on the procedure of obtaining the state vector of the atom-field system, some further interesting and important physical features (which are of particular interest in the quantum optics field of research) of the whole system state, i.e., the number-phase entropic uncertainty relation (based on the two-mode Pegg-Barnett formalism) and some of the nonclassicality signs consist of sub-Poissonian statistics, Cauchy-Schwartz inequality and two kinds of squeezing phenomenon are investigated. During our presentation, the effects of intensity-dependent coupling, deformed Kerr medium and the detuning parameters on the depth and domain of each of the mentioned nonclassical criteria of the considered quantum system are studied, in detail. It is shown that each of the mentioned nonclassicality aspects can be obtained by appropriately choosing the related parameters.

  4. Comprehensive Two-Dimensional Hydrophilic Interaction Chromatography (HILIC) × Reversed-Phase Liquid Chromatography Coupled to High-Resolution Mass Spectrometry (RP-LC-UV-MS) Analysis of Anthocyanins and Derived Pigments in Red Wine.

    Science.gov (United States)

    Willemse, Chandré M; Stander, Maria A; Vestner, Jochen; Tredoux, Andreas G J; de Villiers, André

    2015-12-15

    Changes in anthocyanin chemistry represent some of the most important transformations involved in red wine aging. However, accurate analysis of the derived pigments, as required to study the evolution of anthocyanins and tannins during aging, is hampered by their extreme structural diversity, low levels, and the fact that many of these compounds have identical mass spectral characteristics. In this context, chromatographic separation is critical. In this contribution, the application of online hydrophilic interaction chromatography (HILIC) × reversed-phase liquid chromatography (RP-LC) separation coupled to high-resolution mass spectrometry (MS) is described for the detailed characterization of anthocyanins and their derived pigments in aged red wine. A systematic approach was followed for the optimization of HILIC × RP-LC separation parameters using a capillary liquid chromatography (LC) system in the first dimension and an ultrahigh-pressure LC system in the second dimension to ensure maximum sensitivity and performance. Ninety four (94) anthocyanin-derived pigments were tentatively identified in one- and six-year-old Pinotage wines using accurate mass and fragmentation information obtained using quadrupole-time-of-flight mass spectrometry (Q-TOF-MS). Online HILIC × RP-LC-MS was found to offer high-resolution separation, because of the combination of two different separation modes, while the structured elution order observed improved the certainty in compound identification. Therefore, this approach shows promise for the detailed elucidation of the chemical alteration of anthocyanins during wine aging.

  5. Investigation of the temporal development of the stratospheric ozone layer with an interactively coupled chemistry-climate model; Untersuchung der zeitlichen Entwicklung der stratosphaerischen Ozonschicht mit einem interaktiv gekoppelten Klima-Chemie-Modell

    Energy Technology Data Exchange (ETDEWEB)

    Schnadt, C

    2001-07-01

    The impact of climate change and stratospheric chlorine loading on the stratospheric ozone layer is estimated by evaluating three multi-annual simulations of the interactively coupled global chemistry-climate model ECUAM4.L39 (DLR)/CHEM. Two experiments of the near past were carried out representing the early 1980s and 1990s, respectively. An additional scenario was conducted which is characterised by increased greenhouse gas concentrations and a slightly reduced stratospheric chlorine loading with respect to its value measured in the year 1990, according to current projections. The model is able to describe dynamic and chemical processes of the 1980s and 1990s realistically, and it is capable in reproducing the observed stratospheric temperature, water vapour, and ozone temperature trends of this time period. With increasing greenhouse gas concentrations, the model produces an enhancing stratospheric cooling for the years 1980 to 2015. Despite the reduced stratospheric chlorine loading in 2015, the decreased stratospheric temperatures will cause a continued reduction of stratospheric ozone in the southern hemisphere. In the northern hemisphere, tropospheric warming results in a changed excitation of planetary waves. Their vertical propagation and breaking in the stratosphere causes the polar vortex to become more unstable in 2015. This overcompensates the radiative stratospheric cooling so that stratospheric ozone recovers. (orig.)

  6. Comprehensive two-dimensional HPLC to study the interaction of multiple components in Rheum palmatum L. with HSA by coupling a silica-bonded HSA column to a silica monolithic ODS column.

    Science.gov (United States)

    Hu, Lianghai; Li, Xin; Feng, Shun; Kong, Liang; Su, Xingye; Chen, Xueguo; Qin, Feng; Ye, Mingliang; Zou, Hanfa

    2006-04-01

    A mode of comprehensive 2-D LC was developed by coupling a silica-bonded HSA column to a silica monolithic ODS column. This system combined the affinity property of the HSA column and the high-speed separation ability of the monolithic ODS column. The affinity chromatography with HSA-immobilized stationary phase was applied to study the interaction of multiple components in traditional Chinese medicines (TCMs) with HSA according to their affinity to protein in the first dimension. Then the unresolved components retained on the HSA column were further separated on the silica monolithic ODS column in the second dimension. By hyphenating the 2-D separation system to diode array detector and MS detectors, the UV and molecular weight information of the separated compounds can also be obtained. The developed separation system was applied to analysis of the extract of Rheum palmatum L., a number of low-abundant components can be separated on a single peak from the HSA column after normalization of peak heights. Six compounds were preliminarily identified according to their UV and MS spectra. It showed that this system was very useful for biological fingerprinting analysis of the components in TCMs and natural products.

  7. Characteristics of persistent spin current components in a quasi-periodic Fibonacci ring with spin–orbit interactions: Prediction of spin–orbit coupling and on-site energy

    Energy Technology Data Exchange (ETDEWEB)

    Patra, Moumita; Maiti, Santanu K., E-mail: santanu.maiti@isical.ac.in

    2016-12-15

    In the present work we investigate the behavior of all three components of persistent spin current in a quasi-periodic Fibonacci ring subjected to Rashba and Dresselhaus spin–orbit interactions. Analogous to persistent charge current in a conducting ring where electrons gain a Berry phase in presence of magnetic flux, spin Berry phase is associated during the motion of electrons in presence of a spin–orbit field which is responsible for the generation of spin current. The interplay between two spin–orbit fields along with quasi-periodic Fibonacci sequence on persistent spin current is described elaborately, and from our analysis, we can estimate the strength of any one of two spin–orbit couplings together with on-site energy, provided the other is known. - Highlights: • Determination of Rashba and Dresselhaus spin–orbit fields is discussed. • Characteristics of all three components of spin current are explored. • Possibility of estimating on-site energy is given. • Results can be generalized to any lattice models.

  8. A Pronoun Analysis of Couples' Support Transactions.

    Science.gov (United States)

    Hinnekens, Céline; Lemmens, Gilbert; Vanhee, Gaëlle; Verhofstadt, Lesley

    2016-01-01

    The present study collected data about couples' level of relationship quality and their usage of pronouns that express we-ness or separateness in the context of support interactions. The sample consisted of 48 couples in a long-term relationship who provided questionnaire data and participated in two videotaped social support interaction tasks. Couples' videotaped interactions were subsequently coded for the number of personal pronouns-we-words (e.g., we, ours, ourselves) versus you and me-words (e.g., me, mine, you, yours)-used by both partners.

  9. Chameleons with Field Dependent Couplings

    CERN Document Server

    Brax, Philippe; Mota, David F; Nunes, Nelson J; Winther, Hans A

    2010-01-01

    Certain scalar-tensor theories exhibit the so-called chameleon mechanism, whereby observational signatures of scalar fields are hidden by a combination of self-interactions and interactions with ambient matter. Not all scalar-tensor theories exhibit such a chameleon mechanism, which has been originally found in models with inverse power run-away potentials and field independent couplings to matter. In this paper we investigate field-theories with field-dependent couplings and a power-law potential for the scalar field. We show that the theory indeed is a chameleon field theory. We find the thin-shell solution for a spherical body and investigate the consequences for E\\"ot-Wash experiments, fifth-force searches and Casimir force experiments. Requiring that the scalar-field evades gravitational tests, we find that the coupling is sensitive to a mass-scale which is of order of the Hubble scale today.

  10. Coupling Functions Enable Secure Communications

    Science.gov (United States)

    Stankovski, Tomislav; McClintock, Peter V. E.; Stefanovska, Aneta

    2014-01-01

    Secure encryption is an essential feature of modern communications, but rapid progress in illicit decryption brings a continuing need for new schemes that are harder and harder to break. Inspired by the time-varying nature of the cardiorespiratory interaction, here we introduce a new class of secure communications that is highly resistant to conventional attacks. Unlike all earlier encryption procedures, this cipher makes use of the coupling functions between interacting dynamical systems. It results in an unbounded number of encryption key possibilities, allows the transmission or reception of more than one signal simultaneously, and is robust against external noise. Thus, the information signals are encrypted as the time variations of linearly independent coupling functions. Using predetermined forms of coupling function, we apply Bayesian inference on the receiver side to detect and separate the information signals while simultaneously eliminating the effect of external noise. The scheme is highly modular and is readily extendable to support different communications applications within the same general framework.

  11. Cognitive-behavioral couple therapy.

    Science.gov (United States)

    Epstein, Norman B; Zheng, Le

    2017-02-01

    This article describes how cognitive-behavioral couple therapy (CBCT) provides a good fit for intervening with a range of stressors that couples experience from within and outside their relationship. It takes an ecological perspective in which a couple is influenced by multiple systemic levels. We provide an overview of assessment and intervention strategies used to modify negative behavioral interaction patterns, inappropriate or distorted cognitions, and problems with the experience and regulation of emotions. Next, we describe how CBCT can assist couples in coping with stressors involving (a) a partner's psychological disorder (e.g. depression), (b) physical health problems (e.g. cancer), (c) external stressors (e.g. financial strain), and (d) severe relational problems (e.g. partner aggression). Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. 基于和谐耦合的领导方式互动过程:一种新的阐释%Interaction of Leading Pattern Based on "He Xie Coupling":A New Interpretation

    Institute of Scientific and Technical Information of China (English)

    李鹏飞; 葛京

    2016-01-01

    By applying He Xie Management Theory,leaders apply two kinds of leader ship approaches toa chievingor-ganization goals which are He Principle leadership approach and Xie Principle leadership approach.He and Xie Cou-pling represents the interaction and conversion between He Principle leadership approach and Xie Principle leadership approach,while He Principle leadership approach is to cope with the uncertainty by motivating the organization member to take agentic actions.Based on the research,this study categorizes He Principle leadership approach into contextual He Principle approach and fundamental He Principle approach,and discusses the interaction process of the three leader-ship approaches which are Xie Principle leadership approach,contextual He Principle approach and fundamental He Principle approach as well under the three contexts:weak uncertainty,strong uncertainty,and the combination of cer-tainty and uncertainty.Finally,the effect of contextual change,from certainty to uncertainty and from uncertainty to cer-tainty,on interaction process of the three leadership approaches is discussed.%和则与谐则是两种潜在的领导者达成组织目标可以运用的领导方式,和谐耦合体现为这两类领导方式的互动与转化。和则通过激发组织成员的能动性应对不确定性,在已有研究基础上,尝试将和则方式分为基础和则方式与情境和则方式两类,并区分弱不确定、强不确定、确定与不确定交织三种情境探讨了基础和则、情境和则与谐则三类领导方式的互动过程,纳入情境变化讨论了确定转不确定、不确定转确定两种情境变化对三类领导方式互动过程的影响。

  13. Optimization of mixed quantum-classical dynamics: Time-derivative coupling terms and selected couplings

    International Nuclear Information System (INIS)

    Pittner, Jiri; Lischka, Hans; Barbatti, Mario

    2009-01-01

    The usage of time-derivative non-adiabatic coupling terms and partially coupled time-dependent equations are investigated to accelerate non-adiabatic dynamics simulations at multireference configuration interaction (MRCI) level. The quality of the results and computational costs are compared against non-adiabatic benchmark dynamics calculations using non-adiabatic coupling vectors. In the comparison between the time-derivative couplings and coupling vectors, deviations in the adiabatic population of individual trajectories were observed in regions of rapid variation of the coupling terms. They, however, affected the average adiabatic population to only about 5%. For small multiconfiguration spaces, dynamics with time-derivative couplings are significantly faster than those with coupling vectors. This relation inverts for larger configuration spaces. The use of the partially coupled equations approach speeds up the simulations significantly while keeping the deviations in the population below few percent. Imidazole and the methaniminium cation are used as test examples

  14. Dynamics of nonlinear oscillators with time-varying conjugate coupling

    Indian Academy of Sciences (India)

    oscillators. We analyze the behavior of coupled systems with respect to the coupling switching frequency using ..... are of potential utility in appropriate design strategies and/or understanding of complex systems with dynamic interaction ...

  15. Hadronic couplings of open beauty states

    International Nuclear Information System (INIS)

    Ram, S.N.; Singh, C.P.

    1982-08-01

    Strong interaction coupling parameters of particles with beauty quantum number are obtained using dispersion sum rules in various forms, e.g. current algebra sum rules, superconvergence sum rules and finite energy sum rules etc. These sum rules lead to a set of algebraic relations among masses and coupling constants. We compare the hadronic couplings of beautiful particles as obtained from various techniques and discuss their implications on the hadronic production of these states. (author)

  16. Multiquark interactions

    International Nuclear Information System (INIS)

    Luk'yanov, V.K.

    1984-01-01

    To study multiquark interactions (MQI) the data of experiments confirming the presence of 3q, 6q, 12q states in interacting nuclear nucleons, in hadron- and lepton-nuclear processes at high energies and high momentum transfers are considered. Experimental data on cumulative processes pointing to the existence of MQI are analyzed. Two-channel model of a nucleus (the model of interacting nucleons) in the theory of coupled channels is discussed. The behaviour of form factor of deuteron and NQI (6q) contributions to ed scattering as well as deep inelastic scattering on nuclei are studied. The data known as EMC effect are discussed. It is pointed out that introduction of the notion MQI and consideration of a nucleus as a system of nucleons with a low MQI addition will help to explain such processes as cumulative reactions, form factors of a deuteron and light nuclei, deep inelastic scattering on nuclei

  17. Electronic structure and microscopic model of CoNb2O6

    Science.gov (United States)

    Molla, Kaimujjaman; Rahaman, Badiur

    2018-05-01

    We present the first principle density functional calculations to figure out the underlying spin model of CoNb2O6. The first principles calculations define the main paths of superexchange interaction between Co spins in this compound. We discuss the nature of the exchange paths and provide quantitative estimates of magnetic exchange couplings. A microscopic modeling based on analysis of the electronic structure of this system puts it in the interesting class of weakly couple geometrically frustrated isosceles triangular Ising antiferromagnet.

  18. Molecular interactions of agonist and inverse agonist ligands at serotonin 5-HT2C G protein-coupled receptors: computational ligand docking and molecular dynamics studies validated by experimental mutagenesis results

    Science.gov (United States)

    Córdova-Sintjago, Tania C.; Liu, Yue; Booth, Raymond G.

    2015-02-01

    To understand molecular determinants for ligand activation of the serotonin 5-HT2C G protein-coupled receptor (GPCR), a drug target for obesity and neuropsychiatric disorders, a 5-HT2C homology model was built according to an adrenergic β2 GPCR (β2AR) structure and validated using a 5-HT2B GPCR crystal structure. The models were equilibrated in a simulated phosphatidyl choline membrane for ligand docking and molecular dynamics studies. Ligands included (2S, 4R)-(-)-trans-4-(3'-bromo- and trifluoro-phenyl)-N,N-dimethyl-1,2,3,4-tetrahydronaphthalene-2-amine (3'-Br-PAT and 3'-CF3-PAT), a 5-HT2C agonist and inverse agonist, respectively. Distinct interactions of 3'-Br-PAT and 3'-CF3-PAT at the wild-type (WT) 5-HT2C receptor model were observed and experimental 5-HT2C receptor mutagenesis studies were undertaken to validate the modelling results. For example, the inverse agonist 3'-CF3-PAT docked deeper in the WT 5-HT2C binding pocket and altered the orientation of transmembrane helices (TM) 6 in comparison to the agonist 3'-Br-PAT, suggesting that changes in TM orientation that result from ligand binding impact function. For both PATs, mutation of 5-HT2C residues S3.36, T3.37, and F5.47 to alanine resulted in significantly decreased affinity, as predicted from modelling results. It was concluded that upon PAT binding, 5-HT2C residues T3.37 and F5.47 in TMs 3 and 5, respectively, engage in inter-helical interactions with TMs 4 and 6, respectively. The movement of TMs 5 and 6 upon agonist and inverse agonist ligand binding observed in the 5-HT2C receptor modelling studies was similar to movements reported for the activation and deactivation of the β2AR, suggesting common mechanisms among aminergic neurotransmitter GPCRs.

  19. Separation and characterization of chemical constituents in Ginkgo biloba extract by off-line hydrophilic interaction×reversed-phase two-dimensional liquid chromatography coupled with quadrupole-time of flight mass spectrometry.

    Science.gov (United States)

    Ji, Shuai; He, Dan-Dan; Wang, Tian-Yun; Han, Jie; Li, Zheng; Du, Yan; Zou, Jia-Hui; Guo, Meng-Zhe; Tang, Dao-Quan

    2017-11-30

    Ginkgo biloba extract (GBE), derived from the leaves of Ginkgo biloba L., is one of the most widely used traditional Chinese medicines worldwide. Due to high structural diversity and low abundance of chemical constituents in GBE, conventional reversed-phase liquid chromatography has limited power to meet the needs of its quality control. In this study, an off-line hydrophilic interaction×reversed-phase two-dimensional liquid chromatography (HILIC×RP 2D-LC) system coupled with diode array detection (DAD) and quadrupole time-of-flight mass spectrometry (qTOF-MS) was established to comprehensively analyze the chemical constituents of GBE. After optimizing the chromatographic columns and mobile phase of 2D-LC, a Waters XBridge Amide column using acetonitrile/water/formic acid as the mobile phase was selected as the first dimension to fractionate GBE, and the obtained fractions were further separated on an Agilent Zorbax XDB-C18 column with methanol/water/formic acid as the mobile phase. As a result, a total of 125 compounds were detected in GBE. The orthogonality of the 2D-LC system was 69.5%, and the practical peak capacity was 3864 and 2994, respectively, calculated by two different methods. The structures of 104 compounds were tentatively characterized by qTOF-MS analysis, and 21 of them were further confirmed by comparing with reference standards. This established HILIC×RP 2D-LC-qTOF/MS system can greatly improve the separation and characterization of natural products in GBE or other complicated herbal extracts. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. XMCD for monitoring exchange interactions. The role of the Gd 4f and 5d orbitals in metal-nitronyl nitroxide magnetic chains.

    Science.gov (United States)

    Champion, Guillaume; Lalioti, Nikolia; Tangoulis, Vassilis; Arrio, Marie-Anne; Sainctavit, Philippe; Villain, Françoise; Caneschi, Andrea; Gatteschi, Dante; Giorgetti, Christine; Baudelet, François; Verdaguer, Michel; Cartier dit Moulin, Christophe

    2003-07-09

    We report here the X-ray magnetic circular dichroism (XMCD) study at the Gd M(4,5)- and L(2,3)-edges of two linear magnetic chains involving Gd(III) cations bridged by nitronyl nitroxide radicals. This spectroscopy directly probes the magnetic moments of the 4f and 5d orbitals of the gadolinium ions. We compare macroscopic magnetic measurements and local XMCD signals. The M(4,5)-edges results are in agreement with the J values extracted from the fits of the SQUID magnetic measurements. The L(2,3)-edges signals show that the electronic density in the Gd 5d orbitals depends on the neighbors of the gadolinium cations. Nevertheless, the 5d orbitals do not seem to play any role in the superexchange pathway between radicals through the metal ion proposed to explain the particular magnetic exchange interactions between the radicals in these chains.

  1. Fluid structure coupling algorithm

    International Nuclear Information System (INIS)

    McMaster, W.H.; Gong, E.Y.; Landram, C.S.; Quinones, D.F.

    1980-01-01

    A fluid-structure-interaction algorithm has been developed and incorporated into the two-dimensional code PELE-IC. This code combines an Eulerian incompressible fluid algorithm with a Lagrangian finite element shell algorithm and incorporates the treatment of complex free surfaces. The fluid structure and coupling algorithms have been verified by the calculation of solved problems from the literature and from air and steam blowdown experiments. The code has been used to calculate loads and structural response from air blowdown and the oscillatory condensation of steam bubbles in water suppression pools typical of boiling water reactors. The techniques developed have been extended to three dimensions and implemented in the computer code PELE-3D

  2. COUPLED CHEMOTAXIS FLUID MODEL

    KAUST Repository

    LORZ, ALEXANDER

    2010-06-01

    We consider a model system for the collective behavior of oxygen-driven swimming bacteria in an aquatic fluid. In certain parameter regimes, such suspensions of bacteria feature large-scale convection patterns as a result of the hydrodynamic interaction between bacteria. The presented model consist of a parabolicparabolic chemotaxis system for the oxygen concentration and the bacteria density coupled to an incompressible Stokes equation for the fluid driven by a gravitational force of the heavier bacteria. We show local existence of weak solutions in a bounded domain in d, d = 2, 3 with no-flux boundary condition and in 2 in the case of inhomogeneous Dirichlet conditions for the oxygen. © 2010 World Scientific Publishing Company.

  3. Nuclear beta decay and the weak interaction

    International Nuclear Information System (INIS)

    Kean, D.C.

    1975-11-01

    Short notes are presented on various aspects of nuclear beta decay and weak interactions including: super-allowed transitions, parity violation, interaction strengths, coupling constants, and the current-current formalism of weak interaction. (R.L.)

  4. Preliminary Studies of Na{sub 2}CO{sub 3} Cleaning from Na-CO{sub 2} Interaction in S-CO{sub 2} Power Cycle coupled to SFR System

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Hwa-Young; Lee, Jeong Ik [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Wi, Myung-Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Ahn, Hong Joo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    Once the flow channel is plugged, to replace the plugged channel, the whole system operation should be stopped or a bypass system is necessary.. Therefore, finding a material which can clean up the solid reaction products from Na-CO{sub 2} interaction and the contaminated system with little or no impact on economics can be a valuable research. Hence, a screening process of selecting candidate materials was adopted to find a potential substance which can act as a cleaning agent in the previous study. It is essential to ensure the system economics as well as safety of SFR coupled with S-CO{sub 2} Brayton power conversion system. For this reason, the experiment was conducted to see the possibility of reaction between each selected potential substance and Na{sub 2}CO{sub 3}, which is the major product of the reaction. Na{sub 2}CO{sub 3} does not melt before 856 .deg. C This study was performed with the collaboration of Korea Atomic Energy Research Institute (KAERI) and Korea Advanced Institute of Science and Technology (KAIST). Liquid sodium and CO{sub 2} gas would react then produce the solid reaction products when the pressure boundary of sodium-CO{sub 2} heat exchanger fails. The solid reaction products are possible to plug the narrow flow channel of PCHE and this concerns the system economics. Thus, it is necessary to search a method for cleaning the solid reaction products which is mainly Na{sub 2}CO{sub 3}. From the preliminary study, some sodium-based compounds were selected and the mixtures of several sodium-based compounds with Na{sub 2}CO{sub 3} were thermally analyzed by the TG/DTA studies. Unfortunately, the selected sodium-based compounds, NaBrO{sub 3}, NaClO{sub 3} and NaBF{sub 4}, decomposed before 600 .deg. C and did not react with Na{sub 2}CO{sub 3}. In the near future, further research will be performed to search other compounds for cleaning the solid reaction products.

  5. High-throughput hydrophilic interaction chromatography coupled to tandem mass spectrometry for the optimized quantification of the anti-Gram-negatives antibiotic colistin A/B and its pro-drug colistimethate.

    Science.gov (United States)

    Mercier, Thomas; Tissot, Fréderic; Gardiol, Céline; Corti, Natascia; Wehrli, Stéphane; Guidi, Monia; Csajka, Chantal; Buclin, Thierry; Couet, William; Marchetti, Oscar; Decosterd, Laurent A

    2014-11-21

    Colistin is a last resort's antibacterial treatment in critically ill patients with multi-drug resistant Gram-negative infections. As appropriate colistin exposure is the key for maximizing efficacy while minimizing toxicity, individualized dosing optimization guided by therapeutic drug monitoring is a top clinical priority. Objective of the present work was to develop a rapid and robust HPLC-MS/MS assay for quantification of colistin plasma concentrations. This novel methodology validated according to international standards simultaneously quantifies the microbiologically active compounds colistin A and B, plus the pro-drug colistin methanesulfonate (colistimethate, CMS). 96-well micro-Elution SPE on Oasis Hydrophilic-Lipophilic-Balanced (HLB) followed by direct analysis by Hydrophilic Interaction Liquid Chromatography (HILIC) with Ethylene Bridged Hybrid--BEH--Amide phase column coupled to tandem mass spectrometry allows a high-throughput with no significant matrix effect. The technique is highly sensitive (limit of quantification 0.014 and 0.006 μg/mL for colistin A and B), precise (intra-/inter-assay CV 0.6-8.4%) and accurate (intra-/inter-assay deviation from nominal concentrations -4.4 to +6.3%) over the clinically relevant analytical range 0.05-20 μg/mL. Colistin A and B in plasma and whole blood samples are reliably quantified over 48 h at room temperature and at +4°C (<6% deviation from nominal values) and after three freeze-thaw cycles. Colistimethate acidic hydrolysis (1M H2SO4) to colistin A and B in plasma was completed in vitro after 15 min of sonication while the pro-drug hydrolyzed spontaneously in plasma ex vivo after 4 h at room temperature: this information is of utmost importance for interpretation of analytical results. Quantification is precise and accurate when using serum, citrated or EDTA plasma as biological matrix, while use of heparin plasma is not appropriate. This new analytical technique providing optimized quantification in real

  6. A library of 7TM receptor C-terminal tails - Interactions with the proposed post-endocytic sorting proteins ERM-binding phosphoprotein 50 (EBP50), N-ethylmaleimide-sensitive factor (NSF), sorting nexin 1 (SNX1), and G protein-coupled receptor-associated sorting protein (GASP)

    DEFF Research Database (Denmark)

    Heydorn, A.; Sondergaard, B.P.; Ersbøll, Bjarne Kjær

    2004-01-01

    Adaptor and scaffolding proteins determine the cellular targeting, the spatial, and thereby the functional association of G protein-coupled seven-transmembrane receptors with co-receptors, transducers, and downstream effectors and the adaptors determine post-signaling events such as receptor...... only a single receptor tail, i.e. the beta(2)-adrenergic receptor, whereas N-ethylmaleimide-sensitive factor bound 11 of the tail-fusion proteins. Of the two proteins proposed to target receptors for lysosomal degradation, sorting nexin 1 (SNX1) bound 10 and the C-terminal domain of G protein...... the expected nanomolar affinities for interaction with SNX1. Truncations of the NK1 receptor revealed that an extended binding epitope is responsible for the interaction with both SNX1 and G protein-coupled receptor-associated sorting protein as well as with N-ethylmaleimide-sensitive factor. It is concluded...

  7. A library of 7TM receptor C-terminal tails. Interactions with the proposed post-endocytic sorting proteins ERM-binding phosphoprotein 50 (EBP50), N-ethylmaleimide-sensitive factor (NSF), sorting nexin 1 (SNX1), and G protein-coupled receptor-associated sorting protein (GASP)

    DEFF Research Database (Denmark)

    Heydorn, Arne; Søndergaard, Birgitte P; Ersbøll, Bjarne

    2004-01-01

    Adaptor and scaffolding proteins determine the cellular targeting, the spatial, and thereby the functional association of G protein-coupled seven-transmembrane receptors with co-receptors, transducers, and downstream effectors and the adaptors determine post-signaling events such as receptor...... only a single receptor tail, i.e. the beta(2)-adrenergic receptor, whereas N-ethylmaleimide-sensitive factor bound 11 of the tail-fusion proteins. Of the two proteins proposed to target receptors for lysosomal degradation, sorting nexin 1 (SNX1) bound 10 and the C-terminal domain of G protein...... the expected nanomolar affinities for interaction with SNX1. Truncations of the NK(1) receptor revealed that an extended binding epitope is responsible for the interaction with both SNX1 and G protein-coupled receptor-associated sorting protein as well as with N-ethylmaleimide-sensitive factor. It is concluded...

  8. Path coupling and aggregate path coupling

    CERN Document Server

    Kovchegov, Yevgeniy

    2018-01-01

    This book describes and characterizes an extension to the classical path coupling method applied to statistical mechanical models, referred to as aggregate path coupling. In conjunction with large deviations estimates, the aggregate path coupling method is used to prove rapid mixing of Glauber dynamics for a large class of statistical mechanical models, including models that exhibit discontinuous phase transitions which have traditionally been more difficult to analyze rigorously. The book shows how the parameter regions for rapid mixing for several classes of statistical mechanical models are derived using the aggregate path coupling method.

  9. Chimera states: Effects of different coupling topologies

    Science.gov (United States)

    Bera, Bidesh K.; Majhi, Soumen; Ghosh, Dibakar; Perc, Matjaž

    2017-04-01

    Collective behavior among coupled dynamical units can emerge in various forms as a result of different coupling topologies as well as different types of coupling functions. Chimera states have recently received ample attention as a fascinating manifestation of collective behavior, in particular describing a symmetry breaking spatiotemporal pattern where synchronized and desynchronized states coexist in a network of coupled oscillators. In this perspective, we review the emergence of different chimera states, focusing on the effects of different coupling topologies that describe the interaction network connecting the oscillators. We cover chimera states that emerge in local, nonlocal and global coupling topologies, as well as in modular, temporal and multilayer networks. We also provide an outline of challenges and directions for future research.

  10. Anderson Hamiltonian description of the experimental electronic structure and magnetic interactions of copper oxide superconductors

    International Nuclear Information System (INIS)

    Shen, Z.; Allen, J.W.; Yeh, J.J.

    1987-01-01

    We describe valence-band and core-level photoemission data for copper oxide superconductors using the Anderson Hamiltonian applied to an impurity-cluster configuration-interaction model. We obtain experimental values of the parameters of the model the copper X oxygen charge transfer energy Δ∼0.4 eV, the d-d Coulomb interaction U∼6 eV, and the ligand-d hybridization T∼2.4 eV. Using these parameters, we evaluate the linear Cu-O-Cu superexchange interaction J and find it is dominated by the charge-transfer fluctuations. The magnitude obtained for J is much larger than typical Neel temperatures of these materials, and is somewhat larger than that estimated from applying the resonating-valence-bond picture to La 2 CuO 4 . We point out that for Δ >Δ, the charge-transfer degrees of freedom, and the lattice aspects of the Anderson lattice Hamiltonian, should not be neglected in constructing models for the high-T/sub c/ superconductivity. We also emphasize our resonant-photoemission result that the very small density of states at or near the Fermi level in all these materials has a substantial contribution from Cu 3d states, suggesting their importance for the superconductivity. We report other details of the resonant-photoemission data involving La and Ba states in the materials containing these elements

  11. Bunched soliton states in weakly coupled sine-Gordon systems

    DEFF Research Database (Denmark)

    Grønbech-Jensen, N.; Samuelsen, Mogens Rugholm; Lomdahl, P. S.

    1990-01-01

    The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results.......The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results....

  12. Typology of Couples Entering Alcohol Behavioral Couple Therapy: An Empirical Approach and Test of Predictive Validity on Treatment Response.

    Science.gov (United States)

    Ladd, Benjamin O; McCrady, Barbara S

    2016-01-01

    This study aimed to examine whether classification of couples in which one partner has an alcohol problem is similar to that reported in the general couples literature. Typologies of couples seeking alcohol behavioral couple therapy (ABCT) were developed via hierarchical cluster analysis using behavioral codes of couple interactions during their first ABCT session. Four couples types based on in-session behavior were established reliably, labeled avoider, validator, hostile, and ambivalent-detached. These couple types resembled couples types found in previous research. Couple type was associated with baseline relationship satisfaction, but not alcohol use. Results suggest heterogeneity in couples with alcohol problems presenting to treatment; further study is needed to investigate the function of alcohol within these different types. © 2015 American Association for Marriage and Family Therapy.

  13. Nuclear physics from strong coupling QCD

    CERN Document Server

    Fromm, Michael

    2009-01-01

    The strong coupling limit (beta_gauge = 0) of QCD offers a number of remarkable research possibilities, of course at the price of large lattice artifacts. Here, we determine the complete phase diagram as a function of temperature T and baryon chemical potential mu_B, for one flavor of staggered fermions in the chiral limit, with emphasis on the determination of a tricritical point and on the T ~ 0 transition to nuclear matter. The latter is known to happen for mu_B substantially below the baryon mass, indicating strong nuclear interactions in QCD at infinite gauge coupling. This leads us to studying the properties of nuclear matter from first principles. We determine the nucleon-nucleon potential in the strong coupling limit, as well as masses m_A of nuclei as a function of their atomic number A. Finally, we clarify the origin of nuclear interactions at strong coupling, which turns out to be a steric effect.

  14. Interactions of light gravitinos

    International Nuclear Information System (INIS)

    Clark, T.E.; Lee, T.; Love, S.T.; Wu, G.

    1998-01-01

    In models of spontaneously broken supersymmetry, certain light gravitino processes are governed by the coupling of their Goldstino components. The rules for constructing SUSY and gauge invariant actions involving the Goldstino couplings to matter and gauge fields are presented. The explicit operator construction is found to be at variance with some previously reported claims. A phenomenological consequence arising from light gravitino interactions in supernova is reexamined and scrutinized. copyright 1998 The American Physical Society

  15. The Harmonically Coupled 2-Beam FEL

    CERN Document Server

    McNeil, Brian W J

    2004-01-01

    A 1-D model of a 2-beam Free Electron Laser amplifier is presented. The two co-propagating electron beams have different energies, chosen so that the fundamental resonant FEL interaction of the higher energy beam is at an harmonic of the lower energy beam. In this way, a coupling between the FEL interactions of the two beams occurs via the harmonic components of the electron bunching and radiation emission of the lower energy interaction. Such resonantly coupled FEL interactions may offer potential benefits over existing single beam FEL schemes. A simple example is presented where the lower energy FEL interaction only is seeded with radiation at its fundamental resonant wavelength. It is predicted that the coherence properties of this seed field are transfered via the resonantly coupled FEL interaction to the un-seeded higher energy FEL interaction, thereby improving its coherence properties over that of a SASE interaction alone. This method may offer an alternative seeding scheme for FELs operating in the XU...

  16. Strong Coupling between Plasmons and Organic Semiconductors

    Directory of Open Access Journals (Sweden)

    Joel Bellessa

    2014-05-01

    Full Text Available In this paper we describe the properties of organic material in strong coupling with plasmon, mainly based on our work in this field of research. The strong coupling modifies the optical transitions of the structure, and occurs when the interaction between molecules and plasmon prevails on the damping of the system. We describe the dispersion relation of different plasmonic systems, delocalized and localized plasmon, coupled to aggregated dyes and the typical properties of these systems in strong coupling. The modification of the dye emission is also studied. In the second part, the effect of the microscopic structure of the organics, which can be seen as a disordered film, is described. As the different molecules couple to the same plasmon mode, an extended coherent state on several microns is observed.

  17. Strong Coupling Corrections in Quantum Thermodynamics

    Science.gov (United States)

    Perarnau-Llobet, M.; Wilming, H.; Riera, A.; Gallego, R.; Eisert, J.

    2018-03-01

    Quantum systems strongly coupled to many-body systems equilibrate to the reduced state of a global thermal state, deviating from the local thermal state of the system as it occurs in the weak-coupling limit. Taking this insight as a starting point, we study the thermodynamics of systems strongly coupled to thermal baths. First, we provide strong-coupling corrections to the second law applicable to general systems in three of its different readings: As a statement of maximal extractable work, on heat dissipation, and bound to the Carnot efficiency. These corrections become relevant for small quantum systems and vanish in first order in the interaction strength. We then move to the question of power of heat engines, obtaining a bound on the power enhancement due to strong coupling. Our results are exemplified on the paradigmatic non-Markovian quantum Brownian motion.

  18. Interacting dark sector with transversal interaction

    Energy Technology Data Exchange (ETDEWEB)

    Chimento, Luis P.; Richarte, Martín G. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Pabellón I, Buenos Aires 1428 (Argentina)

    2015-03-26

    We investigate the interacting dark sector composed of dark matter, dark energy, and dark radiation for a spatially flat Friedmann-Robertson-Walker (FRW) background by introducing a three-dimensional internal space spanned by the interaction vector Q and solve the source equation for a linear transversal interaction. Then, we explore a realistic model with dark matter coupled to a scalar field plus a decoupled radiation term, analyze the amount of dark energy in the radiation era and find that our model is consistent with the recent measurements of cosmic microwave background anisotropy coming from Planck along with the future constraints achievable by CMBPol experiment.

  19. Electromagnetic clutches and couplings

    CERN Document Server

    Vorob'Yeva, T M; Fry, D W; Higinbotham, W

    2013-01-01

    Electromagnetic Clutches and Couplings contains a detailed description of U.S.S.R. electromagnetic friction clutches, magnetic couplings, and magnetic particle couplings. This book is divided into four chapters. The first chapter discusses the design and construction of magnetic (solenoid-operated) couplings, which are very quick-acting devices and used in low power high-speed servo-systems. Chapter 2 describes the possible fields of application, design, construction, and utilization of magnetic particle couplings. The aspects of construction, design, and utilization of induction clutches (sli

  20. Optical Signatures of Coupled Quantum Dots

    Science.gov (United States)

    Stinaff, E. A.; Scheibner, M.; Bracker, A. S.; Ponomarev, I. V.; Korenev, V. L.; Ware, M. E.; Doty, M. F.; Reinecke, T. L.; Gammon, D.

    2006-02-01

    An asymmetric pair of coupled InAs quantum dots is tuned into resonance by applying an electric field so that a single hole forms a coherent molecular wave function. The optical spectrum shows a rich pattern of level anticrossings and crossings that can be understood as a superposition of charge and spin configurations of the two dots. Coulomb interactions shift the molecular resonance of the optically excited state (charged exciton) with respect to the ground state (single charge), enabling light-induced coupling of the quantum dots. This result demonstrates the possibility of optically coupling quantum dots for application in quantum information processing.

  1. Electroweak interactions

    International Nuclear Information System (INIS)

    Bjorken, J.D.

    1980-10-01

    A point of view of the electroweak interaction is presented. It begins phenomenologically and moves in stages toward the conventional gauge theory formalism containing elementary scalar Higgs-fields and then beyond. The purpose in so doing is that the success of the standard SU(2) x U(1) theory in accounting for low energy phenomena need not automatically imply success at high energies. It is deemed unlikely by most theorists that the predicted W +- or Z 0 does not exist or does not have the mass and/or couplings anticipated in the standard model. However, the odds that the standard predictions will work are not 100%. Therefore there is some reason to look at the subject as one would were he forced by a wrong experimental outcome - to go back to fundamentals and ascertain what is the minimal amount of theory necessary to account for the data

  2. Coherence protection in coupled quantum systems

    Science.gov (United States)

    Cammack, H. M.; Kirton, P.; Stace, T. M.; Eastham, P. R.; Keeling, J.; Lovett, B. W.

    2018-02-01

    The interaction of a quantum system with its environment causes decoherence, setting a fundamental limit on its suitability for quantum information processing. However, we show that if the system consists of coupled parts with different internal energy scales then the interaction of one part with a thermal bath need not lead to loss of coherence from the other. Remarkably, we find that the protected part can remain coherent for longer when the coupling to the bath becomes stronger or the temperature is raised. Our theory will enable the design of decoherence-resistant hybrid quantum computers.

  3. Bright solitons in coupled defocusing NLS equation supported by coupling: Application to Bose-Einstein condensation

    International Nuclear Information System (INIS)

    Adhikari, Sadhan K.

    2005-01-01

    We demonstrate the formation of bright solitons in coupled self-defocusing nonlinear Schroedinger (NLS) equation supported by attractive coupling. As an application we use a time-dependent dynamical mean-field model to study the formation of stable bright solitons in two-component repulsive Bose-Einstein condensates (BECs) supported by interspecies attraction in a quasi one-dimensional geometry. When all interactions are repulsive, there cannot be bright solitons. However, bright solitons can be formed in two-component repulsive BECs for a sufficiently attractive interspecies interaction, which induces an attractive effective interaction among bosons of same type

  4. EPR of exchange coupled systems

    CERN Document Server

    Bencini, Alessandro

    2012-01-01

    From chemistry to solid state physics to biology, the applications of Electron Paramagnetic Resonance (EPR) are relevant to many areas. This unified treatment is based on the spin Hamiltonian approach and makes extensive use of irreducible tensor techniques to analyze systems in which two or more spins are magnetically coupled. This edition contains a new Introduction by coauthor Dante Gatteschi, a pioneer and scholar of molecular magnetism.The first two chapters review the foundations of exchange interactions, followed by examinations of the spectra of pairs and clusters, relaxation in oligon

  5. Structure & Coupling of Semiotic Sets

    Science.gov (United States)

    Orsucci, Franco; Giuliani, Alessandro; Zbilut, Joseph

    2004-12-01

    We investigated the informational structure of written texts (also in the form of speech transcriptions) using Recurrence Quantification Analysis (RQA). RQA technique provides a quantitative description of text sequences at the orthographic level in terms of structuring, and may be useful for a variety of linguistics-related studies. We used RQA to measure differences in linguistic samples from different subjects. They were divided in subgroups based on personality and culture differences. We used RQA and KRQA (Cross Recurrence) to measure the coupling and synchronization during the conversation (semiotic interaction) of different subjects. We discuss results both for the improvement of methodology and some general implications for neurocognitive science.

  6. Asymmetric interpersonal coupling in a cyclic sports-related movement task

    NARCIS (Netherlands)

    Meerhoff, Rens; De Poel, Harjo J.

    In interactive sports, teammates and/or opponents mutually tune their behavior. Expert performance thus implies certain interactive abilities, which critically depend on perceptual coupling. To illustrate this assertion, we examined the coordination dynamics with asymmetric interaction of dyads

  7. Coupled channels in the different models

    International Nuclear Information System (INIS)

    Badalyan, A.M.; Polikarpov, M.I.; Simonov, Yu.A.

    1980-01-01

    Description of the multichannel phenomena due to channel coupling is considered. The different methods: the relativistic Logunov-Tavkhelidze-Blankenbecler-Sugar equations, the Schroedinger equation with the separable potentials and the many-channel N-D method are discussed. The particular emphasis is made on the dependence of pole trajectories and cross sections on the parameters of the coupled channel (CC) pole interaction. In detail the properties of the N anti N interaction with annihilation are taken into account. Elastic, charge exchange and annihilation cross sections are calculated in the 0-100 MeV energy range. The peaks in all cross sections at the threshold are due to the CC poles in the L=0 waves. The position of the 16 poles in different states for the case of no CC interaction and the standard CC interaction is presented

  8. Coupling Integrable Couplings of an Equation Hierarchy

    International Nuclear Information System (INIS)

    Wang Hui; Xia Tie-Cheng

    2013-01-01

    Based on a kind of Lie algebra G proposed by Zhang, one isospectral problem is designed. Under the framework of zero curvature equation, a new kind of integrable coupling of an equation hierarchy is generated using the methods proposed by Ma and Gao. With the help of variational identity, we get the Hamiltonian structure of the hierarchy. (general)

  9. A computational study of magnetic exchange interactions of 3d and 4f electrons in Ti-Ce co-doped AlN

    Energy Technology Data Exchange (ETDEWEB)

    Majid, Abdul, E-mail: abdulmajid40@yahoo.com [Department of Physics, University of Gujrat, Gujrat (Pakistan); Department of Adaptive Machine Systems, Osaka University, Osaka (Japan); Azmat, Mian [Department of Physics, University of Gujrat, Gujrat (Pakistan); Rana, Usman Ali; Khan, Salah Ud-Din [Sustainable Energy Technologies Center, College of Engineering, King Saud University, PO-Box 800, Riyadh 11421 (Saudi Arabia); Alzahrani, Eman [Department of Chemistry, Faculty of Science, Taif University, 888 Taif (Saudi Arabia)

    2016-08-15

    To investigate the nature of 3d-4f exchange interactions in III-Nitride semiconductors, Ti-Ce co-doped AlN were studied using first principles calculations. The calculations were performed using supercell approach with varying dopant concentration and different inter-dopant separation. The configuration with dopant located as nearest neighbor distance and diluted concentration of 3.125% was found most stable. The results exhibited prominent evidence of 3d-4f-5d strong hybridization suggesting 3d-4f direct exchange interactions which may play valuable role to exploit the system as high Curie temperature ferromagnetic semiconductors for use in spintronics. Moreover, metal to metal charge transfer was also observed in the materials which may be exploited for their use in electrochemical applications. The 4f-5d and 3d-5d hybridizations were observed that predicts excellent luminescence phenomena in the materials. The presence of impurity related deep intermediate bands suggest applications of the materials in opto-electronic and spintronics devices. - Highlights: • Double exchange interaction in Ti:AlN. • Impurity induced narrowing of band gap. • Superexchange interaction in Ce:AlN. • 3d-4f exchange interaction between Ti-3d and Ce-4f states. • High Curie temperature n-type ferromagnetic semiconductors.

  10. A computational study of magnetic exchange interactions of 3d and 4f electrons in Ti-Ce co-doped AlN

    International Nuclear Information System (INIS)

    Majid, Abdul; Azmat, Mian; Rana, Usman Ali; Khan, Salah Ud-Din; Alzahrani, Eman

    2016-01-01

    To investigate the nature of 3d-4f exchange interactions in III-Nitride semiconductors, Ti-Ce co-doped AlN were studied using first principles calculations. The calculations were performed using supercell approach with varying dopant concentration and different inter-dopant separation. The configuration with dopant located as nearest neighbor distance and diluted concentration of 3.125% was found most stable. The results exhibited prominent evidence of 3d-4f-5d strong hybridization suggesting 3d-4f direct exchange interactions which may play valuable role to exploit the system as high Curie temperature ferromagnetic semiconductors for use in spintronics. Moreover, metal to metal charge transfer was also observed in the materials which may be exploited for their use in electrochemical applications. The 4f-5d and 3d-5d hybridizations were observed that predicts excellent luminescence phenomena in the materials. The presence of impurity related deep intermediate bands suggest applications of the materials in opto-electronic and spintronics devices. - Highlights: • Double exchange interaction in Ti:AlN. • Impurity induced narrowing of band gap. • Superexchange interaction in Ce:AlN. • 3d-4f exchange interaction between Ti-3d and Ce-4f states. • High Curie temperature n-type ferromagnetic semiconductors.

  11. Chirality, nongauge couplings and compositeness

    International Nuclear Information System (INIS)

    Suzuki, Mahiko

    1985-01-01

    We study from a phenomenological viewpoint what constraints exist on a possible scale of compositeness for W, Z, leptons, and quarks. A few critical arguments are presented about excited fermions and spinless partners of W and Z. It is argued that irrespective of a compositeness scale, the coupling of an excited fermion to a ground state light fermion is likely to be maximally parity violating. Besides chirality breaking interactions of light fermions, gauge noninvariant, dimensionless, unrenormalizable couplings are specially interesting in many classes of composite theories. The deviation of the W magnetic moment from the standard theory (g = 2) is such an example. We relate the ''g-2'' of W to a compositeness scale through an unitarity argument and make a guess on its effect on the muon g-2 for a given compositeness scale. The present experimental data on the W-Z mass ratio is already accurate enough to indicate that if a compositeness scale is larger than 0(1 TeV), gauge noninvariant couplings of W and Z should be negligibly small and a composite theory is hardly distinguishable from an elementary particle theory at the electroweak energy scale (≅ 250 GeV). However, a compositeness scale close to the electroweak scale can not be ruled out for W and Z at present. (author)

  12. Magnetoelectric coupling in layered LSMO/PZT nanostructures

    International Nuclear Information System (INIS)

    Leufke, Philipp M.

    2014-01-01

    Multiferroic thin film composites with electric field-effect driven magnetoelectric (ME) coupling offer the possibility to reversibly tune magnetic properties in materials intended for device applications. The structural and functional versatility of such artificial heterostructures makes them attractive not only for various data processing, storage and sensor applications but also for studying the fundamental ME coupling mechanisms. La 1-x Sr x MnO 3 (LSMO)/PbZr y Ti 1-y O 3 (PZT) is an ideal choice for such a composite, combining the unrivaled ferroelectric (FE) properties of PZT with the multiple electronic and magnetic phenomena exhibited by the mixed valency manganite LSMO. The main physical feature used in realization of the LSMO/PZT ME composites is a striking sensitivity of LSMO magnetism to the charge carrier density. Here, the low-doping region is of particular interest, where the competition between the fundamental magnetic coupling mechanisms, Double-Exchange (DE) versus Superexchange (SE), is most distinctive. In the present work an unconventional sputtering technique - the Large-Distance Magnetron Sputtering (LDMS) method - has been established, which allowed for epitaxial deposition of these heterostructures with highest crystallinity and markedly smooth interfaces, necessary for effective field-effect control of magnetism. The large target-substrate distance effectively suppressed the destructive oxygen ion bombardment, inherently connected with oxide sputtering, and yielded an outstanding lateral uniformity of the film stack. The latter was vital for the fabrication of large capacitor structures of several square millimeter area that were required for detecting the ME coupling in a Superconductive Quantum Interference Device (SQUID) magnetometer. The growth of LSMO on various single crystalline substrates was mastered by exploring a vast deposition parameter space, encompassing Radio Frequency (RF) and Direct Current (DC) sputtering. Commensurately

  13. Magnetoelectric coupling in layered LSMO/PZT nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Leufke, Philipp M.

    2014-01-29

    Multiferroic thin film composites with electric field-effect driven magnetoelectric (ME) coupling offer the possibility to reversibly tune magnetic properties in materials intended for device applications. The structural and functional versatility of such artificial heterostructures makes them attractive not only for various data processing, storage and sensor applications but also for studying the fundamental ME coupling mechanisms. La{sub 1-x}Sr{sub x}MnO{sub 3} (LSMO)/PbZr{sub y}Ti{sub 1-y}O{sub 3} (PZT) is an ideal choice for such a composite, combining the unrivaled ferroelectric (FE) properties of PZT with the multiple electronic and magnetic phenomena exhibited by the mixed valency manganite LSMO. The main physical feature used in realization of the LSMO/PZT ME composites is a striking sensitivity of LSMO magnetism to the charge carrier density. Here, the low-doping region is of particular interest, where the competition between the fundamental magnetic coupling mechanisms, Double-Exchange (DE) versus Superexchange (SE), is most distinctive. In the present work an unconventional sputtering technique - the Large-Distance Magnetron Sputtering (LDMS) method - has been established, which allowed for epitaxial deposition of these heterostructures with highest crystallinity and markedly smooth interfaces, necessary for effective field-effect control of magnetism. The large target-substrate distance effectively suppressed the destructive oxygen ion bombardment, inherently connected with oxide sputtering, and yielded an outstanding lateral uniformity of the film stack. The latter was vital for the fabrication of large capacitor structures of several square millimeter area that were required for detecting the ME coupling in a Superconductive Quantum Interference Device (SQUID) magnetometer. The growth of LSMO on various single crystalline substrates was mastered by exploring a vast deposition parameter space, encompassing Radio Frequency (RF) and Direct Current (DC

  14. Interacting adiabatic quantum motor

    Science.gov (United States)

    Bruch, Anton; Kusminskiy, Silvia Viola; Refael, Gil; von Oppen, Felix

    2018-05-01

    We present a field-theoretic treatment of an adiabatic quantum motor. We explicitly discuss a motor called the Thouless motor which is based on a Thouless pump operating in reverse. When a sliding periodic potential is considered to be the motor degree of freedom, a bias voltage applied to the electron channel sets the motor in motion. We investigate a Thouless motor whose electron channel is modeled as a Luttinger liquid. Interactions increase the gap opened by the periodic potential. For an infinite Luttinger liquid the coupling-induced friction is enhanced by electron-electron interactions. When the Luttinger liquid is ultimately coupled to Fermi liquid reservoirs, the dissipation reduces to its value for a noninteracting electron system for a constant motor velocity. Our results can also be applied to a motor based on a nanomagnet coupled to a quantum spin Hall edge.

  15. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    Rosenberg, Marelene

    2005-01-01

    Our theoretical research on dust-plasma interactions has concentrated on three main areas: (a)studies of grain charging and applications; (b) waves and instabilities in weakly correlated dusty plasma with applications to space and laboratory plasmas; (c) waves in strongly coupled dusty plasmas.

  16. Translation-coupling systems

    Science.gov (United States)

    Pfleger, Brian; Mendez-Perez, Daniel

    2013-11-05

    Disclosed are systems and methods for coupling translation of a target gene to a detectable response gene. A version of the invention includes a translation-coupling cassette. The translation-coupling cassette includes a target gene, a response gene, a response-gene translation control element, and a secondary structure-forming sequence that reversibly forms a secondary structure masking the response-gene translation control element. Masking of the response-gene translation control element inhibits translation of the response gene. Full translation of the target gene results in unfolding of the secondary structure and consequent translation of the response gene. Translation of the target gene is determined by detecting presence of the response-gene protein product. The invention further includes RNA transcripts of the translation-coupling cassettes, vectors comprising the translation-coupling cassettes, hosts comprising the translation-coupling cassettes, methods of using the translation-coupling cassettes, and gene products produced with the translation-coupling cassettes.

  17. Chameleons with field-dependent couplings

    International Nuclear Information System (INIS)

    Brax, Philippe; Bruck, Carsten van de; Mota, David F.; Winther, Hans A.; Nunes, Nelson J.

    2010-01-01

    Certain scalar-tensor theories exhibit the so-called chameleon mechanism, whereby observational signatures of scalar fields are hidden by a combination of self-interactions and interactions with ambient matter. Not all scalar-tensor theories exhibit such a chameleon mechanism, which has been originally found in models with inverse power runaway potentials and field-independent couplings to matter. In this paper we investigate field theories with field-dependent couplings and a power-law potential for the scalar field. We show that the theory indeed is a chameleon field theory. We find the thin-shell solution for a spherical body and investigate the consequences for Eoet-Wash experiments, fifth-force searches and Casimir-force experiments. Requiring that the scalar field evades gravitational tests, we find that the coupling is sensitive to a mass scale which is of order of the Hubble scale today.

  18. Mesoscopic quantum emitters coupled to plasmonic nanostructures

    DEFF Research Database (Denmark)

    Andersen, Mads Lykke

    for the spontaneous emission of mesoscopic quantum emitters is developed. The light-matter interaction is in this model modied beyond the dipole expectancy and found to both suppress and enhance the coupling to plasmonic modes in excellent agreement with our measurements. We demonstrate that this mesoscopic effect......This thesis reports research on quantum dots coupled to dielectric and plasmonic nano-structures by way of nano-structure fabrication, optical measurements, and theoretical modeling. To study light-matter interaction, plasmonic gap waveguides with nanometer dimensions as well as samples for studies...... to allow for e- cient plasmon-based single-photon sources. Theoretical studies of coupling and propagation properties of plasmonic waveguides reveal that a high-refractive index of the medium surrounding the emitter, e.g. nGaAs = 3.5, limits the realizability of ecient plasmon-based single-photon sources...

  19. Reintegration Difficulty of Military Couples Following Deployment

    Science.gov (United States)

    2017-07-01

    reintegration. Communication and Generalized Anxiety The emotional cycle of deployment model provides a descrip- tive framework for understanding the...counseling. Thus, communication can have a reciprocal influence on the very appraisals and emotions that motivate interaction in the first place. Communication...of service members back into family life after deployment can be extremely challenging for military couples. Understanding the factors that

  20. Coupling effect on the Berry phase

    Directory of Open Access Journals (Sweden)

    Lijing Tian

    2016-11-01

    Full Text Available The Berry phase has universal applications in various fields. Here, we explore the coupling effect on the Berry phase of a two-level system adiabatically driven by a rotating classical field and interacting with a single quantized mode. Our simulations clearly reveal that the Berry phase change is quadratic proportional to the coupling constant if it is less than the level spacing between neighboring instantaneous eigenstates. Remarkably, if the nearest neighbouring level spacing is comparable with the coupling constant, this simple quadratic dependence is lost. Around this resonance, the Berry phase can be significantly tuned by slightly adjusting the parameters, such as the coupling constant, the frequency of the quantized mode, and the transition frequency. These numerical results, agreeing well with the perturbation theory calculations, provide an alternative approach to tune the Berry phase near the resonance, which is useful in quantum information science, i.e. designing quantum logic gates.

  1. Multi-disciplinary coupling for integrated design of propulsion systems

    Science.gov (United States)

    Chamis, C. C.; Singhal, S. N.

    1993-01-01

    Effective computational simulation procedures are described for modeling the inherent multi-disciplinary interactions for determining the true response of propulsion systems. Results are presented for propulsion system responses including multi-discipline coupling effects via (1) coupled multi-discipline tailoring, (2) an integrated system of multidisciplinary simulators, (3) coupled material-behavior/fabrication-process tailoring, (4) sensitivities using a probabilistic simulator, and (5) coupled materials/structures/fracture/probabilistic behavior simulator. The results show that the best designs can be determined if the analysis/tailoring methods account for the multi-disciplinary coupling effects. The coupling across disciplines can be used to develop an integrated interactive multi-discipline numerical propulsion system simulator.

  2. Layered vanadyl (IV) nitroprusside: Magnetic interaction through a network of hydrogen bonds

    Energy Technology Data Exchange (ETDEWEB)

    Gil, D.M. [Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Lorenzo 456, T4000CAN San Miguel de Tucumán (Argentina); Osiry, H. [Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, Instituto Politécnico Nacional, México (Mexico); Pomiro, F.; Varetti, E.L. [CEQUINOR (CONICET-UNLP), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 47 and 115, 1900, La Plata (Argentina); Carbonio, R.E. [INFIQC – CONICET, Departamento de Físico Química, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre esq, Medina Allende, Ciudad Universitaria, X5000HUA Córdoba (Argentina); Alejandro, R.R. [Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, Instituto Politécnico Nacional, México (Mexico); Ben Altabef, A. [INQUINOA-UNT-CONICET, Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Lorenzo 456, T4000CAN San Miguel de Tucumán (Argentina); and others

    2016-07-15

    The hydrogen bond and π-π stacking are two non-covalent interactions able to support cooperative magnetic ordering between paramagnetic centers. This contribution reports the crystal structure and related magnetic properties for VO[Fe(CN){sub 5}NO]·2H{sub 2}O, which has a layered structure. This solid crystallizes with an orthorhombic unit cell, in the Pna2{sub 1} space group, with cell parameters a=14.1804(2), b=10.4935(1), c=7.1722(8) Å and four molecules per unit cell (Z=4). Its crystal structure was solved and refined from powder X-ray diffraction data. Neighboring layers remain linked through a network of hydrogen bonds involving a water molecule coordinated to the axial position for the V atom and the unbridged axial NO and CN ligands. An uncoordinated water molecule is found forming a triple bridge between these last two ligands and the coordinated water molecule. The magnetic measurements, recorded down to 2 K, shows a ferromagnetic interaction between V atoms located at neighboring layers, with a Curie-Weiss constant of 3.14 K. Such ferromagnetic behavior was interpreted as resulting from a superexchange interaction through the network of strong OH····O{sub H2O}, OH····N{sub CN}, and OH····O{sub NO} hydrogen bonds that connects neighboring layers. The interaction within the layer must be of antiferromagnetic nature and it was detected close to 2 K. - Graphical abstract: Coordination environment for the metals in vanadyl (II) nitroprusside dihydrate. Display Omitted - Highlights: • Crystal structure of vanadyl nitroprusside dehydrate. • Network of hydrogen bonds. • Magnetic interactions through a network of hydrogen bonds. • Layered transition metal nitroprussides.

  3. Superconductivity induced by interfacial coupling to magnons

    Science.gov (United States)

    Rohling, Niklas; Fjærbu, Eirik Løhaugen; Brataas, Arne

    2018-03-01

    We consider a thin normal metal sandwiched between two ferromagnetic insulators. At the interfaces, the exchange coupling causes electrons within the metal to interact with magnons in the insulators. This electron-magnon interaction induces electron-electron interactions, which in turn can result in p -wave superconductivity. We solve the gap equation numerically and estimate the critical temperature. In yttrium iron garnet (YIG)-Au-YIG trilayers, superconductivity sets in at temperatures somewhere in the interval between 1 and 10 K. EuO-Au-EuO trilayers require a lower temperature, in the range from 0.01 to 1 K.

  4. Plastics pipe couplings

    International Nuclear Information System (INIS)

    Glover, J.B.

    1980-07-01

    A method is described of making a pipe coupling of the type comprising a plastics socket and a resilient annular sealing member secured in the mouth thereof, in which the material of at least one component of the coupling is subjected to irradiation with high energy radiation whereby the material is caused to undergo cross-linking. As examples, the coupling may comprise a polyethylene or plasticised PVC socket the material of which is subjected to irradiation, and the sealing member may be moulded from a thermoplastic elastomer which is subjected to irradiation. (U.K.)

  5. Dynamics of multi-frequency oscillator ensembles with resonant coupling

    Science.gov (United States)

    Lück, S.; Pikovsky, A.

    2011-07-01

    We study dynamics of populations of resonantly coupled oscillators having different frequencies. Starting from the coupled van der Pol equations we derive the Kuramoto-type phase model for the situation, where the natural frequencies of two interacting subpopulations are in relation 2:1. Depending on the parameter of coupling, ensembles can demonstrate fully synchronous clusters, partial synchrony (only one subpopulation synchronizes), or asynchrony in both subpopulations. Theoretical description of the dynamics based on the Watanabe-Strogatz approach is developed.

  6. Couple Leisure Time: Building Bonds Early in Marriage Through Leisure

    OpenAIRE

    Chavez, Joy Lynne

    2015-01-01

    Participation in couple leisure is related to marital satisfaction as well as lower divorce rates; however, Americans seem to have less time available to participate in couple leisure and may have a harder time attaining role balance. There is currently limited research about how role balance may affect leisure as well as how couples manage to balance their leisure time with their other responsibilities, ensuring they have time to spend together in high interaction leisure. We also know very ...

  7. Density-dependent coupling constants and charge symmetry breaking

    International Nuclear Information System (INIS)

    Barreiro, L.A.

    2001-01-01

    The effect of the medium in the coupling constants implicate in a charge symmetry breaking on nuclear interactions. The amount of energy due to this modification can explain the Nolen-Schiffer anomaly. (author)

  8. Electrical-thermal coupling of induction machine for improved ...

    African Journals Online (AJOL)

    Electrical-thermal coupling of induction machine for improved thermal performance. ... Nigerian Journal of Technology ... The interaction of its electrical and mechanical parts leads to an increase in temperature which if not properly monitored ...

  9. Bunched soliton states in weakly coupled sine-Gordon systems

    International Nuclear Information System (INIS)

    Gronbech-Jensen, N.; Samuelsen, M.R.; Lomdahl, P.S.; Blackburn, J.A.

    1990-01-01

    The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results

  10. Spin-orbit and spin-lattice coupling

    International Nuclear Information System (INIS)

    Bauer, Gerrit E.W.; Ziman, Timothy; Mori, Michiyasu

    2014-01-01

    We pursued theoretical research on the coupling of electron spins in the condensed matter to the lattice as mediated by the spin-orbit interaction with special focus on the spin and anomalous Hall effects. (author)

  11. The Story of Closely and Loosely Coupled Organisations.

    Science.gov (United States)

    Plowman, Travis S.

    1998-01-01

    Examines five types of collegiate organizations (collegial, bureaucratic, political, anarchical, cybernetic) in terms of their interactiveness within closely and loosely coupled organizations. The terminology of closely and loosely coupled organizations is examined and existing definitions are refined. Examples are drawn from contemporary…

  12. Synchronization and suppression of chaos in non-locally coupled ...

    Indian Academy of Sciences (India)

    Abstract. We considered coupled map lattices with long-range interactions to study the spatiotemporal behaviour of spatially extended dynamical systems. Coupled map lattices have been intensively investigated as models to understand many spatiotemporal phenomena observed in extended system, and consequently ...

  13. Time-dependent density functional theory (TD-DFT) coupled with reference interaction site model self-consistent field explicitly including spatial electron density distribution (RISM-SCF-SEDD)

    Energy Technology Data Exchange (ETDEWEB)

    Yokogawa, D., E-mail: d.yokogawa@chem.nagoya-u.ac.jp [Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya 464-8602 (Japan)

    2016-09-07

    Theoretical approach to design bright bio-imaging molecules is one of the most progressing ones. However, because of the system size and computational accuracy, the number of theoretical studies is limited to our knowledge. To overcome the difficulties, we developed a new method based on reference interaction site model self-consistent field explicitly including spatial electron density distribution and time-dependent density functional theory. We applied it to the calculation of indole and 5-cyanoindole at ground and excited states in gas and solution phases. The changes in the optimized geometries were clearly explained with resonance structures and the Stokes shift was correctly reproduced.

  14. Mode coupling in spin torque oscillators

    International Nuclear Information System (INIS)

    Zhang, Steven S.-L.; Zhou, Yan; Li, Dong; Heinonen, Olle

    2016-01-01

    A number of recent experimental works have shown that the dynamics of a single spin torque oscillator can exhibit complex behavior that stems from interactions between two or more modes of the oscillator, such as observed mode-hopping or mode coexistence. There has been some initial work indicating how the theory for a single-mode (macro-spin) spin torque oscillator should be generalized to include several modes and the interactions between them. In the present work, we rigorously derive such a theory starting with the Landau–Lifshitz–Gilbert equation for magnetization dynamics by expanding up to third-order terms in deviation from equilibrium. Our results show how a linear mode coupling, which is necessary for observed mode-hopping to occur, arises through coupling to a magnon bath. The acquired temperature dependence of this coupling implies that the manifold of orbits and fixed points may shift with temperature. - Highlights: • Deriving equations for coupled modes in spin torque oscillators. • Including Hamiltonian formalism and elimination of three–magnon processes. • Thermal bath of magnons central to mode coupling. • Numerical examples of circular and elliptical devices.

  15. Mode coupling in spin torque oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Steven S.-L., E-mail: ZhangShule@missouri.edu [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); Zhou, Yan, E-mail: yanzhou@hku.hk [Department of Physics, The University of Hong Kong, Hong Kong (China); Center of Theoretical and Computational Physics, University of Hong Kong, Hong Kong (China); Li, Dong, E-mail: geodesic.ld@gmail.com [Department of Physics, Centre for Nonlinear Studies, and Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China); Heinonen, Olle, E-mail: heinonen@anl.gov [Material Science Division, Argonne National Laboratory, Lemont, IL 60439 (United States); Northwestern-Argonne Institute of Science and Technology, 2145 Sheridan Road, Evanston, IL 60208 (United States); Computation Institute, The Unversity of Chicago, 5735 S Ellis Avenue, Chicago, IL 60637 (United States)

    2016-09-15

    A number of recent experimental works have shown that the dynamics of a single spin torque oscillator can exhibit complex behavior that stems from interactions between two or more modes of the oscillator, such as observed mode-hopping or mode coexistence. There has been some initial work indicating how the theory for a single-mode (macro-spin) spin torque oscillator should be generalized to include several modes and the interactions between them. In the present work, we rigorously derive such a theory starting with the Landau–Lifshitz–Gilbert equation for magnetization dynamics by expanding up to third-order terms in deviation from equilibrium. Our results show how a linear mode coupling, which is necessary for observed mode-hopping to occur, arises through coupling to a magnon bath. The acquired temperature dependence of this coupling implies that the manifold of orbits and fixed points may shift with temperature. - Highlights: • Deriving equations for coupled modes in spin torque oscillators. • Including Hamiltonian formalism and elimination of three–magnon processes. • Thermal bath of magnons central to mode coupling. • Numerical examples of circular and elliptical devices.

  16. Coupled transverse motion

    International Nuclear Information System (INIS)

    Teng, L.C.

    1989-01-01

    The magnetic field in an accelerator or a storage ring is usually so designed that the horizontal (x) and the vertical (y) motions of an ion are uncoupled. However, because of imperfections in construction and alignment, some small coupling is unavoidable. In this lecture, we discuss in a general way what is known about the behaviors of coupled motions in two degrees-of-freedom. 11 refs., 6 figs

  17. Supernovae type Ia data favour coupled phantom energy

    OpenAIRE

    Majerotto, Elisabetta; Sapone, Domenico; Amendola, Luca

    2004-01-01

    We estimate the constraints that the recent high-redshift sample of supernovae type Ia put on a phenomenological interaction between dark energy and dark matter. The interaction can be interpreted as arising from the time variation of the mass of dark matter particles. We find that the coupling correlates with the equation of state: roughly speaking, a negative coupling (in our sign convention) implies phantom energy ($w_{\\phi}

  18. Coupled uncertainty provided by a multifractal random walker

    International Nuclear Information System (INIS)

    Koohi Lai, Z.; Vasheghani Farahani, S.; Movahed, S.M.S.; Jafari, G.R.

    2015-01-01

    The aim here is to study the concept of pairing multifractality between time series possessing non-Gaussian distributions. The increasing number of rare events creates “criticality”. We show how the pairing between two series is affected by rare events, which we call “coupled criticality”. A method is proposed for studying the coupled criticality born out of the interaction between two series, using the bivariate multifractal random walk (BiMRW). This method allows studying dependence of the coupled criticality on the criticality of each individual system. This approach is applied to data sets of gold and oil markets, and inflation and unemployment. - Highlights: • The coupled criticality between two systems is modeled by the bivariate multifractal random walk. • This coupled criticality is generally directed. • This coupled criticality is inversely proportional to the criticality of either of the systems. • The coupled criticality can emerge when at least one of the systems posses a Gaussian distribution

  19. Molecular mechanism of DNA replication-coupled inactivation of the initiator protein in Escherichia coli: interaction of DnaA with the sliding clamp-loaded DNA and the sliding clamp-Hda complex.

    Science.gov (United States)

    Su'etsugu, Masayuki; Takata, Makoto; Kubota, Toshio; Matsuda, Yusaku; Katayama, Tsutomu

    2004-06-01

    In Escherichia coli, the ATP-DnaA protein initiates chromosomal replication. After the DNA polymerase III holoenzyme is loaded on to DNA, DnaA-bound ATP is hydrolysed in a manner depending on Hda protein and the DNA-loaded form of the DNA polymerase III sliding clamp subunit, which yields ADP-DnaA, an inactivated form for initiation. This regulatory DnaA-inactivation represses extra initiation events. In this study, in vitro replication intermediates and structured DNA mimicking replicational intermediates were first used to identify structural prerequisites in the process of DnaA-ATP hydrolysis. Unlike duplex DNA loaded with sliding clamps, primer RNA-DNA heteroduplexes loaded with clamps were not associated with DnaA-ATP hydrolysis, and duplex DNA provided in trans did not rescue this defect. At least 40-bp duplex DNA is competent for the DnaA-ATP hydrolysis when a single clamp was loaded. The DnaA-ATP hydrolysis was inhibited when ATP-DnaA was tightly bound to a DnaA box-bearing oligonucleotide. These results imply that the DnaA-ATP hydrolysis involves the direct interaction of ATP-DnaA with duplex DNA flanking the sliding clamp. Furthermore, Hda protein formed a stable complex with the sliding clamp. Based on these, we suggest a mechanical basis in the DnaA-inactivation that ATP-DnaA interacts with the Hda-clamp complex with the aid of DNA binding. Copyright Blackwell Publishing Limited

  20. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    Rosenberg, M.

    2010-01-01

    The objective of our theoretical research under this grant over the past 3 years was to develop new understanding in a range of topics in the physics of dust-plasma interactions, with application to space and the laboratory. We conducted studies related to the physical properties of dust, waves and instabilities in both weakly coupled and strongly coupled dusty plasmas, and innovative possible applications. A major consideration in our choice of topics was to compare theory with experiments or observations, and to motivate new experiments, which we believe is important for developing this relatively new field. Our research is summarized, with reference to our list of journal publications.