67,061 research outputs found

    Modelling and measurement accuracy enhancement of flue gas flow using neural networks

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    This paper discusses the modeling of the flue gas flow in industrial ducts and stacks using artificial neural networks (ANN's). Based upon the individual velocity and other operating conditions, an ANN model has been developed for the measurement of the volume flow rate. The model has been validated by the experiment using a case-study power plant. The results have shown that the model can largely compensate for the nonrepresentativeness of a sampling location and, as a result, the measurement accuracy of the flue gas flow can be significantly improved

    Continuous Multipartite Entangled State in Wigner Representation and the Violation of Zukowski-Brukner Inequality

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    We construct an explicit Wigner function for N-mode squeezed state. Based on a previous observation that the Wigner function describes correlations in the joint measurement of the phase-space displaced parity operator, we investigate the non-locality of multipartite entangled state by the violation of Zukowski-Brukner N-qubit Bell inequality. We find that quantum predictions for such squeezed state violate these inequalities by an amount that grows with the number N.Comment: 5 pages, rewritten version, accepted by Phys. Rev.

    Magnetic field splitting of the spin-resonance in CeCoIn5

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    Neutron scattering in strong magnetic fields is used to show the spin-resonance in superconducting CeCoIn5 (Tc=2.3 K) is a doublet. The underdamped resonance (\hbar \Gamma=0.069 \pm 0.019 meV) Zeeman splits into two modes at E_{\pm}=\hbar \Omega_{0}\pm g\mu_{B} \mu_{0}H with g=0.96 \pm 0.05. A linear extrapolation of the lower peak reaches zero energy at 11.2 \pm 0.5 T, near the critical field for the incommensurate "Q-phase" indicating that the Q-phase is a bose condensate of spin excitons.Comment: 5 pages, 4 figure

    Spin resonance in the d-wave superconductor CeCoIn5

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    Neutron scattering is used to probe antiferromagnetic spin fluctuations in the d-wave heavy fermion superconductor CeCoIn5_{5} (Tc_{c}=2.3 K). Superconductivity develops from a state with slow (Γ\hbar\Gamma=0.3 ±\pm 0.15 meV) commensurate (Q0{\bf{Q_0}}=(1/2,1/2,1/2)) antiferromagnetic spin fluctuations and nearly isotropic spin correlations. The characteristic wavevector in CeCoIn5_{5} is the same as CeIn3_{3} but differs from the incommensurate wavevector measured in antiferromagnetically ordered CeRhIn5_{5}. A sharp spin resonance (Γ<0.07\hbar\Gamma<0.07 meV) at ω\hbar \omega = 0.60 ±\pm 0.03 meV develops in the superconducting state removing spectral weight from low-energy transfers. The presence of a resonance peak is indicative of strong coupling between f-electron magnetism and superconductivity and consistent with a d-wave gap order parameter satisfying Δ(q+Q0)=Δ(q)\Delta({\bf q+Q_0})=-\Delta({\bf q}).Comment: (5 pages, 4 figures, to be published in Phys. Rev. Lett.

    Metal-insulator (fermion-boson)-crossover origin of pseudogap phase of cuprates I: anomalous heat conductivity, insulator resistivity boundary, nonlinear entropy

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    Among all experimental observations of cuprate physics, the metal-insulator-crossover (MIC), seen in the pseudogap (PG) region of the temperature-doping phase diagram of copper-oxides under a strong magnetic field, when the superconductivity is suppressed, is most likely the most intriguing one. Since it was expected that the PG-normal state for these materials, as for conventional superconductors, is conducting. This MIC, revealed in such phenomena as heat conductivity downturn, anomalous Lorentz ratio, insulator resistivity boundary, nonlinear entropy, resistivity temperature upturn, insulating ground state, nematicity- and stripe-phases and Fermi pockets, unambiguously indicates on the insulating normal state, from which the high-temperature superconductivity (HTS) appears. In the present work (article I), we discuss the MIC phenomena mentioned in the title of article. The second work (article II) will be devoted to discussion of other listed above MIC phenomena and also to interpretation of the recent observations in the hidden magnetic order and scanning tunneling microscopy (STM) experiments spin and charge fluctuations as the intra PG and HTS pair ones. We find that all these MIC (called in the literature as non-Fermi liquid) phenomena can be obtained within the Coulomb single boson and single fermion two liquid model, which we recently developed, and the MIC is a crossover of single fermions into those of single bosons. We show that this MIC originates from bosons of Coulomb two liquid model and fermions, whose origin is these bosons. At an increase of doping up to critical value or temperature up to PG boundary temperature, the boson system undegoes bosonic insulator - bosonic metal - fermionic metal transitions.Comment: 13 pages, 3 figure

    A direct link between neutrinoless double beta decay and leptogenesis in a seesaw model with S4S_4 symmetry

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    We study how leptogenesis can be implemented in a seesaw model with S4S_4 flavor symmetry, which leads to the neutrino tri-bimaximal mixing matrix and degenerate right-handed (RH) neutrino spectrum. Introducing a tiny soft S4S_4 symmetry breaking term in the RH neutrino mass matrix, we show that the flavored resonant leptogenesis can be successfully realized, which can lower the seesaw scale much so as to make it possible to probe in colliders. Even though such a tiny soft breaking term is essential for leptogenesis, it does not significantly affect the low energy observables. We also investigate how the effective light neutrino mass | | associated with neutrinoless double beta decay can be predicted along with the neutrino mass hierarchies by imposing experimental data of low-energy observables. We find a direct link between leptogenesis and neutrinoless double beta decay characterized by || through a high energy CP phase ϕ\phi, which is correlated with low energy Majorana CP phases. It is shown that our predictions of || for some fixed parameters of high energy physics can be constrained by the current observation of baryon asymmetry.Comment: 9 pages, 6 figures, references added, accepted in Phy.Rev.

    Domain growth and freezing on a triangular lattice

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    We have performed Monte Carlo simulations of domain growth at zero temperature of a lattice gas with nearest-neighbor repulsive interactions on a triangular lattice. Kawasaki dynamics were used with a fractional surface coverage of one-third. We studied both the case in which the second-nearest-neighbor interaction is attractive and the case in which it is zero. The effect of increasing the range of allowed hops from nearest neighbor to third nearest neighbor was investigated. We find that domain growth freezes in the case in which the second-nearest-neighbor interaction is attractive and only nearest-neighbor hops are allowed. Domain freezing is released when longer-range hops are allowed or when the second-nearest-neighbor interaction is zero. Allowing only nearest-neighbor hops, the growth exponent when there is no second-nearest-neighbor interaction is consistent with the Lifshitz-Slyozov theory. We conclude that the range of particle hops is an important parameter to consider when classifying growth kinetics
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