70 research outputs found

    Wave functions and their use in spectroscopy and phenomenology

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    We describe the calculation of Coulomb gauge wave functions for light quark systems, and their use as interpolating fields for excited state spectroscopy.Comment: 4 pages latex with lat92 macro plus 4 postscript figs, COLO-HEP-29

    Hybrid Optical Fiber Sensor And Artificial Neural Networks System For Bioethanol Quality Control And Productivity Enhancement

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    Bioethanol is produced by bio-chemical process that converts sugar or biomass feedstock into ethanol. After bio-chemical process, the solution is distilled under controlled conditions of pressure and temperature, in order to obtain an ethanol-water solution. However, the ethanol concentration analysis is generally performed off-line and, sometimes, a re-distillation process becomes necessary. In this research, an optical apparatus based on Fresnel reflection has been used in combination with artificial neural networks for determination of bioethanol concentration in hydro-alcoholic solution at any temperature. The volumetric concentration and temperature effect was investigated. This intelligent system can effectively detect and update in real-time the correction of distillation parameters to reduce losses of bioethanol and also to improve the quality in a production plant.7004Buggy, S.J., Murphy, R.P., James, S.W., Tatam, R.P., Cure monitoring of a UV cured epoxy resin using a long period grating Mach-Zehnder interferometer (2007) Proceedings of SPIE, 6619, pp. 66190VChehura, E., James, S.W., Tatam, R.P., Simultaneous, independent measurement of temperature and strain using a tilted fibre Bragg grating (2007) Proceedings of SPIE, 6619, pp. 66190IChong, J.H., Shum, P., Haryono, H., Yohana, A., Rao, M.K., Lu, C., Zhu, Y., Measurements of refractive index sensitivity using long-period grating refractometer (2004) Optics Communications, 229, pp. 65-69Su, H., Huang, X.G., Fresnel-reflection-based fiber sensor for on-line measurement of solute concentration in solutions (2007) Sensors and Actuators B: Chemical, 126 (2), pp. 579-582Meneghini, C., Caron, S., Proulx, A., Émond, F., Paradis, P., Paré, C., Fougères, A., Ethanol concentration measurement by Raman spectroscopy in liquid-core microstructured optical fiber (2007) Proceedings of SPIE, 6619, pp. 66191ULiang, W., Huang, Y., Xu, Y., Lee, R.K., Yariv, A., Highly sensitive fiber Bragg grating refractive index sensors (2005) Appl. Phys. Lett, 86, p. 151122Kheshgi, H.S., Prince, R.C., Sequestration of fermentation CO2 from ethanol production (2005) Energy, 30, pp. 1865-1871Olsson, L., Hahn-Hagerdal, B., Fermentation of lignocellulosic hydrolysates for ethanol production (1996) Enzyme and Microbial Technology, 18, pp. 312-331Natural Gas and Biofuel, ANP Resolution, (36 BRand 2005). , www.anp.gov, National Agency of PetroleumTakeishi, R.T., Gusken, E., de Souza, H.G.E., Meirelles, B.M., Suzuki, C.K., Study of the temperature effects in the alcohol-gasoline blend ratio determined by optical sensor (2007) 4th Brazilian Conference of R&D in Petroleum and Gas, , Proceedings, Campinas-SP, CD-RomBishop, C.M., (1995) Neural Networks for Pattern Recognition, , Oxford: Oxford University PressChen, S., Billings, S.A., Neural networks for nonlinear dynamic system modelling and identification (1992) International Journal of Control, 56 (2), pp. 319-346Dempsey, G.L., Alt, N.L., Olson, B.A., Alig, J.S., Control sensor linearization using a microcontroller-based neuralnetwork (1997) IEEE Intern. Conf. on Computational Cybernetics and Simulation, 4 (12-15), pp. 3078-3083. , PPLin, T.K., Chang, K.C., Lin, Y.B., Active Control with Optical Fiber Sensors and Neural Networks. II: Experimental Verification (2006) Journal of Structural Engineering, 132 (8), pp. 1304-1313Lin, T.K., Chang, K.C., Chung, L.L., Lin, Y.B., Active Control with Optical Fiber Sensors and Neural Networks. I: Theoretical Analysis (2006) Journal of Structural Engineering, 132 (8), pp. 1293-1303Rumelhart, D.E., Hinton, G., Willians, R., Learning Representation by Back-Propagation Errors (1986) Parallel Distributed Processing, 323 (9), pp. 533-536Kolodner, P., Williams, H., Moe, C., Optical measurement of the soret coefficient of ethanol/water solutions (1988) J. Chem. Phys, 88 (10), pp. 6512-6524Pan, S., Saghir, M.Z., Kawaji, M., Jiang, C.G., Yan, Y., Theoretical approach to evaluate thermodiffusion in aqueous alkanol solutions (2007) J. of Chemical Physics, 126, p. 014502González-Salgado, D., Nezbeda, I., Excess properties of aqueous mixtures of methanol: Simulation versus experiment (2006) Fluid Phase Equilibria, 240 (2), pp. 161-166. , PPPandey, J.D., Vyas, V., Jain, P., Dubey, G.P., Tripathi, N., Dey, R., Speed of sound, viscosity and R.I. of multicomponent systems: Theoretical predictions from the properties of pure components (1999) J. of Mol. Liq, 81, pp. 123-133C. K.Suzuki, E. Gusken, A. C. Mercado, E. Fujiwara, E. Ono, Fiber Optics Sensing System For Liquid Fuels, INPI Patent, Prot. 018070050521, 200

    Nanofocusing in SOI-based hybrid plasmonic metal slot waveguides

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    Abstract: Through a process of efficient dielectric to metallic waveguide mode conversion, we calculate a >400-fold field intensity enhancement in a silicon photonics compatible nanofocusing device. A metallic slot waveguide sits on top of the silicon slab waveguide with nanofocusing being achieved by tapering the slot width gradually. We evaluate the conversion between the numerous photonic modes of the planar silicon waveguide slab and the most confined plasmonic mode of a 20 x 50 nm2 slot in the metallic film. With an efficiency of ~80%, this system enables remarkably effective nanofocusing, although the small amount of inter-mode coupling shows that this structure is not quite adiabatic. In order to couple photonic and plasmonic modes efficiently, in-plane focusing is required, simulated here by curved input grating couplers. The nanofocusing device shows how to efficiently bridge the photonic micro-regime and the plasmonic nano-regime whilst maintaining compatibility with the silicon photonics platform

    Calculation of fermion loops for η\eta^\prime and nucleon scalar and electromagnetic form factors

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    The exact evaluation of the disconnected diagram contributions to the flavor-singlet pseudoscalar meson mass, the nucleon sigma term and the nucleon electromagnetic form factors, is carried out utilizing GPGPU technology with the NVIDIA CUDA platform. The disconnected loops are also computed using stochastic methods with several noise reduction techniques. Various dilution schemes as well as the truncated solver method are studied. We make a comparison of these stochastic techniques to the exact results and show that the number of noise vectors depends on the operator insertion in the fermionic loop.Comment: Version accepted for publication in Comp. Phys. Commun. References added. 13 pages, 12 figure

    Hybrid Meson Spectrum from the FLIC action

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    The spectral properties of hybrid meson interpolating fields are investigated. The quantum numbers of the meson are carried by smeared-source fermion operators and highly-improved chromo-electric and -magnetic field operators composed with APE-smeared links. The effective masses of standard and hybrid operators indicate that the ground state meson is effectively isolated using both standard and hybrid interpolating fields. Focus is placed on interpolating fields in which the large spinor components of the quark and antiquark fields are merged. In particular, the effective mass of the exotic 1+1^{-+} meson is reported. Further, we report some values for excited mesonic states using a variational process.Comment: Talk given by A.G Williams at Workshop on Lattice Hadron Physics, Cairns, Queensland, Australia, July 200

    Hybrid and Exotic Mesons from FLIC Fermions

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    The spectral properties of hybrid meson interpolating fields are investigated. The quantum numbers of the meson are carried by smeared-source fermion operators and highly-improved chromo-electric and -magnetic field operators composed with APE-smeared links. The effective masses of standard and hybrid operators indicate that the ground state meson is effectively isolated using both standard and hybrid interpolating fields. Focus is placed on interpolating fields in which the large spinor components of the quark and antiquark fields are merged. In particular, the effective mass of the exotic 1+1^{-+} meson is reported. Further, we port some values for excited mesonic states using a variational process.Comment: 3 Pages, 3 figures, Lattice2003(Spectrum

    Hadron Mass Extraction from Lattice QCD

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    The extraction of quantities from lattice QCD calculations at realistic quark masses is of considerable importance. Whilst physical quark masses are some way off, the recent advances in the calculation of hadron masses within full QCD now invite improved extrapolation methods. We show that, provided the correct chiral behaviour of QCD is respected in the extrapolation to realistic quark masses, one can indeed obtain a fairly reliable determination of masses, the sigma commutator and the J parameter. We summarise these findings by presenting the nonanalytic behaviour of nucleon and rho masses in the standard Edinburgh plot.Comment: Talk presented by S. V. Wright at the Workshop on Lattice Hadron Physics (LHP2001), Cairns, Australia, 9-18 July 2001, 8 pages, requires espcrc2.sty (included

    Lattice QCD Calculations of the Sigma Commutator

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    As a direct source of information on chiral symmetry breaking within QCD, the sigma commutator is of considerable importance. With recent advances in the calculation of hadron masses within full QCD it is of interest to see whether the sigma commutator can be calculated directly from the dependence of the nucleon mass on the input quark mass. We show that provided the correct chiral behaviour of QCD is respected in the extrapolation to realistic quark masses one can indeed obtain a fairly reliable determination of the sigma commutator using present lattice data. Within two-flavour, dynamical-fermion QCD the value obtained lies in the range 45 to 55 MeV.Comment: 7 pages, 2 figure

    Electromagnetic Form Factors with FLIC fermions

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    The Fat-Link Irrelevant Clover (FLIC) fermion action provides a new form of nonperturbative O(a) improvement and allows efficient access to the light quark-mass regime. FLIC fermions enable the construction of the nonperturbatively O(a)-improved conserved vector current without the difficulties associated with the fine tuning of the improvement coefficients. The simulations are performed with an O(a^2) mean-field improved plaquette-plus-rectangle gluon action on a 20^3 x 40 lattice with a lattice spacing of 0.128 fm, enabling the first simulation of baryon form factors at light quark masses on a large volume lattice. Magnetic moments, electric charge radii and magnetic radii are extracted from these form factors, and show interesting chiral nonanalytic behavior in the light quark mass regime.Comment: Presented by J.Zanotti at the Workshop on Lattice Hadron Physics, Cairns, Australia, 2003. 7pp, 8 figure

    NRQCD Results on Form Factors

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    We report results on fBf_B and semi-leptonic BB decay form factors using NRQCD. We investigate 1/M1/M scaling behavior of decay amplitudes. For fBf_B Effect of higher order relativistic correction terms are also studied.Comment: 9 pgs. 10 figures. Latex2e. espcrc2.sty included. Talk presented at the Internatioal Workshop "LATTICE QCD ON PARALLEL COMPUTERS", March 1997, Tsukub
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