464 research outputs found

    A review of the Japanese longline fishery for tunas and billfishes in the Eastern Pacific Ocean, 1971-1980

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    ENGLISH: This report reviews the Japanese longline fishery for tunas and billfishes in the eastern Pacific Ocean during 1971-1980, extending the studies made by other investigators, which covered the 1956-1970 period. The spatial and temporal distributions of fishing effort, catch, apparent abundance, sexual maturity, and size composition are examined for each species. The deep longlining method is described and the hook rates for this gear and for conventional longline gear are compared. Some observations on the interaction of surface and longline gear are reported. SPANISH: Se examina en este informe la pesca palangrera japonesa de atunes y peces espada en el Océano Pacífico oriental durante 1971-1980, ampliando los estudios hechos por otros investigadores que incluían el período de 1956-1970. Para cada especie se examinan las distribuciones temporales y espaciales del esfuerzo de pesca, captura, abundancia aparente, madurez sexual y composición de talla. Se describe el método de los palangres profundos y se comparan los índices de captura por anzuelo de este arte y del arte convencional palangrero. Se presentan algunas observaciones sobre la interacción de las artes espipelágicas y las palangreras. (PDF contains 163 pages.

    Heat Transfer Characteristics of Regenerator Matrix (Case of Packed Wire Gauzes)

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    The average heat transfer coefficient in the matrix of laminated wire screens (10 to 250 mesh) for a Stirling engine heat exchanger was studied experimentally. The data are correlated by N sub ud = 0.42 R sub ed 0.56 (3 or = R sub ed or = 400), and R sub ed are the Nusselt and Reynolds nubmers based on the wire diameter. The pressure drop decreased and the heat transfer increased as the wire diameter was decreased

    Two-particle interference of electron pairs on a molecular level

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    We investigate the photo-doubleionization of H2H_2 molecules with 400 eV photons. We find that the emitted electrons do not show any sign of two-center interference fringes in their angular emission distributions if considered separately. In contrast, the quasi-particle consisting of both electrons (i.e. the "dielectron") does. The work highlights the fact that non-local effects are embedded everywhere in nature where many-particle processes are involved

    Photoproduction of Lambda(1405) and Sigma^{0}(1385) on the proton at E_\gamma = 1.5-2.4 GeV

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    Differential cross sections for γpK+Λ(1405)\gamma p \to K^+\Lambda(1405) and γpK+Σ0(1385)\gamma p \to K^+\Sigma^0(1385) reactions have been measured in the photon energy range from 1.5 to 2.4 GeV and the angular range of 0.8<cos(Θ)<1.00.8<\cos(\Theta)<1.0 for the K+K^+ scattering angle in the center-of-mass system. This data is the first measurement of the Λ(1405)\Lambda(1405) photoproduction cross section. The lineshapes of \LamS measured in Σ+π\Sigma^+\pi^- and Σπ+\Sigma^-\pi^+ decay modes were different with each other, indicating a strong interference of the isospin 0 and 1 terms of the Σπ\Sigma\pi scattering amplitudes. The ratios of \LamS production to \SigS production were measured in two photon energy ranges: near the production threshold (1.5<Eγ<2.01.5<E_\gamma<2.0 GeV) and far from it (2.0<Eγ<2.42.0 <E_\gamma<2.4 GeV). The observed ratio decreased in the higher photon energy region, which may suggest different production mechanisms and internal structures for these hyperon resonances