5,512 research outputs found

    Investigation of environmental change pattern in Japan: Investigation of variations in the prominent oceanic current, Kuroshio

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    The author has identified the following significant results. In the print of MSS band 4 of Shiono Misaki and Ise taken by LANDSAT on 11 September 1975, different water masses can be recognized distinctly. At 35 miles off Shiono Misaki, a vortex pattern is found which has an ellipsoidal shape with a diameter of 30 miles and appears to rotate counterclockwise. In Ise, water masses were found spreading widely along the coast from the mouth of Ise Bay. The temperature of sea surface obtained from sea truth shows almost a uniform pattern. The distribution of surface salinity and transparency shows a distinct pattern

    Modeling of vegetated rivers for inbank and overbank flows

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    Model parameters such as friction factor and eddy viscosity in the Shiono & Knight method (SKM) are considered through experimental data obtained from a vegetated open channel. The experiment was conducted in a rectangular open channel with cylindrical rods as vegetation. Velocity, Reynolds stresses and boundary shear stress were measured with Acoustic Doppler Velocimetry (ADV) and a Preston tube re-spectively. Both friction factor and eddy viscosity were calculated using the measured data and found to be not constant in the shear layer generated by rods. The analytical solutions of SKM to predict velocity and boundary shear stress currently in use were based on the constant assumption of these parameters. In this pa-per a new analytical solution was derived by taking into a variation of these parameters account and was also verified with the experimental data. This solution was also applied to flow in compound channel with vegeta-tion. The new solution gives a good prediction of the lateral distribution of depth-averaged velocity and boundary shear stress in vegetated channels, and it predicts the boundary shear stress better than that of the original solution without considering the secondary flow term in particular

    A numerical study of the complex flow structure in a compound meandering channel

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    [EN] In this study, we report large eddy simulations of turbulent flow in a periodic compound meandering channel for three different depth conditions: one in-bank and two overbank conditions. The flow configuration corresponds to the experiments of Shiono and Muto (1998). The predicted mean streamwise velocities, mean secondary motions, velocity fluctuations, turbulent kinetic energy as well as mean flood flow angle to meandering channel are in good agreement with the experimental measurements. We have analyzed the flow structure as a function of the inundation level, with particular emphasis on the development of the secondary motions due to the interaction between the main channel and the floodplain flow. Bed shear stresses have been also estimated in the simulations. Floodplain flow has a significant impact on the flow structure leading to significantly different bed shear stress patterns within the main meandering channel. The implications of these results for natural compound meandering channels are also discussed.Moncho Esteve, IJ.; García-Villalba, M.; MUTO Y.; SHIONO K.; Palau-Salvador, G. (2018). A numerical study of the complex flow structure in a compound meandering channel. Advances in Water Resources. 116:95-116. https://doi.org/10.1016/j.advwatres.2018.03.013S9511611

    Investigation of environmental change pattern in Japan. Investigation of variations in the prominent oceanic current, Kuroshio

    Get PDF
    The author has identified the following significant results. It was confirmed that band 4 and 5 had some information as to the sea surface, such as spreading of coastal waters or eddy-like motion of surface water. It was concluded that the front line along the coast from Kumano-nada to Shiono-misaki in the monochromatic prints and in the pseudocolor images was a boundary between coastal waters and offshore water. Most of Ise Bay was covered by polluted water, having salinity values less than 30%, high water color scale of 6 to 8, and transparency less than 5 m

    Morphological detection of X- and Y-chromosomes in smears and paraffin-embedded tissues using a non-isotopic in situ hybridization technique (NISH)

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    Pharyngeal smears and paraffin-embedded tissue specimens (skeletal muscle, kidney) obtained from 10 male and 10 female individuals were evaluated using non-isotopic in situ hybridization (NISH) with commercial X- and Y-specific biotinylated probes which recognize the pericentromeric regions DXZ1 and DYZ1/DYZ3 of the X- and Y-chromosome, respectively. The results provide evidence that the morphological sex determination of a single cell can be performed by critical application of this staining method leading to one nuclear signal in ldquomalerdquo cells using the Y-specific probe whereas ldquofemalerdquo cells are negative. In situ hybridization of ldquofemalerdquo tissues with an X-specific probe results regularly in 2 signals whereas ldquomalerdquo cells show only one spot in the nucleus

    ISFET based enzyme sensors

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    This paper reviews the results that have been reported on ISFET based enzyme sensors. The most important improvement that results from the application of ISFETs instead of glass membrane electrodes is in the method of fabrication. Problems with regard to the pH dependence of the response and the dynamic range as well as the influence of the sample buffer capacity have not been solved. As a possible solution we introduce a coulometric system that compensates for the analyte buffer capacity. If the pH in the immobilized enzyme layer is thus controlled, the resulting pH-static enzyme sensor has an output that is independent of the sample pH and buffer capacity and has an expanded linear range

    UV-isomerisation in nematic elastomers as a route to photo-mechanical transducer

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    The macroscopic shape of liquid crystalline elastomers strongly depends on the order parameter of the mesogenic groups. This order can be manipulated if photoisomerisable groups, e.g. containing N=N bonds, are introduced into the material. We have explored the large photo-mechanical response of such an azobenzene-containing nematic elastomer at different temperatures, using force and optical birefringence measurements, and focusing on fundamental aspects of population dynamics and the related speed and repeatability of the response. The characteristic time of ``on'' and ``off'' regimes strongly depends on temperature, but is generally found to be very long. We were able to verify that the macroscopic relaxation of the elastomer is determined by the nematic order dynamics and not, for instance, by the polymer network relaxation.Comment: Latex (EPJE class) 12 figure

    Experimental Characterization of straight compound-channel turbulent field

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    Straight compound-channel flows have been studied by many authors, mainly concerned with mean flow variables. Detailed information on the complex turbulent field of these flows is still scarce. In the present paper, high data rate measurements were obtained for the streamwise and vertical velocity components, using a 2D Laser Doppler Velocimeter in a experimental compound flume. The filtered velocities time series allowed the computation of relevant turbulence statistics: autocorrelation functions, dissipation spectra, turbulence scales and dissipation rate. The results are analyzed by comparison with universal laws drawn for isotropic turbulent 2D fully developed open-channel flow. The presence of strong secondary currents does not affect the universal law in the floodplain, as long as the constants are changed. In the main channel the 3D behavior of the flow is more pronounced and the universal laws fail to reproduce accurately the experimental result
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