68 research outputs found

    Statiscal Analysis on Stream Pollution : I. Factor Analysis on Stream Pollution of the Yodo River

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    In order to obtain the composite pollution index which may be available as the evaluation of the degree of gross stream pollution, factor analysis was carried out using monthly water examination data from 1923 to 1958 at Kunijima intake crib. Ten items i.e. turbibity, pottasium permanganate consumed, color, general bacteria count, residue by evaporation, total nitrogen, chlor ion concentration, hardness, stream flow rate and stream water temperature were adopted as variables in factor analysis. From the results of factor analysis, three definite factors i.e. pollution factor, rainfall factor and air temerature factor were identified, and correlations between these three factors and ten variables were elucidated. Computing the β weights for pollution factor, the composite pollution index was obtained

    Statistical Analysis on Stream Pollution : II. Time Series Analysis on Stream Pollution of the Yodo River

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    The time series analysis was carried out, using the composite pollution index calculated from the monthly water examination data from 1946 to 1960 at the Kunijima intake crib, in order to evaluate the stream pollution of the Yodo River in the future. From the results obtained, it was estimated that the composite pollution index will be increased by 1.2~2.6 with a 25% level of significance at the end of 1967

    An Experimental Study on the Diffusion Characteristics of Turbulent Flow in a Low Speed Wind Tunnel

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    This paper describes the results of a study on diffusion characteristics of turbulent flow in a wind tunnel, in which the turbulent flow was obtained by a grid. The lateral turbulent velocity deviation ranged from 1.01 to 1.14 times the longitudinal turbulent velocity deviation for mean wind velocities from 2 to 8 m/sec and mesh sizes of grid from 4.5 to 13.5 cm, and the isotropic condition was almost satisfied. The decay of turbulence was expressed with the equation /U=m(x/M)⁻α, where : longitudinal turbulent velocity variance, U : mean wind velocity, x : distance from the grid, M : mesh size of the grid, and α, m are constants. From 11 tracer gas experiments, we obtained the Lagrangian correlation coefficient and found the Lagrangian and Eulerian correlation coefficients had similar shapes within the range of time-lag from 0 to 400 milliseconds. The ratios of the Lagrangian to Eulerian time scale, β, were between 4 and 11

    Cooperation among c-subunits of FoF1-ATP synthase in rotation-coupled proton translocation

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    In F₀F₁-ATP synthase, proton translocation through F₀ drives rotation of the c-subunit oligomeric ring relative to the a-subunit. Recent studies suggest that in each step of the rotation, key glutamic acid residues in different c-subunits contribute to proton release to and proton uptake from the a-subunit. However, no studies have demonstrated cooperativity among c-subunits toward F₀F₁-ATP synthase activity. Here, we addressed this using Bacillus PS3 ATP synthase harboring a c-ring with various combinations of wild-type and cE56D, enabled by genetically fused single-chain c-ring. ATP synthesis and proton pump activities were decreased by a single cE56D mutation and further decreased by double cE56D mutations. Moreover, activity further decreased as the two mutation sites were separated, indicating cooperation among c-subunits. Similar results were obtained for proton transfer-coupled molecular simulations. The simulations revealed that prolonged proton uptake in mutated c-subunits is shared between two c-subunits, explaining the cooperation observed in biochemical assays

    Candidate Brown-dwarf Microlensing Events with Very Short Timescales and Small Angular Einstein Radii

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    Short-timescale microlensing events are likely to be produced by substellar brown dwarfs (BDs), but it is difficult to securely identify BD lenses based on only event timescales t_E because short-timescale events can also be produced by stellar lenses with high relative lens-source proper motions. In this paper, we report three strong candidate BD-lens events found from the search for lensing events not only with short timescales (t_E ≲ 6 days) but also with very small angular Einstein radii (θ_E ≲ 0.05 mas) among the events that have been found in the 2016–2019 observing seasons. These events include MOA-2017-BLG-147, MOA-2017-BLG-241, and MOA-2019-BLG-256, in which the first two events are produced by single lenses and the last event is produced by a binary lens. From the Monte Carlo simulations of Galactic events conducted with the combined t_E and θ_E constraint, it is estimated that the lens masses of the individual events are 0.051^(+0.100)_(−0.027) M⊙, 0.044^(+0.090)_(−0.023) M⊙, and 0.046^(+0.067)_(−0.023) M⊙/0.038^(+0.056)_(−0.019) M⊙ and the probability of the lens mass smaller than the lower limit of stars is ~80% for all events. We point out that routine lens mass measurements of short-timescale lensing events require survey-mode space-based observations

    A Gas Giant Planet in the OGLE-2006-BLG-284L Stellar Binary System

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    We present the analysis of microlensing event OGLE-2006-BLG-284, which has a lens system that consists of two stars and a gas giant planet with a mass ratio of qp=(1.26±0.19)×103q_p = (1.26\pm 0.19) \times 10^{-3} to the primary. The mass ratio of the two stars is qs=0.289±0.011q_s = 0.289\pm 0.011, and their projected separation is ss=2.1±0.7s_s = 2.1\pm 0.7\,AU, while the projected separation of the planet from the primary is sp=2.2±0.8s_p = 2.2\pm 0.8\,AU. For this lens system to have stable orbits, the three-dimensional separation of either the primary and secondary stars or the planet and primary star must be much larger than that these projected separations. Since we do not know which is the case, the system could include either a circumbinary or a circumstellar planet. Because there is no measurement of the microlensing parallax effect or lens system brightness, we can only make a rough Bayesian estimate of the lens system masses and brightness. We find host star and planet masses of ML1=0.350.20+0.30MM_{L1} = 0.35^{+0.30}_{-0.20}\,M_\odot, ML2=0.100.06+0.09MM_{L2} = 0.10^{+0.09}_{-0.06}\,M_\odot, and mp=14482+126Mm_p = 144^{+126}_{-82}\,M_\oplus, and the KK-band magnitude of the combined brightness of the host stars is KL=19.71.0+0.7K_L = 19.7^{+0.7}_{-1.0}. The separation between the lens and source system will be 90\sim 90\,mas in mid-2020, so it should be possible to detect the host system with follow-up adaptive optics or Hubble Space Telescope observations
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