FORMULA ON ENERGY LOSSES AT THREE-WAY CIRCULAR DROP MANHOLE UNDER SURCHARGE FLOW
1Member of JSCE, Professor, Dept. of Civil and Environmental Eng., National Institute of Technology, Matsue College (14-4 Nishi-ikuma, Matsue, Shimane 690-8518, Japan) E-mail: arao@matsue-ct.jp 2Member of JSCE, Electric Power Development Co., Ltd. (15-1 Ginza 6-chome, Chuo-ku, Tokyo 104-8165, Japan) E-mail: Shunsuke_Hiratsuka@jpower.co.jp 3Honorary Member of JSCE, Professor, Kyushu University (744 Motooka, Nish-ku, Fukuoka 819-0395, Japan) E-mail: kusuda@kyudai.jp
Performance of Model Storm Sewer Junctions
The design of an effective storm water junction structure requires calculation of the energy losses, and associated backwater effects, in the vicinity of the junction under anticipated maximum flows in the incoming sewers. In the case of hydraulically inefficient junctions, energy losses due to stream mixing and from drag can lead to surcharged conditions in the conduits. Under these conditions Sangster suggests appropriate energy loss coefficients based on extensive tests on small-scale junction structures in which the inflow and outflow pipes were surcharged. However, efficient storm sewer systems normally operate under free surface conditions. Consequently the experimental program, described in this note, had the following main objectives: 1. To provide data on the relative efficiency of different-shaped junction structures operating under free surface conditions; 2. to investigate junctions having large inlet pipe diameters and small incoming pipe slopes; and 3. determination of suitable modifications to junction geometry in light of recent attempts to improve the performance of some inefficient junctions in an existing sewer system.
Refinement of crystal structure parameters using convergent‐beam electron diffraction: the low‐temperature phase of SrTiO3
The method to refine crystal structure parameters (atom positions and Debye–Waller factors) using convergent-beam electron diffraction (CBED), which is applicable to crystal structure analysis of a small specimen area down to a few nm in diameter, is studied. The line profiles of higher-order Laue-zone reflections are recorded using imaging plates. Theoretical intensities are calculated based on the dynamical theory of electron diffraction with the aid of the generalized Bethe approximation to shorten calculation time. The structural parameters are determined by fitting the experimental profiles with the theoretical ones using a nonlinear least-squares method. The present method has been applied to the low-temperature phase of SrTiO3. The structural parameter or the rotation angle of the oxygen octahedron has been determined to be \varphi = 1.12 (4)°, which shows good agreement with that obtained from electron spin resonance experiments.