岡山大学工学部 Acta Medica Okayama 0475-0071 14 1 1979 Ozonation of Organic Substances from View Points of Wastewater Treatment 139 150 EN 10.18926/15747 In this paper, ozonation of organic substances which are found in wastewater is discussed regarding following respects; (1)removal ratios of COD(Cr) and TOC, (2)removal properties, and (3)oxidation products. The main results are summarized as follows. (l)Ozonation quickly removes proteins and amino acids, but mildly polysaccharides and n-saturated carboxylic acids. (2)The initial removal of COD(Cr) or TOC is quite rapid, but, as the reaction continues, it slows down so drasti-cally that one may suspect that it has completed. (3)Starch and albumine are decomposed to the smaller molecular compounds. (4)The COD(Cr) /TOC ratio of each substance which is chosen in this study decreases. This means that ozonation results in the formation of oxygenated fragments of the original molecule-occurs by bond fission or partial oxidation. (5)Proteins are indispensable components in frothing because they are surface active. They are removed by not only oxidation but also foaming, however, the removal by foaming is not so large. No potential conflict of interest relevant to this article was reported.

岡山大学工学部 Acta Medica Okayama 0475-0071 14 1 1979 Discharge Coeffi cient of a Sluice Gate Placed at Sudden Expansion of Open Channel 127 138 EN 10.18926/15746 In this paper the discharge coefficient of a sluice gate placed at the sudden expansion of an open channel is investigated theoretically and experimentally. Lateral and vertical expansions are treated in the study. The coefficients obtained for channels with sudden expansion are compared with those for the straight channel. For free efflux, experimental results show that the coeffcients for expanded channels are always larger than those for a straiaht one,and that the coefficient for a channel to be fully expanded to both lateral and vertical directions takes about 1.2 times larger value than that for a straight one. For submerged efflux, the coefficient is obtained theoretically by using the efflux model shown in this study. The theoretical results explain the experimental ones fairly well. The coefficient for lateral expansion is always smaller than that for a straight channel. The minimum downstream water depth required to submerged efflux for the expanded channels becomes smaller than that for a straight channel. No potential conflict of interest relevant to this article was reported.

岡山大学工学部 Acta Medica Okayama 0475-0071 14 1 1979 Transient Flow in Groundwater to Wells in Island Model Aquifer 95 126 EN 10.18926/15744 In order to apply the numerical method to practical groundwater flow problem in the field, the hydraulic properties must be estimated. In this paper, new methods of analyzing drawdown tests were developed and illustrated with some examples to determine hydraulic properties of aquifer. Drawdown tests sometimes have to be performed near the boundary of the aquifer or in the much groundwater supplied aquifer. In such instances, the assumption that the aquifer is of infinite areal extent is no longer valid. Therefore the analytical solutions of unsteady flow due to drawdown test are derived in the conception of "Island Model" that the shape of groundwater level is fixed by the circular water supply which is equilibrium with the pumping rate. By using these solutions, new methods of analyzing drawdown tests which are performed in a confined aquifer and an unconfined aquifer were given respectively and the effect of influence region was evaluated. The example analysis to determine permeability and storage coefficient were shown. As the results,the propriety of the solutions is verified comparing the analytical results with the drawdown test data taken from a real aquifer project. No potential conflict of interest relevant to this article was reported.

岡山大学工学部 Acta Medica Okayama 0475-0071 14 1 1979 Application of Fininite Element Analysis to Groundwater Flow in Field Problems 61 94 EN 10.18926/15742 The purposes of this paper are primarily to research on behavior of groundwater flow in saturated and unsaturated zone and to develop the most effective methods for solving groundwater flow problems related to civil engineering practice. The mathematical model provides a finite element solution to two- or threedimensional problems involving transient flow in the saturated and unsaturated domains of nonhomogeneous, anisotropic porous media. Before progressing into the various levels of applications the input data and boundary conditions are discussed and evaluated. To demonstrate the flexibility of the finite element approach and its capability in treating complex situations which are often encountered in the field, the groundwater flow through sand bank at flood water levels and the flow through aquifer due to an excavation were analyzed. As the results there were good qualitative agreements between the numerical results and the informations received. No potential conflict of interest relevant to this article was reported.

岡山大学工学部 Acta Medica Okayama 0475-0071 14 1 1979 Absorption Spectrum Measurement for Atmospheric Level Nitric Monoxide in γ-0 Band and Its Density Deduction 55 60 EN Ryuji Koga Keiji Hirao Megumi Kosaka Hiroya Sano 10.18926/15740 An absorption spectrum of γ-0 band of nitric monoxide of very dilute density was taken. An experimental electronic device showed a distinguishing power of 0.01 ppm through 10 m optical pathlength. By the aid of a data processing based on a principle developed by the authors, this sensitivity does not suffer from coexisting sulfur dioxide, which shares the absorption band with the nitric monoxide. No potential conflict of interest relevant to this article was reported.

岡山大学工学部 Acta Medica Okayama 0475-0071 14 1 1979 Behaviors of a Soliton in Nonlinear L-C Lines with Abrupt Parameter Change 39 53 EN Shigeji Nogi Kiyoshi Fukui 10.18926/15739 Some behaviors of a lattice soliton in nonlinear L-C ladder lines with abrupt parameter change are investigated. The results of computer and circuit experiments show that in the case of a soliton incident upon the line of larger characteristic impedance and of higher phase velocity in linearized-line-limit, the transmitted wave evolves into larger number of solitons. The experimental results can be well explained by use of both linearization approximation for the line near the junction and the theory by Gardner, Greene, Kruskal and Miura. No potential conflict of interest relevant to this article was reported.

岡山大学工学部 Acta Medica Okayama 0475-0071 14 1 1979 Dynamic Switching of Wall-Reattachment Fluidic Device 29 37 EN 10.18926/15738 Effect of the geometrical configuration of wall-reattachment fluidic device on the switching dynamics, the switching time, and its dispersion, was investigated experimentally by using a large scale model. The results obtained can be summarized as follows: 1) The switching time, its dispersion, and switching probability depend upon the connection of the input to the control port. 2) Effect of the vent and splitter on the jet in dynamic switching is explained commonly by using the margin of a given control flow rate to the switching control flow rate. 3) The switching time ,decreases as input increases, whereas its dispersion remains constant except for small input. No potential conflict of interest relevant to this article was reported.

岡山大学工学部 Acta Medica Okayama 0475-0071 14 1 1979 Iron Losses of Silicon Steel due to Rotating Fluxes (Inclined Rotating Flux and Distorted One) 15 28 EN 10.18926/15736 Characteristics of iron losses in silicon steel due to inclined rotating fluxes and distorted ones are described. Iron losses due to rotating fluxes have been measured at various conditions for grain-oriented and non-oriented silicon steels by using an improved thermistor-bridge method. Loss measurements indicate that the iron loss due to the inclined rotating flux is greater than that due to the non-inclined one. However, the iron loss due to the distorted rotating flux is not always greater than that due to the non-distorted one. No potential conflict of interest relevant to this article was reported.

岡山大学工学部 Acta Medica Okayama 0475-0071 14 1 1979 Oriented Crystallization of Polyethylene at High Pressure from Flowed Melt 9 14 EN 10.18926/15735 In the course of the study of polymer crystallization at high pressure, oriented crystallization of extended chain crystals of polyethylene were examined. Molten polyethylene were extruded into a die at a few hundred atm, and follwed by crystallization by high pressure application above 3000 atm. Resulting sample shows chain orientation to extruded direction. Thick lamella nearly a few thousand angstrom, which are typical feature of high pressure crystallization, were observed to be stacked parallel each other. In spite of favorable condition for crystals to grow to chain direction, remarkable growth to normal direction to them were also observed. No potential conflict of interest relevant to this article was reported.

岡山大学工学部 Acta Medica Okayama 0475-0071 14 1 1979 The Molecular Mechanism of Chain Tilt in Poly (ethylene terephthalate) Fibers 1 7 EN 10.18926/15734 The molecular mechanism of chain tilt in poly(ethylene terephthalate) (PET) fibers was proposed. The mechanism was considered basing on the ordering process from the cold drawn state of glassy PET. It was confirmed that the direction of maximum contraction on ordering agrees with the azimuth of chain tilt which varies with annealing temperature. In the stacking structure of irregular folded chain blocks of cold drawn PET, the expansion to the chain direction and the contraction to the lateral direction yield the compressive stress and tensile stress r respectively. The stress revealed as the result of the ordering from the glassy structure to crystalline structure can be relaxed by the rotation of the resulting crystallites. Therefore, we can suggest that the chain tilt is caused by the relaxation process of the stress. No potential conflict of interest relevant to this article was reported.