| JaLCDOI | 10.18926/15795 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_16_1_65.pdf |
| Author | Kohno Iichiro| Nishigaki Makoto| |
| Abstract | The purposes of this research is an investigation of the intrusion of sea water into coastal aquifers. For this subject, this paper deals with proposing rational methods of getting diffusion coefficient and dispersion parameter for flow in porous media in a laboratory. These parameters of soil are indispensable in order to apply an analytical approach or a numerical approach to actual salt water intrusion problems. Experimental apparatuses were constructed and test procedures were also developed to measure concentration behaviors in a saturated porous media by using electro conductivity probe. As the results, the diffusion coefficients for the Toyoura standard sand and the Asahi river sand determined by two methods, that is, "Boltzman's transformation method" and "Instantaneous profile analysis method". The longitudinal coefficient of dispersion for one-dimensional flow was also determined by the least squares curve fitting method with a function of a certain range of seepage velocity. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1982-03-01 |
| Volume | volume16 |
| Issue | issue1 |
| Start Page | 65 |
| End Page | 89 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307205 |
| JaLCDOI | 10.18926/15691 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_5_47.pdf |
| Author | Takahashi Katsuaki| Miura Yoshinari| |
| Abstract | Diffusion phenomena of silver ion in the molten sodium diborate of low silver ion content were investigated at the temperature range from 880℃ to 625℃ by means of chronopotentiometry. From the results, it was shown that the silver ion was reduced reversibly to metallic state at the silver electrode used and silver ion was transported only by diffusion in case that transition time in a potential-time relation was within several seconds. Diffusion coefficients measured at various temperatures satisfied Arrhenius equation. The activation energy of diffusion and diffusion coefficient were respectively 32Kcal/mol and 6.5×10(-7) cm(2)/sec at the liquidous temperature. By comparing these values with those obtained in some molten salts, the difference of structure between the molten glass and molten salts was discussed. Moreover, the consideration for the size of borate anion existing in the molten glass was also tried from the viewpoint of rate process and from Stokes-Einstein's equation. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1970-09-01 |
| Volume | volume5 |
| Issue | issue1 |
| Start Page | 47 |
| End Page | 53 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307810 |
| JaLCDOI | 10.18926/15542 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_1_37.pdf |
| Author | Takahashi Katsuaki| Tanioka Mamoru| Yoshio Tetsuo| |
| Abstract | Studies were carried out in order to know in some detail the transport phenomena through the interface in the viscous liquid moving in laminar flow. Experiments were carried out using ca. 88% glycerin solution, one added with an acid, and the other with alkali together with a small amount of phenolphthalein. Acidic glycerin solution was supplied to a long transparent cuvette of rectangular cross section through which the liquid was made to move slowly enough to establish the laminar flow, thin cords of coloured basic solution were introduced in the direction normal to the axis of flow at regular time intervals. The so obtained patterns of bending cords shortening in regular succession were photographed also at regular time intervals. The authors attribute the origin of the changing patterns of the cords to the velocity gradient existing in the acidic solution which accelerates the diffusion by increasing the concentration gradient near the cords as well as the increase of the interfacial area, and also the decrease of the thickness of the cords. Based on these idea a mathematical analysis was carried out and was obtained an equation which gives the change of the concentration distribution of two dimensional cords. Fair agreement was obtained between the results of mathematical analysis and those of experiments. Furthermore, the influence of the thickness of the cords, and that of the velocity gradient as well as of the diffusion coefficient on the concentration at the center of the cords were discussed. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1966-03-31 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 37 |
| End Page | 43 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307624 |
| JaLCDOI | 10.18926/15746 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_14_1_127.pdf |
| Author | Nago Hiroshi| Furukawa Syuzo| |
| Abstract | 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. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-12-01 |
| Volume | volume14 |
| Issue | issue1 |
| Start Page | 127 |
| End Page | 138 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307258 |
| JaLCDOI | 10.18926/15782 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_15_2_133.pdf |
| Author | Mori Chuji| Taniguchi Takeo| Kimoto Teruyuki| |
| Abstract | From the theoretical approach to the fill-in minimization problem we present one of the optimal vertex elimination process for a regular finite element mesh M (nxn), and through a number of numerical experiments it is verified that the new process model can always lead to better numerical results comparing to other methods presently in use. Since the process here presented cann't give the actual dissections of M but can clarify how the optimal elimination is, the process includes George's Nested Dissection Method and the method by Duff, Erisman and Reid. By this investigation we can conclude that l) the concept of "Dissection" is neccessary for minimizing the number of fill-ins, 2) the location of the dissection lines can be systematically decided even if n of M is odd or even number, and though the interior area of M is dissected as George's Method, the surrounding area of M is rather irregularily dissected, and 3) the model of the vertex elimination process given in this paper is applied to other kind of regular finite element mesh or finite difference mesh, too. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1981-03-30 |
| Volume | volume15 |
| Issue | issue2 |
| Start Page | 133 |
| End Page | 146 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307564 |
| JaLCDOI | 10.18926/15836 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_21_1_81.pdf |
| Author | Nago Hiroshi| Maeno Shiro| |
| Abstract | Under the attack of storm waves, there are many destructions of coastal structures due to scouring, sinking and sliding. These types of destructions are considered to be in close relation to the dynamic behavior of sand bed around the structures. In this study the characteristics of pore water pressure and stresses in the sand bed around a breakwater under the attack of superposed waves are treated theoretically. The results show that during the crest or the trough being in front of the structure the strength of sand bed around the structure decreases notably and the unstable zone will occur. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1986-11-15 |
| Volume | volume21 |
| Issue | issue1 |
| Start Page | 81 |
| End Page | 91 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307224 |
| JaLCDOI | 10.18926/15822 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_20_2_35.pdf |
| Author | Nago Hiroshi| Maeno Shiro| |
| Abstract | Under the attack of storm waves, there are many destructions of coastal structures in the forms of sinking and sliding. These types of destructions will be in close relation to the dynamic behavior of sand bed around the structures. From this point of view, in this paper, we investigate the characteristics of the pore water pressure and effective stresses in the highly saturated sand bed under oscillating water pressure theoretically. The results indicate that the oscillating water pressure induce the notable drop of strength of sand bed around the structure under certain condition. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1986-02-28 |
| Volume | volume20 |
| Issue | issue2 |
| Start Page | 35 |
| End Page | 45 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307664 |
| JaLCDOI | 10.18926/15660 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_8_2_52.pdf |
| Author | Wada Tsutomu| Shimizu Akira| Dohta Shujiro| |
| Abstract | The dynamic behaviour of attaching jet with single side wall to step control flow and the switching proces of the bistable amplifiers were investigated experimentally and theoretically. In the experiments, a large scale model was used with water. The flow patterns were visualized by the tracer of polystrene granules and were recorded by a cinecamera. In the analysis, the quasi-steady proces was assumed. The results obtained can be summarized as follows: 1) The proposed analytical dynamic model of attaching jet explains well the dynamic behaviour of attaching jet with single side wall. 2) The process" of the opposite wall switching may be divided into three phases. 3) The analytical model of the opposite wall switching, including the formulation of the switching criterion, was proposed. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1973-12-26 |
| Volume | volume8 |
| Issue | issue2 |
| Start Page | 52 |
| End Page | 65 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307728 |
| JaLCDOI | 10.18926/15671 |
|---|---|
| FullText URL | 009_02_107_118.pdf |
| Author | Okamoto Takuji| Misaki Takayoshi| |
| Abstract | The dynamic design of a tunnel-diode-transistor combined circuit and the applied pulse circuits are discussed. The combined circuit, in which a tunnel diode is connected in parallel with the collector junction of a transistor, is used. The dynamic design procedure is considerably simplified by describing the transient behavior of a tunnel diode with a set of approximate expressions and by the help of a selfanalog simulator. This circuit is capable of carrying out both memory and majority logic operations, and serves as a basic unit for several different pulse circuits, such as a mcnostable circuit, a frequency divider, a ring counter, etc. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1974-12-25 |
| Volume | volume9 |
| Issue | issue2 |
| Start Page | 107 |
| End Page | 118 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307235 |
| JaLCDOI | 10.18926/15738 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_14_1_29.pdf |
| Author | Wada Tsutomu| Shimizu Akira| Dohta Shujiro| |
| Abstract | 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. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-12-01 |
| Volume | volume14 |
| Issue | issue1 |
| Start Page | 29 |
| End Page | 37 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307477 |
| JaLCDOI | 10.18926/15779 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_15_2_107.pdf |
| Author | Totsuji Hiroo| Obata Takashi| Funahashi Takahiko| |
| Abstract | The dynamic form factor and the transverse part of the fluctuation spectrum of momentum density are analysed on the basis of the generalized Langevin equation. According to the indication of the result, numerical experiments are extended and it is shown that the transverse fluctuation spectrum contains two kinds of excitations. The frequency moment sum rules are discussed in relation to one of these excitations. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1981-03-30 |
| Volume | volume15 |
| Issue | issue2 |
| Start Page | 107 |
| End Page | 118 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307901 |
| JaLCDOI | 10.18926/15841 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_10_1_61.pdf |
| Author | School of Engineering, Okayama University| |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1975-07-01 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 61 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307517 |
| JaLCDOI | 10.18926/15810 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_16_2_59.pdf |
| Author | Hida M.| Maeda H.| Tanabe K.| Kamijo N.| Terauchi H.| |
| Abstract | The EXAFS spectroscopy equipment constructed from an asymmetrical cut flat monochromator and PSPC is applied to the structural determination of pure α-iron which has small difference (0.038nm) in the first and second nearest neighbour distance. The efficiency of the curve fitting method for the two shell model of known structure material (α-iron) is discussed, in addition to describing the details of the experimental procedure of our new type of spectrometer and of the EXAFS data analysis. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1982-03-29 |
| Volume | volume16 |
| Issue | issue2 |
| Start Page | 59 |
| End Page | 74 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307651 |
| JaLCDOI | 10.18926/15819 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_17_1_61.pdf |
| Author | Maeno Shiro| Nago Hiroshi| |
| Abstract | In this paper the liquefaction of sand bed under oscillating water pressure are treated as a basic study of the prevention works against the scouring around the hydraulic structures. The results of the former resurch show that the occurrence of the liquefaction depends on both properties of the oscillating water pressure and of the sand layer. Considering the latter properties, that is, the resistivity against the liquefaction increases with the increase of the permeability of the sand bed, we propose the displcement method as one of the prevention works, which is a method to displace the upper layer of the sand bed by the sand with large permeability. The effects of this method are investigated theoretically and experimentally. By the experimental study, it is shown that the proposed displacement method has the apparent effect to prevent the liquefaction. The experimental results are explained fairly well by the theoretical analysis based on the theory of the flow through the elastic porous media. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1983-02-25 |
| Volume | volume17 |
| Issue | issue1 |
| Start Page | 61 |
| End Page | 71 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| JaLCDOI | 10.18926/15673 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_4_57.pdf |
| Author | Takahashi Teruo| Kitamura Yoshiro| |
| Abstract | Although the stability of Newtonian liquid jet has been investigated experimentally and theoretically, many problems has remained unsolved. Especially, the stability of liquid jets in immiscible liquid systems has been little studied. Furthermore, one has to point out that the stability of jets may be influenced by the turbulence in the nozzle and the velocity profile. This work presents the experimental result about the effect of the nozzle length on the breakup length of liquid jets in the air and in the immiscible liquid, as the beginning of a systematic investigation of the influence by these factors on the breakup of jet. The dependence of the initial amplitude of surface disturbances on the nozzle geometry is presented for evaluating the effect of the nozzle length on the breakup length of laminar liquid jet in the air and in the immiscible liquid. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1969-09-01 |
| Volume | volume4 |
| Issue | issue1 |
| Start Page | 57 |
| End Page | 64 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307482 |
| JaLCDOI | 10.18926/15634 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_6_21.pdf |
| Author | Wada Tsutomu| Shimizu Akira| |
| Abstract | In this report, the effects of splitter position on the attached jet were experimentally investigated for the purpose of discussing the applicability of a usual mathematical model without splitter. As results, the followings were confirmed, (l) For the splitter distance shorter than the critical distance, the pressure in the bubble lowers and the jet radius of curvature shortens. (2) At the ratio L(s)/D=4~5, the switching control flow rate becomes maximum. And bordering this value, the effects of splitter position on the switching are quite conversely. For the splitter distance longer than the above value, the switching control flow rate decreases, as increasing the distance. (3) For the splitter distance of 1.5~2 times critical distance, the switching is almost never affected by the splitter. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1971-09-01 |
| Volume | volume6 |
| Issue | issue1 |
| Start Page | 21 |
| End Page | 25 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307823 |
| JaLCDOI | 10.18926/15657 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_8_1_25.pdf |
| Author | Wada Tsutomu| Shimizu Akira| Takagi Minoru| |
| Abstract | The effects of some geometries peculiar to the wallattachment fluidic devices on the attaching jet flow and the switching mechanism were experimentally made clear. And the propriety of the analytical mOdel, which has been used for the theoretical study of these devices, was investigated. The results can be summarized as follows: 1) The existing analytical model of the attaching jet flow is not applicable to the case of relatively short wall length of vent distance. 2) The attaching jet flow never detaches from a sufficiently long side wall with vent. 3) The switching mechanism of the vent type device is always the opposite wall switching. 4) From the viewpoint of the output characteristics of the device, the vent distance has a lower limit in relation to the vent width. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1973-07-20 |
| Volume | volume8 |
| Issue | issue1 |
| Start Page | 25 |
| End Page | 40 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307550 |
| JaLCDOI | 10.18926/15712 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_119.pdf |
| Author | Ohta, Mutsuo| Yamada, Masuo| Kanadani, Teruto| Sakakibara, Akira| |
| Abstract | The effects of the fluctuation of solute concentration on the process of aging in Al-10wt % Zn alloy were studied by measurements of the intensity of small-angle X-ray scattering and by electron microscopy. Specimen was quenched from a higher temperature(T(Ql), mainly 300℃) to an intermediate temperature (T(Q2), 110~230℃), held there for a time, quenched again into iced water and aged isothermally at 0℃ or 40℃. Results obtained are as follows: (1) When the specimen was held at T(Q2) for a sufficient time and aged at relatively high temperatue(e.g. Ihr at 125℃ and aged at 40℃), a two-step increasing of both resistivity and integrated intensity was found. (2) Each of the steps has characteristics of the formation of G.P. zones by the spinodal decomposition. (3) When the maximum resistivity(p(max)) takes a minimum, Size distribution of the G.P. zones, estimated from the difference between Guinier and Porod radii, is much broader than that at p(max) in the usual direct quenching. (4) When the holding time at T(Q2) is long enough, the size distribution at p(max) is as broad as that at p(max) in the usual case. (5) After a prolonged aging under the condition that P(max) takes minimum, G.P. zones grow markedly and become oblate ellipsoidal with a major axis of about 20nm. (6) These results are consistently understood in terms of the fluctuation of solute concentration at T(Q2) and the change in the concentration of vacancies during annealing at T(Q2). That is, it is considered that these results are due to the difference in aging behavior between the regions of relatively high concentration and the ones of low concentration induced by the fluctuation. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 119 |
| End Page | 132 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307931 |
| JaLCDOI | 10.18926/15709 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_95.pdf |
| Author | Ohta, Mutsuo| Kanadani, Teruto| Yamada, Masuo| Sakakibara, Akira| |
| Abstract | Aging process in Al-Zn alloys was studied by the measurements of the electrical resistivity when the alloy was quenched from a high temperature, about 300℃ (the first quenching temperature), to an intermediate temperature, between 110℃ and 230℃ (the second quenching temperature), held at this temperature for a time, quenched again into iced water and aged at a low temperature. Variation of the holding time at the second quenching temperature brings about the variation of the isothermal aging curves. Maximum resistivity of the isothermal aging curve, p(max) , decreases at first, passes a minimum and then increases to reach a stationary value as the holding time at the intermediate temperature increases. It is pointed out that this phenomenon is mainly due to the fluctuation of solute concentration and the vacancy concentration decreasing at the intermediate temperature. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 95 |
| End Page | 117 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307526 |
| JaLCDOI | 10.18926/15767 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_18_1_43.pdf |
| Author | Ohzuku Tsutomu| Hirai Taketsugu| |
| Abstract | An equation on the current-polarization voltage characteristics of single charge transfer redox reaction on a rotating disk electrode (RDE) was given and a curvefitting method to determine kinetic parameters from an observed polarization curve was proposed therefrom. The method was demonstrated for Fe(2+)/Fe(3+)redox reaction in acidic aqueous electrolyte on Pt-RDE and the limitation of the method was discussed. The extension of the method to multistep charge transfer reaction was also considered. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1984-03-30 |
| Volume | volume18 |
| Issue | issue1 |
| Start Page | 43 |
| End Page | 56 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307914 |
