result 19474 件
| JaLCDOI | 10.18926/15715 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_133.pdf |
| Author | Ohta, Mutsuo| Kanadani, Teruto| Yamada, Masuo| Sakakibara, Akira| |
| Abstract | Aging and reversion in dilute Al-Ag alloys are studied by means of the measurements of electrical resistivity. Results obtained are as follows: 1) Increase in the as-quenched resistivity is found for a low quenching temperature. This increase may be due to the fluctuation of solute concentration at the quenching temperature. 2) When the fluctuation exists in the alloy, the aging rate becomes slow and the maximum resistivity in the isothermal aging curve becomes small as the vacancyconcentration becomes low. The maximum resistivity becomes large again when the vacancy concentration becomes further lower, and finally the maximum does not appear. 3) These behaviors are explained in terms of the difference in the rate of growth of the G.P. zones in the regions of higher and lower solute concentration induced by the fluctuation and in terms of the change of this difference with vacancy concentration. 4) G.P. zones may be formed by the spinodal decomposition with indefinite surfaces at first, grown to larger ones with difinite surfaces and changed to ordered nzones in the alloy. 5) It is confirmed that G.P. zones are formed by the nucleation-and-growth mechanism also in Al-Ag alloys above the spinodal temperature. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 133 |
| End Page | 152 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307468 |
| JaLCDOI | 10.18926/15714 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_12_23.pdf |
| Author | Yamashita Yuhiko| Monobe Kazuo| |
| Abstract | A new realistic, structural model is proposed for the glassy solid state of poly(ethylene terephthalate) (PET). The model is considered basing on crystallization behaviors from the glassy state of PET, and in particular including the evidence from the estimation of chain folding energy in this report. When PET is quenched from its melt into the glassy state, irregular folds with lower conformational energy remain in glassy structure and disturb the three dimensional arrangement of the chains connected with the folds. In conclusion, we suggested that the structure of glassy PET is not in amorphous state which is represented by the interpenetrating random coil model, but in frozen metastable state which can be approached from the chain folded structure of polymer crystals. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1978-02-25 |
| Volume | volume12 |
| Start Page | 23 |
| End Page | 28 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307771 |
| JaLCDOI | 10.18926/15713 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_11_2_51.pdf |
| Author | Inouye Hiroshi| |
| Abstract | In this paper some computational methods of traffic assignment are proposed. At first solutions of traffic assignment by the equal travel times principle used nonlinear programmings are showed. They are a method to approximate by a quadratic programming, a method to use the SUMT transformation, a method to apply Rosen's gradient projection method and a method to apply the conjugate gradient projection method. Through a computational example the efficiency of them are compared. To decide route flows uniquely in traffic assignment by the equal travel times principle, a method requesting route flows such that the joint probability is a maximum under supposed a priori probabilities is proposed. In case of a traffic assignment in a large scale road network, it is significant to improve the efficiency of route searches. For this purpose a technique of minimum time route search by division of a network is proposed. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1977-01-25 |
| Volume | volume11 |
| Issue | issue2 |
| Start Page | 51 |
| End Page | 71 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307829 |
| 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 | 10.18926/15710 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_11_2_27.pdf |
| Author | Nago Hiroshi| |
| Abstract | In this paper the influence of a vertical lip upon the contraction coefficients of underflow gates is discussed. The coefficients of inclined gates with a vertical lip are investigated theoretically by using the method of conformal mapping. Solutions are obtained numerically for several values of the inclination of gate bottom. Theoretical solutions show that;as the length of a lip increases, the coefficient rapidly decreases from the value for the inclined gate, and when the length becomes of the order of a gate openning,it takes a value to be nearly equal to that for a vertical gate. These theoretical results are verified by experiments. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1977-01-25 |
| Volume | volume11 |
| Issue | issue2 |
| Start Page | 27 |
| End Page | 36 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307779 |
| 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 | 10.18926/15706 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_83.pdf |
| Author | Akagi Fumio| Osaki Hirokazu| Kikuchi Susumu| |
| Abstract | To assign work elements to the work stations in an assembly or manufacturing line, various computer programs have been developed and used. And it does that the number of stations or the cycle time is even given. But in practice it is desirable to obtain the assignment which shows the highest efficiency of line balancing under all possible combinations of the number of stations and the cycle time. Therefore we propose a computer program of the assignment method in which the efficiency of line balancing, Ebb and the number of stations, NN are regarded as variables. In this method the minimum value (EEb) of efficiency and the constant term (d) by which Ebb is reduced are given previously. And for any COmbination of Ebb (EE |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 83 |
| End Page | 93 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307716 |
| JaLCDOI | 10.18926/15705 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_11_1_31.pdf |
| Author | Inouye Hiroshi| |
| Abstract | In this paper we deal with traffic behaviours on a section of highway including an on-ramp by means of queuing theory. It is the purpose of this paper to provide the adequate capacity for highway on-ramps, which is useful for the design of on-ramps and the traffic control of highway. The highway on-ramp merging is modeled as a queue and the system is solved. Then the maximum possible flows for merging from an on-ramp is obtained in a form of an function of through lane flows. The traffic capacity of an on-ramp is estimated from the relation between the average waiting time before merging and the incoming flow from an on-ramp, which is induced by the theory of queues. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1976-07-20 |
| Volume | volume11 |
| Issue | issue1 |
| Start Page | 31 |
| End Page | 43 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307164 |
| JaLCDOI | 10.18926/15704 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_65.pdf |
| Author | Ushio Junichi| Osaki Hirokazu| Kikuchi Susumu| |
| Abstract | We try to evaluate the manual work numerically from a point of view of the homogeneousness and the simultaneousness of both hands using the results of the micromotion study. The weighted coefficient and the balance index are used to evaluate the homogeneousness of both hands. And the simultaneous index is used to evaluate the simultaneous movement of both hands. It is necessary to make a program in order to use efficiently the method to calculate the indexes or the coefficients. Therefore the computer program of these methods is mentioned in this paper. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 65 |
| End Page | 81 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307987 |
| JaLCDOI | 10.18926/15703 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_11_1_19.pdf |
| Author | Koga, Ryuji| |
| Abstract | An optimal control is giyen for regulating power distribution in a nuclear power reactor which has cylindrical geometry. The space dependence of the system is described by expanding space depenident variables by Helmholtz modes. Results are obtained through the principle of optimality and are described by the Riccati-type algebraic equation that the optimal feedback coefficients should satisfy. Use of an integral equation as the system equation makes it possible to deal with actual controlling apparatuses: control rods or rod clusters. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1976-07-20 |
| Volume | volume11 |
| Issue | issue1 |
| Start Page | 19 |
| End Page | 30 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307572 |
| JaLCDOI | 10.18926/15702 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_53.pdf |
| Author | Funabiki Shigeyuki| Nakanishi Senichiro| Himei Toyoji| |
| Abstract | An ac chopper circuit, which chops an ac voltage in a complete cycle for any lagging reactive load, is devised. The circuit is constructed of two ac-switches composed of power transistors and diodes. The load voltage is smoothly controlled by varying the time ratio of ac-switch. Transistors operate in a highfrequency chopping mode, thereby the ripples of the source current and the load current are easily filtered. Furthermore the input power factor of this model is better than that of the thyristor phase control circuit. In this paper, the construction and the driving method of this model are described. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 53 |
| End Page | 64 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307832 |
| JaLCDOI | 10.18926/15701 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_11_1_7.pdf |
| Author | Ishii Tadao| Doi Mitsuharu| |
| Abstract | An investigation was made of the anomalous electric field in its various aspects in n-type InSb subjected to strong magnetic field at 77K and 273K, which lead to the conclusion that no open contradiction arose between a part of the present observations and the predictions attainable from Yoshida's model of semimetals. There remained, however, the other part of the experimental results unexplained, being rather natural since an inner property of indium antimonide does not seem so simple comparing with the compensated metals, bismuth and antimony. Especially as for the mechanism of an inversion phenomenon of the polarity of a negative anomalous field at a critical pulse current, we have no available theory to explain at present stage. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1976-07-20 |
| Volume | volume11 |
| Issue | issue1 |
| Start Page | 7 |
| End Page | 18 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307614 |
| JaLCDOI | 10.18926/15700 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_45.pdf |
| Author | Fujitsuka Takeshi| Agusa Toru| |
| Abstract | In this paper, the steady state operations of the squarewave inverter circuit with a series R-L load are discussed. The circuit consists of transistors and feedback diodes. The basic equation is derived from its equivalent circuit. Solving the basic equation with steady state conditions, the instaneous value of the load current i is derived. The period t(2) for which the current flows from the supply to the load and the period t(l) for which the current feedbacks through diodes from the load to the supply are calculated from (i), and the ratio of t(l) to t(2) is illustrated using power factor of fundamental wave, pf, as a variable. The ratios of transistor mean current I(tr), diode mean current I(D), supply mean current I(s) to the load current I are illustrated using pf as a variable, too. In result, each current ratios to I is shown in simple expressione. The load current can be calculated simply using the coefficient reading off the figure. In addition, it becomes clear from the figure that the load current is scarcely influenced by the harmonic voltage in less than 0.8 of pf. The ratio t(2)/(t(1)+t(2)) calculated in squarewave voltage, shows the limit of pulse width control whose out put voltage is the squarewave. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 45 |
| End Page | 52 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307473 |
| JaLCDOI | 10.18926/15697 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_5_61.pdf |
| Author | Misaki Takayoshi| Okamoto Takuji| Yamamoto Hideki| |
| Abstract | An asynchronous delay line for PAM signal having controlled delay capability is proposed. The delay line in a cascaded chain of identical memory cells. Each sample of the sequence of the input PAM signals passes or is shifted in particular cell depending on whether the succeeding cell is empty or not. A cell is composed of two memory capacitors with the peripheral control circuits. In this paper, especially, an example of the circuit for cell is shown and its several characteristics are discussed. At the end, some experimental results are given. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1970-09-01 |
| Volume | volume5 |
| Issue | issue1 |
| Start Page | 61 |
| End Page | 66 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307866 |
| JaLCDOI | 10.18926/15696 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_1.pdf |
| Author | Tanaka Yutaka| |
| Abstract | In this paper, is proposed a calculating method for the simulation of oscillatory combustion state, and comparisons between estimation results and experimental ones are carried out. With respect to the effects of geometric dimensions of combustion system, and of fueland air-flow rate conditions on characteristics such as an amplitude of oscillation, its fluctuation, and a frequency, a theoretical analysis presents a correct estimation of the phenomena. By use of this analysis, it becomes possible exactly to estimate the changes which take place in the combustion system. On the basis of the quantitative feature of the theoretical results, the influences of the factors such as ignition lag, wall temperature ratio, and heat transmission on the combustion oscillation are studied. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 1 |
| End Page | 24 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307496 |
| JaLCDOI | 10.18926/15695 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_10_2_113.pdf |
| Author | Kono Ichiro| Sellmeijer J.B.| |
| Abstract | This paper deals with the groundwater flow in a semi-confined aquifer causing the phenomena of consolidation and free surface lowering. Since the main effect of consolidation has taken place before noticeable lowering of the free surface, one may solve each phenomenon on its own. The real solution may be obtained by the principle of superposition. However, the solution for lowering the free surface is delayed due to the cosolidation by a certain timelapse, depending on the placecoordinates. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1976-01-27 |
| Volume | volume10 |
| Issue | issue2 |
| Start Page | 113 |
| End Page | 136 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307163 |
| JaLCDOI | 10.18926/15693 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_10_2_81.pdf |
| Author | Sakakibara, Akira| |
| Abstract | To acquire information on the interaction between oxygen molecules in solid phase, studies have been carried out on the magnetic properties of solid oxygen, oxygen-argon and oxygen-fluorine. Review of the studies on the interaction between oxygen molecules is cited. Magnetic susceptibility was measured by the Faraday method as a function of temperature from 12 K to the melting point of them. Pure oxygen both in α and β phase indicates paramagnetism corresponding to long-range antiferromagnetic order. Oxygen -argon mixtures of 92~66 mol% oxygen content indicate large susceptibility corresponding to δ phase, which can be interpreted in terms of the cluster of oxygen molecules in trimer. Small paramagnetism was found for the oxygenfluorine mixture even as dilute as 10 mol% oxygen content, which may be due to the strong antiferromagnetic interaction. This can be interpreted in terms of super-exchange interaction between oxygen molecules via fluorine molecule. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1976-01-27 |
| Volume | volume10 |
| Issue | issue2 |
| Start Page | 81 |
| End Page | 111 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307359 |
| 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 | 10.18926/15690 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_10_2_55.pdf |
| Author | Nakata Takayoshi| Ishihara Yoshiyuki| Matsubara Kazunori| Nakano Masanori| |
| Abstract | A new method have been developed based upon analogue-to-digital conversion techniques and memories. The method involves the scaling of operating frequency from "real" to "optimum" for the power loss measurement. The advantages of using this techniques are as follows: (1) extreme availability at lower frequency region, (2) high accuracy and high stability, (3) simple measuring procedure, (4) digital indication. This method can be measured the power losses over the frequency range 0.1Hz to 1kHz for magnetic circuit and d.c. to 1kHz in such a purely resistive circuit. We estimate the accuracy of this core loss measuring system within 1.0% over all these frequency range. Using this system, specific core losses of the various grades of silicon iron have been measured in the frequency range 0.1Hz to 200Hz. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1976-01-27 |
| Volume | volume10 |
| Issue | issue2 |
| Start Page | 55 |
| End Page | 61 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307969 |
| JaLCDOI | 10.18926/15688 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_10_2_45.pdf |
| Author | Himei Toyoji| Nakanishi Senichiro| Komatubara Hitoshi| Kawata Sigeo| Onishi Fujio| Tabuchi Takashi| |
| Abstract | When a transformer is energized, the inrush of abnormally high magnetizing current may be noted for a short time until normal flux conditions are established. This may cause the failure of a protective relay, so many preventives are usually accepted for the purpose of normal relay performance. The authors, instead, now have tried to control the inrush current itself, by means of the soft starting method using two reverse parallel thyristors. In this paper, the method to control the inrush current itself, is presented by the soft-starting method using thyristors. The experimental results of this Method verifies the good controlability of the transient magnetic flux of a transformer and then the availability of the control of magnetizing inrush current in the cases of a single phase connection and a three phase one. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1976-01-27 |
| Volume | volume10 |
| Issue | issue2 |
| Start Page | 45 |
| End Page | 54 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307871 |
