JaLCDOI 10.18926/15735
FullText URL Mem_Sch_Eng_OU_14_1_9.pdf
Author Fujiwara Yasuo| Monobe Kazuo|
Abstract 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.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1979-12-01
Volume volume14
Issue issue1
Start Page 9
End Page 14
ISSN 0475-0071
language English
File Version publisher
NAID 120002307317
JaLCDOI 10.18926/15734
FullText URL Mem_Sch_Eng_OU_14_1_1.pdf
Author Yamashita Yuhiko| Monobe Kazuo|
Abstract 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.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1979-12-01
Volume volume14
Issue issue1
Start Page 1
End Page 7
ISSN 0475-0071
language English
File Version publisher
NAID 120002307641
JaLCDOI 10.18926/15733
FullText URL Mem_Sch_Eng_OU_12_129.pdf
Author Myojin Syo| Tatsuta Akira| Taka Yasuhisa| Asai Kazuhiko|
Abstract A statistical analysis is applied to find what states of "block" are dangerous from view point of traffic accident. Here, the block is defined to be an area surrounded by some major streets and is feeded by a minor street network. The accidents under study are those which occur in the whole minor street network. They are grouped into three kinds; pedestrian, vehicle and the gross accidents. And each is classified to three types according to the place where the accident occurs. At the beginning 22 variables are assumed to state a certain relationship of some states of the block with the occurrences of accidents and 12 variables are found significant finally through factor analysis. Further examination has reached several key variables that migth have something significant to cause traffic accidents in the block. The key ones are the number of lanes of street and the number of legs of intersection, especially nearly 2 lanes street and 3-leg intersection, respectively. The case study was carried out on 26 blocks sampled from Osaka City.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 129
End Page 139
ISSN 0475-0071
language English
File Version publisher
NAID 120002307311
JaLCDOI 10.18926/15732
FullText URL Mem_Sch_Eng_OU_13_249.pdf
Author Yamamoto Kyoji|
Abstract The asymptotic theory of Rayleigh shear flow for large values of time is developed on the basis of the linearized Boltzmann-Krook equation. Asymptotic equations for mean velocity outside the Knudsen layer are obtained by employing the Hilbert expansion. Slip boundary conditions are derived from the analysis of the Knudsen layer adjacent to the wall. A solution of the asymptotic equation is obtained under the slip boundary condition and zero initial condition. Discussions are also made of the flow induced by a slowly oscillating flat plate.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1979-03-05
Volume volume13
Start Page 249
End Page 258
ISSN 0475-0071
language English
File Version publisher
NAID 120002307963
JaLCDOI 10.18926/15731
FullText URL Mem_Sch_Eng_OU_12_97.pdf
Author Kono Iichiro| Nishigaki Makoto|
Abstract The solutions of unsteady phreatic flow toward a partially penetrating well in an aquifer of finite thickness are described. Firstly the solution for a confined aquifer is shown. In this case,three methods of analyzing field data with partially penetrating well are given, that is, "Log-Log Method, Log-Log Distance Drawdown Method and Jacob's Method Ajusted for Partial Penetration". By using these methods the hydraulic conductivities and the specific storage of the aquifer may be determined. Secondly the solution for an,unconfined aquifer is shown. In this case, also two methods of analyzing field data with partially penetrating well are given. By using these methods, the anisotropic permeability and the storage coefficient (effective porosity) of the aquifer may be determined. Moreover in each case, the effects of partial penetration are discussed and the limits of adapting the Theis' and Jacob's methods are setted. From these analytic results, some cosiderations are added to determine the anisotropy of permeability and to evaluate the storage coefficient.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 97
End Page 128
ISSN 0475-0071
language English
File Version publisher
NAID 120002307830
JaLCDOI 10.18926/15730
FullText URL Mem_Sch_Eng_OU_12_89.pdf
Author Totsuji Hiroo|
Abstract The pair correlation function and the correlation energy density of two-dimensional electron liquids are calculated on the basis of the Salpeter's Debye-chain type expansion. When the two-dimensional plasma parameter (£=2πne4T-2) is small, the expansion to the first order gives the correlation energy to the order of (£21n£). It is shown that experimental results in the domain (£<0.5) can be reproduced by taking into account the first and the second order terms in this expansion.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 89
End Page 96
ISSN 0475-0071
language English
File Version publisher
NAID 120002307196
JaLCDOI 10.18926/15729
FullText URL Mem_Sch_Eng_OU_13_239.pdf
Author Taniguchi Takeo|
Abstract In this paper the minimum fill-in problem which arises at the application of the sparse matrix method for linear sparse systems is discussed from the graphtheoretic viewpoint and the author gives some results which can be directly introduced in the design of, so called, the optimal elimination ordering algorithm which gives the minimum fill-in(the number of zeros in coefficient matrix which become non-zero during the elimination process). Through this investigation only graphs are treated instead of the coefficient matrices for linear systems, and the elimination process for a matrix is equivalated to the vertx eliminations for the graph. Then, the results by the theoretical investigation are summarized as following: 1. Optimal elimination for each subgraph which is subdivided appropriately from whole graph leads to the global optimum. 2. In each subgraph there are only two kind of eliminations. Furthermore, some numerical experiments show the characteristics of the subset of vertices, which subdivide a subgraph from the residual.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1979-03-05
Volume volume13
Start Page 239
End Page 248
ISSN 0475-0071
language English
File Version publisher
NAID 120002307617
JaLCDOI 10.18926/15728
FullText URL Mem_Sch_Eng_OU_13_225.pdf
Author Kaneda Masahiro| Shinji Hiroshi| Aoyama Mikio|
Abstract This paper deals with the adaptive observer which estimates the states and parameters of unknown system. It is shown that the adaptive observer problem is reduced to the identification of the transformation matrix for an arbitrary designable observer. Moreover, the adaptive process of the unknown parameters is reduced to the linear optimal regulator problem. As the result, a new method is presented to obtain an appropriate adaptive process with good insight. And, in this identification, a linear filter is found to be also useful against noises in input-output data. To achieve high accuracy, a particular nonlinear filtering can improve SN ratio only in the direction of the unknown vector. Even if SN ratio of input-output data has zero dB, sufficient accuracy can be accomplished within suitable correction time. This design algorithm seems to be rather straightforward and practical. Since input sequence is required to be only sufficiently general, the method is applicable to on-line identification also.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1979-03-05
Volume volume13
Start Page 225
End Page 238
ISSN 0475-0071
language English
File Version publisher
NAID 120002307984
JaLCDOI 10.18926/15727
FullText URL Mem_Sch_Eng_OU_12_77.pdf
Author Ohta, Mutsuo| Kobayashi, Toshinori| Sakakibara, Akira|
Abstract The clustering phenomenon was observed when dilute Al-Zn alloys were annealed at temperatures higher than the solvus of the G.P.zones. In this report the apparent activation energy for clustering is estimated and compared with the experimental results. The estimated value of the apparent activation energy for clustering in several Al-Zn alloys comes to 0.51 eV, which is larger than the effective migration energy 0.43 eV of Zn atoms in Al-Zn alloys.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 77
End Page 88
ISSN 0475-0071
language English
File Version publisher
NAID 120002307178
JaLCDOI 10.18926/15726
FullText URL Mem_Sch_Eng_OU_13_219.pdf
Author Totsuji Hiroo| Kakeya Hideyuki|
Abstract The dynamic form factor and the dispersion relation of the plasma oscillation of two-dimensional classical systems of electrons with ordinary Coulomb interaction are obtained by numerical experiments in the domain of the plasma parameter 2.24≤√=(πn)(1/2)e(2)/T≤70.7, where n, e, and T are the areal number density, the electronic charge, and the temperature in energy units, respectively.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1979-03-05
Volume volume13
Start Page 219
End Page 224
ISSN 0475-0071
language English
File Version publisher
NAID 120002307942
JaLCDOI 10.18926/15725
FullText URL Mem_Sch_Eng_OU_12_59.pdf
Author Ohta, Mutsuo| Kanadani, Teruto| Sakakibara, Akira|
Abstract Several Al-Zn alloys containing 0.041-4.4 at % Zn were studied by means of measurements of electrical resistivity. The results obtained are as follows : (1) The electrical resistivity increases when the specimen is annealed at temperatures higher than the solvus temperature of the G.P. zones. The increase of the resistivity is due to the formation of fluctuation. (2) The electrical resistivity of the specimen containing fluctuation is dependent upon annealing temperature only and independent of quenching temperature. (3) The fluctuation is formed in very dilute alloys as 0.041 at % Zn at temperatures higher than the solvus temperature of the G.P. zones. (4) The formation energy of vacancy and the migration energy of the Zn atom in the alloys determined by the formation process of fluctuation are in good agreement with those by the formation process of G.P. zones. (5) In spite of the result (4), it seems that the fluctuation is not the same as the small G.P. zones which are observed in the early stage of aging.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 59
End Page 75
ISSN 0475-0071
language English
File Version publisher
NAID 120002307636
JaLCDOI 10.18926/15724
FullText URL Mem_Sch_Eng_OU_13_209.pdf
Author Totsuji Hiroo|
Abstract Exact lower bounds are given for thermodynamic quantities of ionic mixtures in the uniform background in d dimensions with three-dimensional (1/r) Coulomb interaction (d=2 and 3) and with d-dimensional Coulomb interaction (d=1, 2, and 3). It is shown that these lower bounds improve upon known ones and give values close to experimental results which are available in the case of d=3.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1979-03-05
Volume volume13
Start Page 209
End Page 218
ISSN 0475-0071
language English
File Version publisher
NAID 120002307762
JaLCDOI 10.18926/15723
FullText URL Mem_Sch_Eng_OU_13_195.pdf
Author Sano, Hiroya| Koga, Ryuji| Tanada Yoshihiro| Kosaka, Megumi|
Abstract The maximally attainable accuracy of an airpollution monitoring system is investigated. The system is composed of a tunable pulsed dye laser as the light source, photodiodes as the opto-electric converter and a low noise electronic signal processor specifically designed by the authors. The extreme value of the accuracy is given in terms of the standard deviation of the attenuation. The value is 3.4×10(-4)[Nep√(pulse number)] for an averaged value for multiple laser shots. Also the wavelength reproduceability of a dye laser was examined, which resulted in that a computer should take a part in the wavelength control in order that this method should be feasible.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1979-03-05
Volume volume13
Start Page 195
End Page 207
ISSN 0475-0071
language English
File Version publisher
NAID 120002307857
JaLCDOI 10.18926/15722
FullText URL Mem_Sch_Eng_OU_13_181.pdf
Author Sano, Hiroya| Koga, Ryuji| Tanada, Yoshihiro| Kosaka, Megumi|
Abstract This report deals with a notion of adjoint spectrum which is applicable to air-pollution monitoring by using pulsed lasers. Both Raman and absorption spectra of multiple gas complex are linear combinations of the spectra, each of which is specific to a gas species and its magnitude is proportional to the density. An extended formulation of the method of least squares is made in terms of a new notion, adjoint spectra, which visualizes the structure of the numerical filter. Applications of the derived numerical filters to the two methods are shown and features are described about the synthesized filters.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1979-03-05
Volume volume13
Start Page 181
End Page 193
ISSN 0475-0071
language English
File Version publisher
NAID 120002307476
JaLCDOI 10.18926/15721
FullText URL Mem_Sch_Eng_OU_12_53.pdf
Author Fujitsuka Takeshi| Agusa Toru|
Abstract In recent years, the development of a high power transistor element is proceeding. A high power inverter circuit using power transistors are finding a good number of applications in induction heating and melting. Turn off time of power transistors occupies 5-lOμs of switching characteristics. A driving method to give base inputs for a half period is widely used for a inverter circuit. But this method has the following defects, the short-circuit current flows through two transistors because the other pair transistors turn on before one pair transistors turn off. So the switching loss is increased, the maximum output and the efficiency are decreased. In this paper, a driving method to give base inputs for the less period as compared with a half period is discussed. Using this method, the foregoing defects is lost and the driving frequency is able to become higher. In addition, it become clear that the square waveform output is given using this method in the case of R-L load.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 53
End Page 58
ISSN 0475-0071
language English
File Version publisher
NAID 120002307552
JaLCDOI 10.18926/15720
FullText URL Mem_Sch_Eng_OU_12_45.pdf
Author Himei Toyoji| Nakanishi Senichiro| Funabiki Shigeyuki|
Abstract In this paper, an AC chopper circuit, using a power transistor, is described which chops the AC voltage with a commercial frequency. The circuit is composed of a diode bridge and a power transistor in series with a load and capable of adjusting the switching frequency, fc, and the time ratio, T=ton/(ton+toff). The switching frequency and the time ratio of the AC chopper circuit depend on switching-times, that is, delay time, rise time, carrier storage time and fall time, especially in the high frequency. The upper limit of the switching frequency (about 150kHz) and the output characteristics of the circuit are investigated.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 45
End Page 52
ISSN 0475-0071
language English
File Version publisher
NAID 120002307334
JaLCDOI 10.18926/15719
FullText URL Mem_Sch_Eng_OU_13_163.pdf
Author Tanada Yoshihiro| Sano Hiroya|
Abstract A new waveform analyzer based on the Walsh transform is developed and is applied to a real-time filtering of fast pulse signals, and the linear filterings of time signals through the Walsh transform is discussed. The analyzer converts a solitary waveform during 16 μs into the 16 Walsh amplitude spectra in a hybrid manner: it has the sequency band from 62.5 kzps to 500 kzps. The spectra are parallelly held during 16 μs by analog integrators, while serially displayed by the CRT, and one of them is digitally read out. The spectra of the test waves are measured within the error rate of several per cent. The analyzer is applied to the correlative detection of the photoelectric pulse signals in a gasspectroscopic system using a pulse laser, and there composes the matched filter, which is useful for measuring the signals superposed by Gaussian noises with a high accuracy. For the real-time filtering of fast signals, the arithmetic convolution and the frequency power spectra are approximated using the complex Walsh transform. These approximations are of practical use in 16 or 32 dimensions. Then, the matched filters for pulse peaking are given by the approximate convolution and by the dyadic convolution.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1979-03-05
Volume volume13
Start Page 163
End Page 180
ISSN 0475-0071
language English
File Version publisher
NAID 120002307519
JaLCDOI 10.18926/15717
FullText URL Mem_Sch_Eng_OU_13_153.pdf
Author Fukui, Kiyoshi| Nogi, Shigeji| Yamada, Masuo| Sakakibara, Akira|
Abstract A unified treatment of injection and mutual phase locking phenomena in microwave oscillators coupled by a network characterized by a Y-matrix is presented. Under certain simplifying assumptions, steady state solutions such as locking frequency and oscillation phase relation are given with emphasis placed on the coupling-network dependence of locking bandwidth. Also, some examples of locking system specified by y(21)=0, Y(21)= Y(12) and y21= -Y12 are briefly discussed.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1979-03-05
Volume volume13
Start Page 153
End Page 162
ISSN 0475-0071
language English
File Version publisher
NAID 120002307532
JaLCDOI 10.18926/15716
FullText URL Mem_Sch_Eng_OU_12_29.pdf
Author Yamamoto Tatsuma| Yamamoto Yoshitake| Nishida Hideki| Yasuhara Kiyotaka|
Abstract The distributed circuit properties based on pores in the etched aluminum oxide film of the electrolytic capacitor have been analysed by the mathematical equation. This paper proposes the selection and the determining method of the parameters appearing in the analysis.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 29
End Page 36
ISSN 0475-0071
language English
File Version publisher
NAID 120002307968
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