JaLCDOI 10.18926/15493
FullText URL Mem_Fac_Eng_OU_24_2_17.pdf
Author Konishi, Tadataka| Baba, Mitsuru|
Abstract Pressure distribution has been measured and analyzed to clarify the fundamental characteristics of "continuous oil-film" formed in a transparent journal bearing, into which oil in general use is supplied. Measured pressure mostly shows quasi-Sommerfeld distribution, which is characterized by downstream shift of pressure profile and underdevelopment of pressure trough compared with Sommerfeld distribution for perfect oil-film. Sommerfeld distribution is approximately observed only under limited conditions : low eccentricity and low speed. Quasi-Sommerfeld state is rather common in "continuous oil-film", unruptured film formed by using practical lubricants, than Sommerfeld state. Continuous oil-film is accompanied by fine bubbles and is controlled by the growing up or down of the bubbles.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-03-29
Volume volume24
Issue issue2
Start Page 17
End Page 30
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307431
JaLCDOI 10.18926/15491
FullText URL Mem_Fac_Eng_OU_24_2_11.pdf
Author Sakakibara, Akira| Kanadani, Teruto|
Abstract Aging behavior of Al-0.23mass % Si alloy was studied by measurements of elecrical resistivity. Resistvity maximum was observed in the aging curves at 273K after quenching from various temperatures. Appearance of maximum and its dependence on the quenching temperature were attributed to the formation of GP zones. Even in a more dilute alloy as 0.01mass % Si, the maximum of resistivity was also recognized.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-03-29
Volume volume24
Issue issue2
Start Page 11
End Page 16
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307615
JaLCDOI 10.18926/15490
FullText URL Mem_Fac_Eng_OU_25_1_51.pdf
Author Totsuji, Hiroo|
Abstract The superconductivity proximity effect in the dirty limit is revisited and equations and boundary conditions are obtained for the case of inhomogeneous media with continuously varying characteristic parameters.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-12-14
Volume volume25
Issue issue1
Start Page 51
End Page 57
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307188
JaLCDOI 10.18926/15487
FullText URL Mem_Fac_Eng_OU_24_1_135.pdf
Author Taniguhi, Takeo| Suetsugu, Tsuyoshi| Iwasaki Masaki|
Abstract This paper describes the numerical simulation method of the multi-crack propagation behaviour which appear in a part of civil engineering structures with complex geometrical configuration like steel bridges. Proposed method can treat the interaction of several cracks which locate in a short distance each other, and the process of their growth can be grasped. The method is based on the finite element method, and the linear fracture mechanics is assumed. Proposed method includes following tools for the simulation of the crack propagation behaviour: Automatic Mesh Generators for 3-D, 2-D structural analysis, and 2-D crack propagation analysis, Multi-level Structural Analysis Technique, Estimation Method of the crack growth and the angle of cracks and the modelling method of traffic loadings. The validity of the method is investigated by comparing the result to the experimental one.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 135
End Page 152
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307854
JaLCDOI 10.18926/15485
FullText URL Mem_Fac_Eng_OU_24_1_115.pdf
Author Abe, Hirofumi| Nogata Mikio|
Abstract The rapid economic growth of Japan in the postwar period has brought about the over-concentration of activities in a few large cities, and local regions have been losing their economic vitality due to the regional differentials and the population loss. Regional development planning in Japan has sought to achieve a balanced growth of the nation through the development of industries in local regions. This paper aims to examine the regional structure of manufacturing industries in the postwar period and to identify its current problems. Three methods, namely the analysis of coefficient of variation, the rateshare analysis and the shift-share analysis are applied using employment data of manufacturing industries for the years 1955 to 1985. Findings show that while the employment of manufacturing industries has been markedly decentralized from metropolitan to local regions, the disparities in growth rates still exist among regions.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 115
End Page 133
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307659
JaLCDOI 10.18926/15484
FullText URL Mem_Fac_Eng_OU_25_1_15.pdf
Author Sakakibara, Akira| Kanadani, Teruto|
Abstract Aging of Al-lmass % Ag alloy at 273K after quenching under various conditions was studied by measurement of electrical resistivity. Scattering of the quasi-equilibrium value of resistivity (p(e)) was not random but closely related to the as-quenched value (p(o)); P(e) increased with increasing p(o)' When the quenching temperature (T(q)) was lower than or equal to 773K, the state at p(e) was controlled substantially by the concentration of quenched vacancy. On the other hand, when T(q)>823K, GP zones formed during quenching played an important role, instead of quenched vacancies, in determining the state.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-12-14
Volume volume25
Issue issue1
Start Page 15
End Page 21
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307255
JaLCDOI 10.18926/15482
FullText URL Mem_Fac_Eng_OU_24_1_93.pdf
Author Totsuji, Hiroo| Hatatani, Teruki|
Abstract Propagation of charged carriers in semiconductor superlattices is analyzed on the basis of the effective mass approximation with appropriate boundary conditions at heterojunctions taken into account. Applying the finite element method, clarified are the effects of details of the potential profile, such as linear and smooth gradings and random fluctuations, on characteristics of superlattices which are expected to work as collector barriers and energy filters in electronic devices.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 93
End Page 105
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307513
JaLCDOI 10.18926/15481
FullText URL Mem_Fac_Eng_OU_24_1_81.pdf
Author Wada, Osami|
Abstract Are calculated the radiation characteristics of two types of primary-feed waveguides of millimeter wave quasi-optical antennas, which transform circular TE(On) mode into a linearly polarized beam. These antennas are utilized for heating and diagnostics of fusion plasma. Analysis is based on the Huygens-Fresnel principle, which takes the diffraction effect into account. For Convenience in analysis, a feed waveguide is divided into two sections, an uniform waveguide section and a visor section. Assuming that the diameter of the waveguide is several times as large as the wavelength and that the structure of the visor is open, the radiation field is approximated by superposition of direct radiation, and first and second reflection on the visor. Numerical results are presented and compared with experimental results. In these types of waveguides, the shadow section on the visor has a great influence on the radiation field. The results of calculation show that the length of the visor should be longer than that obtained by the geometrical optics, and the longer visor reduces the side-lobe level in the direction of the waveguide axis. The results agree well with those in experiments.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 81
End Page 92
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307974
JaLCDOI 10.18926/15478
FullText URL Mem_Fac_Eng_OU_23_2_45.pdf
Author Taniguchi, Takeo| Fujiwara, Kohji|
Abstract This paper includes a solver for a large sparse set of linear algebraic equations which are obtained by the application of the finite element method to static structural problems. Proposed method is a modification of Robust Incomplete Choleski-Conjugate Gradient Method, which belongs to Preconditioned Conjugate Gradient Method suitable for supercomputers. Through a number of numerical experiments the authors show that Robust Incomplete Choleski-Conjugate Gradient Method sometimes fails in to obtain the solutions, secondly they clarify the reason of the failures from the theoretical viewpoint, and finally they propose a modification of the robust method by the introduction of the theoretical result. Proposed method is as effective as the original, and it can overcome the demerit of Robust Method which is clarified through numerical experiments.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-03-30
Volume volume23
Issue issue2
Start Page 45
End Page 55
ISSN 0475-0071
language 日本語
File Version publisher
NAID 120002307820
JaLCDOI 10.18926/15477
FullText URL Mem_Fac_Eng_OU_23_2_33.pdf
Author Ishihara Yuji| Yamamoto, Kyoji|
Abstract This paper deals with the low Mach numbers flow of a rarefied vapour past a liquid sphere accompanied with condensation and evaporation at its surface. The linearized Bhatnager-Gross-Krook(B-G-K} equation is used for the analysis, and from it the integral equations of the density, temperature and flow velocities are derived. These integral equations are solved numerically over a wide range of the Knudsen number covering from the slip flow to the nearly free molecular flow. The drag on the sphere is also calculated and is compared with that of previous work.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-03-30
Volume volume23
Issue issue2
Start Page 33
End Page 44
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307401
JaLCDOI 10.18926/15475
FullText URL Mem_Fac_Eng_OU_23_2_21.pdf
Author Myojin Sho| Yamada Masahito| Fujii Naoto|
Abstract Diversion model and disaggregate behavioral model of logit type are adopted as aggregate and disaggregate estimates, respectively. Diversion model is assumed as a binary choice process including diversion ratio function at each step in the process. Diversion ratio is assumed as a function of generalized-travel-time ratio. The function is identified with each of the two steps of diversion; diverson from rail and bus to car at first and from the rest undiverted to bus at second. The data used are those on inter-regional occupational person trips. Each function are found enough and/or critically significant in the statistical sense. At the begginning, sixteen characteristics variables are enrolled in disaggregate model, which are identified by use of the above data. Six variables are reached finally and are all reasonable. A brief comparison of goodness of fit to the data are made between two models.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-03-30
Volume volume23
Issue issue2
Start Page 21
End Page 32
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307168
JaLCDOI 10.18926/15472
FullText URL Mem_Fac_Eng_OU_23_2_9.pdf
Author Kuroda Tsutomu| Osaki, Hirokazu| Matsuda, Masaaki| Fujisawa Keita|
Abstract Multi-item flexible manufacturing systems have been spread to correspond the short life-cycle and the diversification of products. Part handling plays an important role to operate multi-functional robot efficiently in these systems, and many jigs are widely used to hold a part. They should be exchanged at once according to changing products. In this paper, we propose a pin jig which holds a part with two pins, and design method of the position, length and diameter of those pins for a cylindrical part. This jig has the following characteristics. As a surface of the jig is inclined to use gravity, the part can be fixed without any external forces. Therefore the structure of jig becomes simple, and loading and unloading of a part becomes easy for a robot hand.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-03-30
Volume volume23
Issue issue2
Start Page 9
End Page 19
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307693
JaLCDOI 10.18926/15471
FullText URL Mem_Fac_Eng_OU_24_1_25.pdf
Author Kajihara, Yasuhiro| Osaki, Hirokazu|
Abstract An expert system, in which preconditions and rules are expressed in logical formulas, is developed to support the scheduling of an automated job shop type multi-item assembly line. This system has the foIIowing characteristics to apply any case of schedulings: (1)Forward scheduling orbackward scheduling can be made. (2)The criterion on the input order of products, the dispatching process at each assembly station, and the selection of products from a buffer can be selected from several priority criteria. (3)Layout, number and velocity of vehicles, and the capacity of each buffer can be changed.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 25
End Page 39
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307454
JaLCDOI 10.18926/15470
FullText URL Mem_Fac_Eng_OU_24_1_13.pdf
Author Uno, Yoshiyuki| Nakajima, Toshikatsu| Endo, Osamu|
Abstract The generation mechanism of crater in electrical discharge machining is analyzed with a single pulse discharge device for alloy tool steel, black alumina ceramics, cermet and cemented carbide, investigating the gap voltage, the discharge current, the shape of crater, the wear of electrode and so on. The experimental analysis makes it clear that the shape of crater has a characteristic feature for the kind of workpiece. The shape of electrode, which changes with the wear by an electric spark, has a significant effect on the shape of crater. The diameter and the depth of crater have a close relation to the discharge energy for alloy tool steel, black alumina ceramics and cermet, while those for cemented carbide are related to the discharge current. The shape factor which is the ratio of the depth to the diameter of crater is different for the work material.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 13
End Page 24
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307269
JaLCDOI 10.18926/15469
FullText URL Mem_Fac_Eng_OU_23_2_1.pdf
Author Kamiyabu, Hideto| Sakakibara, Akira| Maeda, Hironobu| Hida, Moritaka|
Abstract Surface tension (γ(L)) and contact angle (θ) of gallium related to wettability on Teflon and other substrates (Al(2)O(3), SiO(2), glass, graphite, BN, AI, Ni, As etc.) were investigated. The values of Teflon were 0.70(6)N/m and 158° in pure argon atmosphere, and the ones of other substrates were listed in a table in this text. We were interested especially in the relative values, γ(L)'s, on the substrates as compared with γ(L) on Teflon substrate. Liquid Ga showed spreading wetting on pure Ni metal and adhesional wetting on Al (supposed to be covered by A1(2)O(3)) and on metallic polycrystal As. Surface tension of Ga was remarkably decreased by a kind of oxide contamination due to oxygen in air. The surface layer coated by the contamination was of amorphous state nearly same as liquid Ga. The amorphous coat caused liquid Ga rather high supercooling of △T~35K. It seems that the contamination layer (oxide fi1m) smeared the crystal nucleation sites on the free surface of liquid Ga
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-03-30
Volume volume23
Issue issue2
Start Page 1
End Page 8
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307294
JaLCDOI 10.18926/15468
FullText URL Mem_Fac_Eng_OU_23_1_69.pdf
Author Totsuji, Hiroo| Takei Makoto|
Abstract The statistical properties of two-dimensional systems of charges in semiconductor superlattices are analyzed and the dispersion relation of the plasma oscillation is calculated. The possibility to excite these oscillations by applying the electric field parallel to the structure is discussed.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-11-22
Volume volume23
Issue issue1
Start Page 69
End Page 82
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307988
JaLCDOI 10.18926/15467
FullText URL Mem_Fac_Eng_OU_23_1_61.pdf
Author Yamamoto, Yoshitake| Yamamoto, Tatsuma|
Abstract Skin impedance satisfies the Cole-Cole arc's law. The change of skin impedance during GSR (Galvanic Skin Reflex) can be expressed by the change of equivalent parallel resistance approximately. Using these characteristics, the complicated change of skin impedance during GSR can be determined continuously from the measurement value in one frequency point.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-11-22
Volume volume23
Issue issue1
Start Page 61
End Page 68
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307322
JaLCDOI 10.18926/15461
FullText URL Mem_Fac_Eng_OU_28_2_53.pdf
Author Totsuji, Chieko| Matsubara Takeo| Miyata Satoru|
Abstract One of the best known solid solution of perovskites is the PbTiO(3)-PbZrO(3) system which is usually abbreviated as PZT. In the phase diagram of this system, there is a drastic phase change from tetragonal to rhombohedral at the molar ratio around 50:50. The PZT crystals are widely used as a practical piezoelectric material because of its very strong piezoelectric effect near this morphotropic phase boundary. We try to explain this anomaly in piezoelectric constant by a phenomenological theory.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1994-03-15
Volume volume28
Issue issue2
Start Page 53
End Page 58
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307223
JaLCDOI 10.18926/15458
FullText URL Mem_Fac_Eng_OU_28_2_33.pdf
Author Wang, Ming| Ahmed, Anis| Wada, Osami| Koga, Ryuji|
Abstract Proposed here is a convenient optical system to collimate the crescent shaped blue laser beam radiated from a Cerenkov SHG in channel waveguide configuration. This collimation system is consisted of a parabolic mirror and has a very large tolerance to the mirror displacement. The anisotropy of the nonlinear crystal on which the waveguide is fabricated has been taken into account. The optimum mirror location is given to obtain a collimated blue laser beam with an aberration less than 0.07λ. By using an objective lens, the collimated beam can be focused down to a thin beam with the spot size less than 1μm.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1994-03-15
Volume volume28
Issue issue2
Start Page 33
End Page 44
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307149
JaLCDOI 10.18926/15456
FullText URL Mem_Fac_Eng_OU_28_2_21.pdf
Author Yamamoto, Kyoji| Jiao Xuezhen|
Abstract An experimental investigation has been made of the cyclone dust collector with a perforated internal rotating cylinder. The size of the rotating cylinder is of 0.5D, where D is the diameter of the cyclone body, and is the same size as the outlet tube. The dust collection efficiency as well as the pressure loss has been measured when the inlet flow speed is 9 ~ 21 m/s and the rotating speed of the cylinder is 37 ~ 63 m/s. The velocity and pressure distributions were also measured. It is found that the collection efficiency decreases and the pressure loss increases as the rotating speed increases. It is also shown that both the inward radial velocity and the upward vertical velocity become large as the rotating cylinder increases its speed. As a whole, the rotation of the internal cylinder makes worse performance of the cyclone dust collector.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1994-03-15
Volume volume28
Issue issue2
Start Page 21
End Page 31
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307575