result 21004 件
| 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 | English |
| 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 | English |
| 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 | English |
| 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 | English |
| File Version | publisher |
| NAID | 120002307322 |
| JaLCDOI | 10.18926/15466 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_24_1_1.pdf |
| Author | Yoshida, Akira| Ohue, Yuji| Fujii, Masahiro| |
| Abstract | To clarify the effects of a drive system lubricant additive upon rolling fatigue of rollers manufactured from carburized and hardened steel, three types of oil were used as lubricants: one mineral base oil and the other two mineral base oils to which an S-P additive package and ATF additive package were added, respectively. These specimens were tested for sliding/rolling fatigue and examined for failure on the surface, rolling fatigue strength, and other properties. Roller surface temperatures and inter-roller frictional coefficients were found scarcely affected by the type of oil used. Irrespective of the difference in oil type, failure on the surface was found to be entirely spalling attributable to cracks generated in the subsurface. The depth at which spalling cracks had taken place was found nearly coincident with the depth at which a ratio of reversing orthogonal shear stress to hardness had amplitude A(Tyz/Hv) maximized. These depths were larger as Hertz stress became more prominent. Nevertheless, they were found hardly affected by the type of oil. Although rolling fatigue strength did not show a significant difference dependent upon the type of oil, it may be said that fatigue life would be somewhat negatively affected by an extreme pressure coated film with a content of sulfur and phosphorus. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1989-11-29 |
| Volume | volume24 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 12 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307588 |
| JaLCDOI | 10.18926/15465 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_23_1_49.pdf |
| Author | Oka, Hisao| Yamamoto, Tatsuma| Isayama Yoshiharu| |
| Abstract | In the field of dental study it is most fundamental and necessary to estimate the condition of periodontium. In order to examine a mechanical characteristics of periodontium, the theoretical displacement response to periodontal mechanical model (three elements model) are strictly solved in case of some pulse excitations. Impact excitations (rectangular, triangular and half-cycle sine pulse) are given in physical and mathematical definitions and complete solutions to the impact excitations are provided. The triangular pulse excitation which is obtained by means of a fracture of pencil-lead is most suitable. The mechanical parameters of periodontium are given using this input excitation. This is experimentally confirmed by artificial tooth model. The obtained mechanical characteristic of the periodontal tissues can be applied to clinical diagnosis. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1988-11-22 |
| Volume | volume23 |
| Issue | issue1 |
| Start Page | 49 |
| End Page | 60 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307622 |
| JaLCDOI | 10.18926/15464 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_28_2_77.pdf |
| Author | Osaka, Akiyoshi| Kawamura Haruyuki| Miura, Yoshinari| |
| Abstract | Amorphous films of lead oxyfluorosilicate were prepared with a rf-sputtering technique, and the distribution profiles of the component elements and chemical states of the fluoride ions were analyzed with an X-ray photoelectron spectrometer. Si atoms with an expanded coordination, O(4)Si-F, were present near the surface, and O(3)Si-F units were present in the deeper part of the films. Electrical resistance indicated transition to a conduction state for the films containing fluoride ions, while the films were crystallized to precipitate low quartz by the irradiation of He-Ne laser of 3 mW up to 1 sec. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1994-03-15 |
| Volume | volume28 |
| Issue | issue2 |
| Start Page | 77 |
| End Page | 84 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307766 |
| JaLCDOI | 10.18926/15462 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_23_1_39.pdf |
| Author | Osaka, Akiyoshi| Yuasa Motokazu| Miura, Yoshinari| Takahashi, Katsuaki| |
| Abstract | Sodium borosilicate gels of compositions similar to that of Vycor(R) glass like 80SiO(2).15B(2)O(3).5Na(2)O (wt%) were prepared from hydrolysis and polycondensation of metal alkoxides under the HCl catalysis. Variation of specific surface area and porosity with temperature indicated that closed pores were opened below 400℃, and collapsed above 450℃ after the porosity reached a maximum value around 450℃. The structural evolution was examined due to IR spectra and a phase separation in the gels was observed. The solubility of the gels into 1N-HCl was studied as a function of the treatment temperature. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1988-11-22 |
| Volume | volume23 |
| Issue | issue1 |
| Start Page | 39 |
| End Page | 48 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307518 |
| JaLCDOI | 10.18926/15459 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_23_1_31.pdf |
| Author | Miura, Yoshinari| Yuasa Motokazu| Osaka, Akiyoshi| Takahashi, Katsuaki| |
| Abstract | Sodium borosilicate gels of compositions similar to that of Vycor(R) glass like 80SiO(2).15B(2)O(3).5Na(2)O(wt%) were prepared from hydrolysis and polycondensation of tetraethyl orthosilicate, trimethyl borate, and sodium methylate under the HCl catalysis. Variation of the gelation time is examined as a function of the mixing ratio of the starting materials and the catalyst. The thermal behavior of the gels has been discussed on the basis of their TG and DTA traces. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1988-11-22 |
| Volume | volume23 |
| Issue | issue1 |
| Start Page | 31 |
| End Page | 38 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307464 |
| JaLCDOI | 10.18926/15455 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_23_1_1.pdf |
| Author | Matsuda, Masaaki| Osaki, Hirokazu| |
| Abstract | Display equipment has been used as communication media in the factory, office, and home. In order to communicate effectively, it is necessary to clarify the characteristics of eye movement in the case of looking at the display. The development of Eye Camera enables us to measure eye movement during work, so that we can collect the many data of eye movement during work. In this study, we proposed a method to evaluate the visual work using the distribution of visual points in X and Y axis. The cumulative distribution is approximated by the logistic curve which shows the symmetry and kurtosis by the parameter. The proposed method was applied to the three typical display models, that is, the digital meter model, reading model, and game model. In the digital meter model, the visual points were distributed symmetrically along the meters, and the symmetry and kurtosis of the distribution varied by the arranged direction of the meter. In the reading model, the visual points were distributed nearly symmetrically and uniformly in each axis and they were moved around the character and line from the period of spectrum analysis. In the game model, the visual points moved according to the target and were distributed symmetrically in the Y axis. And whether the target moved vertically or horizontally, the kurtosis of the distribution became equal in each axis. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1988-11-22 |
| Volume | volume23 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 12 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307354 |
| JaLCDOI | 10.18926/15448 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_28_2_1.pdf |
| Author | Takemoto, Yoshito| Sakakibara, Akira| Hida, Moritaka| |
| Abstract | Fine particles of Ti-Mo alloy have been prepared by means of arc method, and investigated on internal structure and phase transformation using HR-TEM and EDS. Martensite phase was observed in a particle containing comparatively low concentration of Mo, and ω phase was also found to exist in a nearly 14 % M0 particle. The structure of the ω phase in the fine particle is expanded and remarkably unstable in comparison with the bulk sample, so that it has disappeared in a few seconds during TEM observation. Moreover, the β structure of Ti-Mo particles has changed to the unusual fcc phase with irradiation of a strong electron beam. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1994-03-15 |
| Volume | volume28 |
| Issue | issue2 |
| Start Page | 1 |
| End Page | 7 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307644 |
| JaLCDOI | 10.18926/15447 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_28_1_129.pdf |
| Author | Taniguchi, Takeo| Hirose, Sohichi| Ouchterlony Finn| Nakagawa Kohji| Miyaji Akihiko| Fukuoka Yasufumi| |
| Abstract | The testing method of rock toughness is proposed by the international society of rock mechanics (ISRM), but the results may be influenced by the test pieces, and the details of the crack propagation and the stress intensity factors are not clarified through the testing. Also the experimental test requires tedious works for the preparation of test specimen and economical responsibility. The present study aims to simulate numerically the rock toughness testing which is proposed by ISRM. For this purpose, the authors propose a numerical method which can simulate the experimental testing, and they show the propriety of the proposed method by comparing the results with the experimental and other numerical methods. At the same time, they clarify the details of crack propagation behaviors in rocks, and show the change of the stress intensity factors. The proposed method is based on the displacement-type finite element method, and several techniques are introduced to obtain accurate solution of the mechanical behavior near the crack-tip area. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1993-11-30 |
| Volume | volume28 |
| Issue | issue1 |
| Start Page | 129 |
| End Page | 138 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307126 |
| JaLCDOI | 10.18926/15446 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_22_1.pdf |
| Author | Oka, Hisao| Yamamoto, Tatsuma| |
| Abstract | Biomechanical impedance is relatively small compared to industrial mechanical impedance. Thus it is difficult to measure it precisely. A biomechanical impedance measuring system was developed for portable use by means of random excitation. This system doesn't require a fixed body and vibrator supporting apparatus. In order to obtain an impedance spectrum, the FFT processing is performed using a personal computer. The spectra of the biomechanical impedance which is measured on body surfaces depend on body positions and can be roughly classified into three spectra patterns : soft, stiff and intermediate. During the measurement, the measuring conditions (preload, diameter of the vibrating tip etc.) influence the results. However, it became clear that the linearity of the biomechanical impedance was satisfied in the limited measuring conditions. Accordingly it is possible to standardize the impedance and to compare it with the results under different measuring conditions. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1988-03-31 |
| Volume | volume22 |
| Start Page | 1 |
| End Page | 14 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307480 |
| JaLCDOI | 10.18926/15442 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_28_1_87.pdf |
| Author | Motojima Isao| Kono, Iichiro| Nishigaki, Makoto| |
| Abstract | In recent years, construction or planning of large-scale underground structures, such as underground power plants, underground oil storage plants and nuclear power plants have been coming into consideration in Japan. To construct such as large-scale underground structures, one of the most important problems is to make clear beforehand the behavior of groundwater around these structures and the other is to carry out proper countermeasure of groundwater, so that these structures can be constructed safely and maintained stability over a long time period. This report describes the results of theoretical studies on the drain systems and at the same time, discusses the drain systems around the underground cavern for the practical underground power stations. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1993-11-30 |
| Volume | volume28 |
| Issue | issue1 |
| Start Page | 87 |
| End Page | 128 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307220 |
| JaLCDOI | 10.18926/15440 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_28_1_71.pdf |
| Author | Nishigaki, Makoto| Sudinda Teddy| Hishiya Tomoyuki| Kohno, Iichiro| |
| Abstract | In this paper, method of Eulerian Lagrangian numerical analysis is used to described Advection-Dispersion phenomena. The influence of concentration to the density of fluid is considered. A laboratory model of a two dimensional confined aquifer containing an isotropic, homogeneous porous medium (Hosokawa et.al 1989) was used to validate the applicability of Advection-Dispersion of numerical analysis with steady and unsteady state condition [1]. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1993-11-30 |
| Volume | volume28 |
| Issue | issue1 |
| Start Page | 71 |
| End Page | 85 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307975 |
| JaLCDOI | 10.18926/15438 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_28_1_61.pdf |
| Author | Takeshita, Yuji| Kohno, Iichiro| |
| Abstract | Knowledge of the unsaturated soil hydraulic properties is essential requirement for prediction of seepage flow and contaminant transport through the vadose zone. Unfortunately, these parameters are usually time consuming and expensive to measure in the field and laboratory. At the present condition, there are few data accumulation for Japanese soils. In this paper, van Genuchten's closed-form expressions are described to estimate unsaturated soil hydraulic properties. To evaluate the adequacy of these expressions, comparisons are performed between observed and calculated unsaturated hydraulic properties for typical Japanese soils. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1993-11-30 |
| Volume | volume28 |
| Issue | issue1 |
| Start Page | 61 |
| End Page | 69 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307801 |
| JaLCDOI | 10.18926/15437 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_28_1_51.pdf |
| Author | Kohno, Iichiro| Tanabe Kazuyasu| Tomita Takemitsu| |
| Abstract | A technique for determining the layer structure and content of clay minerals was developed based on the relationship between temperature, and moisture characteristics of clay minerals. Moisture content in standard specimens, prepared by mixing montmorillonite, kaolinite and quartz in various proportions, was determined by measuring weight loss after heating. Based on the results from differential thermal analysis tests, the ignition loss method was found to be widely applicable to clays with montmorillonite and kaolinite as the main components. Dehydration of constituent water occurred at 530℃ and 800℃ in two- and three-layered clay minerals, respectively. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1993-11-30 |
| Volume | volume28 |
| Issue | issue1 |
| Start Page | 51 |
| End Page | 59 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307254 |
| JaLCDOI | 10.18926/15435 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_28_1_39.pdf |
| Author | Totsuji, Chieko| Matsubara Takeo| |
| Abstract | There are some substances in which their hydrogen bonds are considered to play quite important roles in their ferroelectric or antiferroelectric phase transition. These ferroelectrics usually have large isotope effects in phase transition temperatures and we expect the physics of hydrogen bonds is closely related to the effects. We propose a simple model describing the isolated hydrogen bond. Based on quantum-mechanical analyses of this model, we study the difference between the behavior of a proton and a deuteron in hydrogen bonds. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1993-11-30 |
| Volume | volume28 |
| Issue | issue1 |
| Start Page | 39 |
| End Page | 50 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307179 |
| JaLCDOI | 10.18926/15434 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_28_1_27.pdf |
| Author | Totsuji, Hiroo| Tachibana Hiroyuki| Fujimura Hidenori| Nara, Shigetoshi| |
| Abstract | The ground states of interacting electrons in coupled quantum wires are analyzed on the basis of the density functional theory. The exchange-correlation potential is calculated from 'exact' results given by the Green's function Monte Carlo method in two and three dimensions. It is shown that the critical density signifying the change from symmetrical to asymmetrical ground state is weakly dependent on the details of the exchange-correlation potential. These critical values are compared with the result of the three-dimensional analysis for a single wire. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1993-11-30 |
| Volume | volume28 |
| Issue | issue1 |
| Start Page | 27 |
| End Page | 38 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307565 |
| JaLCDOI | 10.18926/15432 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_28_1_1.pdf |
| Author | Nara, Shigetoshi| Miho Shigeru| Totsuji, Hiroo| |
| Abstract | The structural stabilities of bulk Si, Ge, and GaAs are discussed based on the total energy evaluated by the summation of the band structure energy and the short-range repulsive potential between ions. The band structure energy is calculated by means of the simple tight-binding method. The tight-binding parameters are determined so as to fit to the results of a pseude potential calculation and Harrison's model is employed to include the influence of lattice deformation. The short-range-force is assumed to be of the exponential form and parameters are determined so as to reproduce an experimental value of bulk modulus. This treatment qualitatively well describes structural properties in spite of the simple computational procedure and roughly gives the known variation of the total energy for a <100> uniaxial strain. This method is able to be applied to an investigation of the structural stabilities of superlattices, for example, a strained layer superlattice consisting of hetero-semiconductors. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1993-11-30 |
| Volume | volume28 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 25 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307238 |
