JaLCDOI 10.18926/15401
FullText URL Mem_Fac_Eng_OU_30_2_21.pdf
Author Tachibana Hiroyuki| Totsuji, Hiroo|
Abstract In order to apply quantum waveguides to electronic devices, we calculate the electrostatic potential in the split-gate quantum wire and establish the relation between the electrostatic potential and the square well potential which is usually assumed in simulations of these waveguides. The height and width of the square well potential are expressed as simple functions of the gate voltage and their dependencies are clarified. The results may be useful in calculating the characteristics of electronic devices based on quantum waveguides as functions of controllable parameters such as gate voltage.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1996-03-29
Volume volume30
Issue issue2
Start Page 21
End Page 25
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307620
JaLCDOI 10.18926/15397
FullText URL Mem_Fac_Eng_OU_30_2_1.pdf
Author Takemoto, Yoshito| Hida, Moritaka| Sakakibara, Akira|
Abstract The mechanism of brittle fracture in Ti-14mass % Mo alloy aged for 1x10(6)s at 623K was studied using transmission electron microscopy (TEM) and dynamic hardness test (DHT) on the structure deformed by means of tensile elongation at elevated temperature or cold rolling. Many band products were observed by TEM in either deformed specimens. These band products were identified to neither slips nor twinning bands, moreover, they were different from α , α ' and α " phases. The band product consisted of β phase and granular unknown phase which was transformed by deformation from ω phase. The newly discovered phase, named β" phase, in the band products had a body-centered triclinic structure. The β" was similar to the ω zone with respect to the morphology and the concentration of Mo, but it resembled β in structure. The result of DHT on the band products and the matrix showed that the band products were softer than the matrix. It is suggested that the band products are easily deformed because of the disappearance of obstacles such as ω phase, and consequently behave like paths to lead cracks preferentially.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1996-03-29
Volume volume30
Issue issue2
Start Page 1
End Page 7
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307225
JaLCDOI 10.18926/19619
FullText URL Mem_Fac_Eng_OU_31_1_1.pdf
Author Sakakibara, Akira| Nakagawa, Keiyu| Hosokawa, Norio| Kanadani, Teruto|
Abstract Dependence of precipitation hardening on the distance from specimen surface and effect of the surface layer on the fatigue strength of an Al-1.2mass% Si alloy were studied by microhardness test, transmission electron microscopy and repeated tension fatigue test. Rate of age-hardening was slower in the vicinity of surface than in the interior of the specimen aged at 423K after quenching from 853K. The result of the electron microscopy was that the size ot Si precipitates formed in the vicinity of surface was smaller than in the interior of specimen aged for 6ks at 423K. This difference was considered to be caused by the effect of the surface as vacancy sinks which slowed down the growh of Si precipitates in the vicinity of the specimen surface. A specimen surface layer whose hardness was different from that of the specimen interior was formed at the vicinity of the surface when the specimen was aged at relatively low temperature such as 423K. The fatigue strength in repeated tensile test ot the specimen did not depend on whether the specimen surface layer was present or not.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1996-12-27
Volume volume31
Issue issue1
Start Page 1
End Page 3
ISSN 0475-0071
language 英語
File Version publisher
NAID 120005816788
JaLCDOI 10.18926/19622
FullText URL Mem_Fac_Eng_OU_31_1_5.pdf
Author Shimamura, Kaoru| Zhang Chunxiao| Uchida, Tetsuya|
Abstract Rigid polymer poly(p-phenylene benzobisthiazole) was crystallized from dilute solution. Electron microscopy showed that upon quenching, flat fibrils with several nm thick were produced. Subsequent heat treatment in solvent changed the fibril into "shish-kebab". On the other hand, by isothermal crystallization, an aggregate of parallel rod-like crystals was obtained. The molecular chains were accommodated normal to the rod. Based on the observation of crystal morphology, the isothermal crystallization mechanism was proposed. Because of regidity of polymer chains and wide distribution of the molecular length, the chain ends were inevitably included within the crystals resulting in crystal defects such as axial shift, lattice curvature and edge dislocation which were directly observed by lattice imaging.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1996-12-27
Volume volume31
Issue issue1
Start Page 5
End Page 10
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309167
JaLCDOI 10.18926/15166
FullText URL Mem_Fac_Eng_OU_31_1_19.pdf
Author Totsuji, Hiroo| Kishimoto, Tokunari| Totsuji, Chieko|
Abstract As a model of dusty plasmas in external fields, Yuka.wa system in a one-dimensional external field is analyzed by molecular dynamics simulations and theoretical approaches. It is shown that particles form clear thin layers (sheets) at low temperatures and the number of layers changes discretely with characteristic parameters of the system, accompanying the rearrangements of whole system from nearly equipartitioned layers to also nearly equipartitioned layers. The number, positions and populations of layers are obtained as functions of characteristic parameters. The shell (sheet) model which has been successful for confined one-component plasmas is extended to this system and results of numerical experiments are reproduced to a good accuracy. The effect of cohesive energy in each layer is of essential importance to reproduce discrete changes in the number of sheets.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1996-12-27
Volume volume31
Issue issue1
Start Page 19
End Page 33
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307616
JaLCDOI 10.18926/19624
FullText URL Mem_Fac_Eng_OU_31_1_11.pdf
Author Zhang Chunxiao| Tanigawa Satoshi| Uchida, Tetsuya| Shimamura, Kaoru|
Abstract Poly[(benzo[1,2-d:5,4-d']bissthiazole-2,6-diyl)-1,4-phenylene](cis-PBZT)with a relatively high molecular weight was prepared by a new synthesis route. Properties of the synthesized polymer, such as thermostability, liquid crystallinity etc. were investigated and compared with those of trans-PBZT. cis-PBZT was crystallized from dilute solution and the electron microscopy showed that the precipitate was a rod-like crystal similar to that of trans form. In spite of rigid nature of the back bone, cis-PBZT showed poor crystallinity.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1996-12-27
Volume volume31
Issue issue1
Start Page 11
End Page 17
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309203
JaLCDOI 10.18926/19596
FullText URL Mem_Fac_Eng_OU_31_2_45.pdf
Author Osaka, Akiyoshi| Kobayashi Keizo| Hayakawa, Satoshi| Ohtsuki, Chikara|
Abstract The thermal expansion coefficient of some bioactive glasses in the system CaO-SiO(2)-B(2)O(3) were adjusted to be similar to that of titanium by controlling the composition. A glass of composition 45CaO・30SiO(2)・25B(2)O(3) was selected among those as the enameling glass. A slurry was prepared by mixing the glass powder and ethanal to be developed on titanium and heated at 740℃ for 30 min. Thus treated specimen was soaked in a simulated body fluid (Kokubo solutiion). FT-IR reflection and thin film X-ray diffraction analyses indicated apatite formation on the glass coating layer within 12 h of soaking in the fluid. Thus titanium could be provided with bioactivity due to the enameling.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1997-03-28
Volume volume31
Issue issue2
Start Page 45
End Page 51
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309181
JaLCDOI 10.18926/19594
FullText URL Mem_Fac_Eng_OU_31_2_39.pdf
Author Imayoshi Naoki| Hayakawa, Satoshi| Ohtsuki, Chikara| Osaka, Akiyoshi|
Abstract Nb(2)O(5)-and Ta(2)O(5)-doped calcium si1icate glasses were soaked for various periods in a simulated body fluid(Kokubo solution) up to 30 days. Apatite formation ability of the surface of these glasses were investigated with thin-film X-ray diffraction and FT-IR reflection spectroscopy. The effects of these additive oxides on the bioactivity of CaO・SiO(2) based glass were discussed. A small amount of Nb(2)O(5) and Ta(2)O(5) suppressed the rate of silica hydrogel layer formation and the apatite formation on the surface of the glasses. The rate of the apatite nucleation on the surface of Nb(2)O(5)-doped calcium silicate glass was slower than that on the surface of Ta(2)O(5)-doped calcium silicate glass. It was concluded that the decrease in the apatite forming ability of calcium silicate glasses by these additive oxides is attributed to the suppression of formation of silica hydrogel layer which plays an important role in apatite nucleation.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1997-03-28
Volume volume31
Issue issue2
Start Page 39
End Page 44
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309151
JaLCDOI 10.18926/19599
FullText URL Mem_Fac_Eng_OU_31_2_53.pdf
Author Fujihara Yutaka| Osaki, Hirokazu|
Abstract This paper presents a method using simulated annealing(SA) and genetic algorithm(GA) to solve the plant layout problem in which the layout is evaluated by material handling cost and maintainability. In the former study about facility layout problem, it was either the minimization of the objeective function consisting of transport cost or the maximization of the objective function consisting of closeness rating. In this paper, both transport cost and maintainability were included in the objective function to be minimized. The plant layout problem, this paper proposes the heuristic procedures to obtain a suboptimal layout solution by combining SA with GA. From the simulation by computer, it concluded that the method which SA is combined with GA is more efficient than the method which utilizes SA and GA independently.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1997-03-28
Volume volume31
Issue issue2
Start Page 53
End Page 60
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309131
JaLCDOI 10.18926/19589
FullText URL Mem_Fac_Eng_OU_31_2_11.pdf
Author Ishii Kouta| Takemoto, Yoshito| Hida, Moritaka|
Abstract Fine particles of Ti-V alloy were prepared by means of arc method and were investigated on internal structure and phase transformation using HR-TEM and EDS. Martensite phase was observed in a particle containing comparatively low concentration of V, and ω phase was also found to exist in a nearly 15% V particle. The structure of the ω phase in the fine particle is remarkably expanded in comparison with the bulk sample, and the ω phase is unstable, so that it has disappeared in a few seconds during TEM observation.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1997-03-28
Volume volume31
Issue issue2
Start Page 11
End Page 20
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309004
JaLCDOI 10.18926/19588
FullText URL Mem_Fac_Eng_OU_31_2_1.pdf
Author Arisawa Hideaki| Song Zhi-Yi| Takemoto, Yoshito| Hida, Moritaka|
Abstract The microstructure of oxidizing magnesium at elevated temperatures has been studied using HR-TEM, SEM and EDS. Two kinds of thin magnesium specimen for TEM observation were prepared. One was oxidized after preparing TEM foil of magnesium, the other was prepared from an oxidized bulk magnesium for observing the cross-section of oxide/Mg interfacial region. In the former, several oxides(MgO) morphologies were observed depending on the temperature and time of the oxidization. The growth of needle-like oxides formed at 573K and mottled oxides formed at 773K were recognized as a remarkable phenomenon belonging to the local oxidization. These oxides were composed of poly-crystal. The thin uniform oxidization layer was also observed in all conditions. In the cross-sectional observation, the local oxide layer, nearly 300nm in thickness, on the matrix(Mg) were observed. The thin uniform oxidized layer of bulk samples was identified as a kind of modified layer (~40nm in thickness) in which the formation of HR-TEM lattice fringes were prevented by the strain due to the slight oxidization.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1997-03-28
Volume volume31
Issue issue2
Start Page 1
End Page 10
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309082
JaLCDOI 10.18926/19591
FullText URL Mem_Fac_Eng_OU_31_2_21.pdf
Author Oka, Hisao| Nakamura, Takahiko|
Abstract In evaluating the stiffness of skin surface, internal structures such as bone and muscle often affect the measurements. In the present paper, acoustic random vibration is used to estimated the viscoelasticity of a silicone-gel model. This viscoelasticity, which includes two different stiffness strata, is first estimated using a mechanical impedance spectrum, which describes the relation between the depth and viscoelasticity of internal objects. This method is applied to the depth of a silicone-gel tumor model measured by ultrasound imaging and the viscoelasticity of internal gel can be accurately estimated.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1997-03-28
Volume volume31
Issue issue2
Start Page 21
End Page 27
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309105
JaLCDOI 10.18926/19601
FullText URL Mem_Fac_Eng_OU_31_2_61.pdf
Author Yamada Mitsuru| Osaki, Hirokazu|
Abstract At present, the two dimensional CAD systems which are used to make drawings go around widely. But in order to use design data at the lower stream of production process, the replacement from the two dimensional CAD systems to the three dimensional CAD systems have started. Accordingly it is dimensional drawings for the three dimensional shapes. And it is also necessary to store them in the three dimensional CAD systems. And in the studying of the machine vision which is often used as "Eyes of robot" , it is being studied the method to recognize the three dimensional objects from the two dimensional image. This is the problem about data exchange, too. Therefore in this report, we propose the method to exchange the plural two dimensional elements of figure from image relations between elements were found from reference of the element coordinates. Next, the three dimensional shapes were reasoned from reference of the knowledge (for corner, etc) prepared beforehand. Then that data were exchanged to the three dimensional CAD data. We report one example about this method.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1997-03-28
Volume volume31
Issue issue2
Start Page 61
End Page 65
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309050
JaLCDOI 10.18926/19592
FullText URL Mem_Fac_Eng_OU_31_2_29.pdf
Author Oka, Hisao| Ohshima, Masakazu|
Abstract Knee replacement arthroplasty is indicated for the patient with advanced knee pain, knee deformation, and knee functional disorder. The aim of this study was to estimate loosening after a knee replacement arthroplasty. Loosening is measured by a frequency response function, and mobility by random vibration. The modal parameters for the knee joint are obtained by applying a modal analysis to the frequency response function. The values decrease as the knee joint prosthesis loosened. These parameters serve as an index for the condition between a thighbone and the prosthesis. The various indexes will greatly clarify the stage of advance in the loosening of knee-joint prostheses.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1997-03-28
Volume volume31
Issue issue2
Start Page 29
End Page 37
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309172
JaLCDOI 10.18926/19603
FullText URL Mem_Fac_Eng_OU_31_2_67.pdf
Author Li Zhenzi| Osaki, Hirokazu| Kajihara, Yasuhiro|
Abstract In this paper, we propose the price determination method using the parameter of the price elasticity that shows the relation between price and demand. Firstly, the state of the price elasticity is examined under the condition that the relation between price and demand are assumed by the inverse proportional function, the linear function and the quadratic function. Secondly, the profit is estimated for each product by break even point analysis. And the price is determined under the condition that the relation between the demand and price is shown by one of three demand-pridce functions above mentioned.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1997-03-28
Volume volume31
Issue issue2
Start Page 67
End Page 72
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309056
JaLCDOI 10.18926/19632
FullText URL Mem_Fac_Eng_OU_32_7.pdf
Author Adli| Yamamoto, Yoshitake|
Abstract This paper describes a new measurment method and principle of power line interference elimination in ECG signal using inverse loop and AC power line configuration (APC). First, we considered that magnetic induction effect not only depend on a conductive loop area that formed by shielded wires that connect the object and amplifier but also effect of body area effective must be considered. It is simple and useful because interference can be eliminated to very small value show that the condition and it can be applied in a real ECG signal recording. Second, results show that the contribution of displacement currents into the object especially APC in vertical configuration is smaller than it in other one. Because this method is so easy that it is convenient to be used to understand some aspects of power line interference elimination phenomenon. Hence we expect that this method can be used as one of improvement method in measurement system of ECG signal recording.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1998-04-20
Volume volume32
Issue issue1-2
Start Page 7
End Page 14
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309065
JaLCDOI 10.18926/19628
FullText URL Mem_Fac_Eng_OU_32_1.pdf
Author Guo, Changning| Uno, Yoshiyuki| Okada, Akira| Takagi, Takashi|
Abstract Low electrode wear EDM is attained by the adhesion of heat resolved carbon made from kerosine type machining fluid to the electrode end surface. This phenomenon, however, occurs only under long pulse duration. Therefore, the low electrode wear EDM under finishing condition is impossible so far. In the previous paper, the authors developed a turbostratic carbon electrode whose structure is very similar to the heat resolved carbon generated in EDM process and made it clear that the low electrode wear EDM was possible by using the electrode even under finishing condition. In this study, a carbon coated electrode and a SiC coated one which can be made rapidly at low cost were developed and their EDM characteristics were investigated. Experimental analysis pointed it out that both electrodes were effective in reducing electrode wear under finishing condition.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1998-04-20
Volume volume32
Issue issue1-2
Start Page 1
End Page 6
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309140
JaLCDOI 10.18926/19636
FullText URL Mem_Fac_Eng_OU_32_23.pdf
Author Totsuji, Hiroo| Kishimoto, Tokunari| Totsuji, Chieko|
Abstract Parameters characterizing the structure ot confined Yukawa system are estimated for 'dusty plasmas', clouds of charged macroscopic particles formed near the boundary between plasma and the sheath and leviated by negatively biased electrode. When we have dust particles with different ratios of charge to mass, they form a two-dimensional Yukawa mixture or separate two-dimensional one-companent Yukawa systems, depending on the charge density in the sheath and number density of dust particles. In order to provide a basis for numerical simulations on Yukawa mixtures including Coulombic case, we summarize mathematical expressions necessary for molecular dynamics.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1998-04-20
Volume volume32
Issue issue1-2
Start Page 23
End Page 41
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309150
JaLCDOI 10.18926/19637
FullText URL Mem_Fac_Eng_OU_32_43.pdf
Author Totsuji, Chieko| Matsubara Takeo|
Abstract Large isotope effects have been observed in various kinds of hydrogen bonded ferro / antiferroelectrics. In clariflying their origin, themodynamic properties of the hydrogen bond are of essential importance. Two numerical methods are applied to analyze the model for isolated hydrogen bond at finite temperatures and the results of excited energy levels of proton or deuteron are examined. It is found that the second excited state is not far enough from the first excited state to be neglected discussing themodynamic properties of hydrogen especially in their ordered states.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1998-04-20
Volume volume32
Issue issue1-2
Start Page 43
End Page 54
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309098
JaLCDOI 10.18926/19634
FullText URL Mem_Fac_Eng_OU_32_15.pdf
Author Mori, Masahiro| Oka, Hisao|
Abstract In a stiffness estimation of living body, an internal structure under the skin influences the measured results. Because a different stiffness of body caused by bones and muscles is obtained. In this paper, by using a measurement system of mechanical impedance, the relations between a viscoelasticity and a distance from the surface of silicone-gel model is calculated. This relation is applied to silicone-gel tumor model and a shape and a viscoelasticity of semi-sphere silicone-gel tumous are estimated. The obtained results are expressed as a reconstructed 3-D image of shape / viscoelasticity. The revised curve-fitting of mechanical impedance and the cancellation of peripheral vibration influence are proposed in order to increase an estimation acccuracy.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1998-04-20
Volume volume32
Issue issue1-2
Start Page 15
End Page 22
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309047