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 英語
File Version publisher
NAID 120002307588
JaLCDOI 10.18926/15387
FullText URL Mem_Fac_Eng_OU_30_2_9.pdf
Author Sakakibara, Akira| Kanadani, Teruto|
Abstract Fatigue strength of Al-Cu alloy was examined by a repeated tensile mode when the specimens were aged and reversion annealed. The specimen quenched from 723K and aged fully around room temperature showed fatigue strength which depended on the existence of soft layer, while the specimen quenched from 723K and aged in the same way showed fatigue strength independent of the existence of the soft layer. Fatigue strength of the specimen, of which the soft surface layer was removed, was the same for either quenching temperature. Fatigue strength became higher when the soft surface layer was thickened with reversion annealing for 600s at 323K after aging. The soft surface layer was thought to increase fatigue strength of the aged Al-Cu alloy as well as Al-Zn alloy.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1996-03-29
Volume volume30
Issue issue2
Start Page 9
End Page 13
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307694
JaLCDOI 10.18926/15407
FullText URL Mem_Fac_Eng_OU_26_1_1.pdf
Author Sakakibara, Akira| Kanadani, Teruto|
Abstract Reversion of the age-hardened Al-15mass % Zn alloy, in which ellipsoidal GP zones were formed, was investigated by hardness test. Ellipsoidal zones were reverted more quickly near the surface and grain boundary than in the interior, as spherical zones did. The results confirm their role as sources for vacancies in reversion.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1991-11-30
Volume volume26
Issue issue1
Start Page 1
End Page 7
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308003
JaLCDOI 10.18926/15356
FullText URL Mem_Fac_Eng_OU_34_13.pdf
Author Sakakibara, Akira| Tanimoto, Tadashi| Matsushima, Takahisa| Hosokawa, Norio| Kanadani, Teruto|
Abstract Repeated tensile fatigue strength of the low temperature age-hardened Al-Zn alloys is investigated varying the specimen thickness. Fatigue strength of the age-hardened specimens decreases with the specimen thickness when the specimen is thinner than a certain thickness, whereas fatigue strength of non age-hardened specimens, i.e., pure aluminum and dilute Al-Zn alloy, does not depend the specimen thickness. The dependence of fatigue strength on the thickness of age-hardened specimen is considered to be caused by the decrease of the strength of specimen as a whole, as a result of increase in volume ratio of the soft surface layer formed after age-hardening with decreasing specimen thickness.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2000-03-27
Volume volume34
Issue issue1-2
Start Page 13
End Page 17
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307815
JaLCDOI 10.18926/19604
FullText URL Mem_Fac_Eng_OU_33_1_1.pdf
Author Sakakibara, Akira| Kanadani, Teruto|
Abstract Aging of diolute Al-Ag alloys after quenching from low temperatures were studied mainly by electrical resistometry. Maximum resistivity observed in the aging curve of specimens quenched from high temeperature disappeared when the quenching temperature was lowered to 473 or 453K. When the quenching temperature was lowered further to 423K or lower, however, maximum resistivity reappeared. At the temperature lower than or equal to 423K but higher than the GP zone solvus, the alloys were not homogeneous but had clusters of solute atoms or fluctuation of solute concentration. Inhomogeneous distribution of solute atoms may affect the aging behavior after quenching from that temperature.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1998-11-30
Volume volume33
Issue issue1
Start Page 1
End Page 4
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309092
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 10.18926/47021
FullText URL mfe_36_2_001_006.pdf
Author Sakakibara, Akira| Kanadani, Teruto| Tashiro, Tsutomu| Yoshioka, Kazumi|
Abstract The effect of heat-treatment conditions on occurrence of serration in Al-Zn alloys was investigated. Specimens were aged for various times up to 2.6Ms at 293K or 273K after quenching from various temperatures (T(Q)), 473K to 853K, and tensile-tested at room temperature. Serration occurred more easily according as T(Q) became lower and the aging time became shorter: in the case that T(Q)=473K serration was observed even after aging for 2.6Ms, while in the case that T(Q)=773K serration did not occur irrespective of aging conditions. Serration was also recognized when the specimens were furnace-cooled from 773K to room temperature. These results together with those obtained by the electrical resistometry suggest that the serration in the low'concentrated Al-Zn alloy is caused by the formation of small GP zones whose Guinier radius is less than 1nm or some sort of solute clusters.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2002-03
Volume volume36
Issue issue2
Start Page 1
End Page 6
ISSN 0475-0071
language 英語
File Version publisher
NAID 80015497758
JaLCDOI 10.18926/15428
FullText URL Mem_Fac_Eng_OU_29_2_83.pdf
Author Tsuru, Kanji| Nishiyama Chikako| Ohtsuki, Chikara| Osaka, Akiyoshi|
Abstract One of the CaO,SiO(2)-based bioactive glasses(5OCaO・ 5OSiO (2) in mol%) were soaked for various periods in a simulated body fluid(SBF) with or without containing alcohols such as methanol, ethanol, and 1-propanol. Effect of the alcohols was investigated on the apatite formation on the glass surface with thin-film X-ray diffraction, FT-IR reflection spectroscopy and scanning electron microscopy. Under the presence of alcohols up to 0.1mol/l in the SBF an apatite layer was formed on the glass, while it consisted of crystallites similar in morphology but larger in size than that found for the SBF without the alcohols. It was concluded that the alcohols little influenced the the apatite forming ability of the CaO,SiO(2)-based glasses.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1995-03-27
Volume volume29
Issue issue2
Start Page 83
End Page 88
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307301
JaLCDOI 10.18926/19961
FullText URL Mem_Fac_Eng_OU_44_69.pdf
Author Nekado, Kenta| Kato, Hidehiro| Nogami, Yasuyuki| Morikawa, Yoshitaka|
Abstract Recently, pairing–based cryptographies have attracted much attention. For fast pairing calculation, not only pairing algorithms but also arithmetic operations in extension field should be efficient. Especially for final exponentiation included in pairing calculation, squaring is more important than multiplication. This paper proposes an efficient squaring algorithm in extension field for Freeman curve.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2010-01
Volume volume44
Start Page 69
End Page 72
ISSN 1349-6115
language 英語
File Version publisher
NAID 120002309070
JaLCDOI 10.18926/46950
FullText URL mfe_38_1-2_033_037.pdf
Author Liman, M. Sanusi| Totsuji, Chieko| Tsuruta, Kenji| Totsuji, Hiroo|
Abstract The dynamic structure factor and the spectrum of the momentum-density fluctuations of 2D Yukawa liquids are analyzed in the domain of weak and intermediate coupling and screenlng parameters. The dispersion relations of the longitudinal and transverse collective excitations are obtained and compared with the random phase approximation (RPA) and harmonic approximation for triangular lattice.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2004-03
Volume volume38
Issue issue1-2
Start Page 33
End Page 37
ISSN 0475-0071
language 英語
File Version publisher
NAID 80016863329
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 英語
File Version publisher
NAID 120002307220
JaLCDOI 10.18926/14121
FullText URL Mem_Fac_Eng_OU_40_1_40.pdf
Author Takashi, Miyake| Totsuji, Chieko| Tsuruta, Kenji| Totsuji, Hiroo|
Abstract The electron system of arbitrary degeneracy can be mapped onto a classical system where electrons of the same spin are assigned an additional interaction and the effect of degeneracy is taken into account through an imaginative temperature. We apply this method to electrons in quantum dots modeled as two-dimensional electron liquid confined in a finite domain by a harmonic potential. We analyze distribution functions by molecular dynamics instead of solving integral equations which are not so useful in the case without translational invariance.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2006-01
Volume volume40
Issue issue1
Start Page 40
End Page 43
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308268
JaLCDOI 10.18926/17826
FullText URL Mem_Fac_Eng_OU_43_8.pdf
Author Umeda Ryosuke| Totsuji, Chieko| Tsuruta, Kenji| Totsuji, Hiroo|
Abstract Metamaterial which has negative permittivity and permeability is investigated via computer simulations. Effects of the nanostructure on dielectric and magnetic properties of the material are taken into account by introducing the Drude-Lorentz model in the materials dispersion. We include multi-band process in the dielectric response in order to reproduce accurately experimental values of bulk Au thin film. Size effect on the dispersion is examined by comparing the model with that of a noble metal particle. Based on the dispersion model constructed, we analyze the electromagnetic response of nanostructured metamaterials to evanescent waves at microwave and optical frequencies via finite-difference time-domain simulatioins on parallel computer. A re- focusing and an amplification of the evanescent waves propagating through a metamaterial, consisting of metal slab/vacuum stacking, is demonstrated for the frequencies of 30GHz and 744THz.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2009-01
Volume volume43
Start Page 8
End Page 15
ISSN 1349-6115
language 英語
File Version publisher
NAID 120002308833
JaLCDOI 10.18926/15378
FullText URL Mem_Fac_Eng_OU_35_191.pdf
Author Yoshida Takanobu| Munesawa, Yoshiomi| Osaki, Hirokazu| Kajihara, Yasuhiro| Ohta Kazuharu|
Abstract We developed the disassembly system that uses the impulsive load and disassembly tools to disassemble used appliances economically. The main components of this system are impulse hammer, a lift table and developed disassembly tools. Several types of disassembly tools are developed to punch out fastened portion on a part and cut off the shaft of screw or connection pin of IC-chip. A simulation model is proposed to explain and formulate how the fastening point of product is broken and cut. Three kinds of disassembly tools are designed. The actual disassembly system is developed by using proposed simulation models and disassembly tools.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2001-03-27
Volume volume35
Issue issue1-2
Start Page 191
End Page 196
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307328
JaLCDOI 10.18926/15385
FullText URL Mem_Fac_Eng_OU_27_1_1.pdf
Author Uno, Yoshiyuki| Kubota, Shin-ichiro| Nakajima, Toshikatsu| Ogata, Kojiro| Tada, Nobuhiko|
Abstract Direct patterning of copper coated ceramic circuit board is experimentally investigated with Q-switched Nd:YAG laser in order to shorten the time of the trial manufacture of electronic circuit board and to adapt the flexible design change. It is pointed out that the fast direct patterning the speed of which reaches about 100 mm/s is possible if the repetition frequency and the average power are selected properly. Furthermore cutting off and/or drilling of ceramic board are also possible under the condition that the repetition frequency is less than 3kHz. This technique makes it possible the mask1ess patterning of ceramic circuit board which has been widely used recently in place of conventional glass-epoxy or phenolic resin circuit board, and it leads to the shorter time limit of delivery as compared with the conventional end-milling method.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1992-11-25
Volume volume27
Issue issue1
Start Page 1
End Page 10
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307702
JaLCDOI 10.18926/15269
FullText URL Mem_Fac_Eng_OU_35_47.pdf
Author Doumae, Yukihiro| Konishi, Masami| Imai, Jun| Asada, Hideki| Kitamura, Akira|
Abstract In this paper, an identification method of motor parameters for the diagnosis of rotor bar defects in the squirrel cage induction motor is proposed. It is difficult to distinguish the degree of deterioration by a conventional diagnostic method such as Fourier analysis. To overcome the difficulty, a motor simulator is used to identify the degree of deterioration of rotors in the squirrel cage induction motor. Using this method, the deterioration of rotor bars in the motor can be estimated quantitatively.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2001-03-27
Volume volume35
Issue issue1-2
Start Page 47
End Page 51
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307181
JaLCDOI 10.18926/15371
FullText URL Mem_Fac_Eng_OU_35_163.pdf
Author Uchiyama Hiromitsu| Miyazaki Satoshi| Osaki, Hirokazu| Kajihara, Yasuhiro| Munesawa, Yoshiomi| Matsuki Katsunori|
Abstract We develop an assembly robot system for assembling the flexible belt-shaped subject. An image processing method is developed to recognize the belt-shaped subject. This method is able to determine the grasping point and grasping angle for piking up a subject by a multiple hands unit. CAD information is used to determine the grasping point. The multiple hands unit is developed, which is able to grasp all grasping points of a subject at a time. In addition, the image processing method is used to judge whether a subject is fastened accurately at right position or not during the assembly.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2001-03-27
Volume volume35
Issue issue1-2
Start Page 163
End Page 168
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307229
JaLCDOI 10.18926/15380
FullText URL Mem_Fac_Eng_OU_35_197.pdf
Author Nogami, Yasuyuki| Morikawa, Yoshitaka|
Abstract Modern communication engineerings, such as elliptic curve cryptographies, often requires algebra on finite extension field defined by modulus arithmetic with an irreducible polynomial. This paper provides a new method to detemine the minimal (irreducible) polynomial of a given proper element in finite extension field. In the conventional determination method, as we have to solve the simultaneous equations, the computation is very involved. In this paper, the well known "trace" is extended to higher degree traces. Using the new traces, we yield the coefficient formula of the desired minimal polynomial. The new method becomes very simple without solving the simultaneous equations, and about twice faster than the conventional method in computation speed.
Keywords finite field minimal polynomial irreducible polynomial higher degree trace trace cryptography
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2001-03-27
Volume volume35
Issue issue1-2
Start Page 197
End Page 205
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307992
JaLCDOI 10.18926/15498
FullText URL Mem_Fac_Eng_OU_25_1_99.pdf
Author Nishigaki, Makoto| Takeshita, Yuji| Kono, Iichiro|
Abstract In this paper, a numerical procedure of determining hydraulic properties in multilayered aquifers are presented. From pumping test data in multilayered aquifers, the coefficient of permeability and specific storage for each aquifer are determined by using a combination of finite element analysis and nonlinear least-squares optimization technique. This study especially points out necessity of stress-flow coupling analysis to explain the behaviors of pressure head in multilayered aquifer during pumping test. As a example, practical pumping test data were evaluate and the coefficients of permeability and specific storage of aquifers and aquitard were obtained.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-12-14
Volume volume25
Issue issue1
Start Page 99
End Page 109
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307452
JaLCDOI 10.18926/15483
FullText URL Mem_Fac_Eng_OU_24_1_107.pdf
Author Kohno, Iichiro| Nishigaki, Makoto| Takeshita, Yuji|
Abstract The numerical feasibility of determining soil water retention and hydraulic conductivity functions simultaneously from one-dimensional transient flow experiments in the laboratory by parameter estimation method is evaluated. Soil hydraulic properties are assumed to be represented by van Genuchten's closed-form expressions involving two unknown parameters: coefficients α and n . These parameters are evaluated by nonlinear least-squares fitting of predicted and observed pressure head with time. Gravity drainage experiments are performed for Toyoura standard sand to evaluate the adequacy of this proposed method.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 107
End Page 114
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307749