| JaLCDOI | 10.18926/15473 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_26_2_61.pdf |
| Author | Osaka, Akiyoshi| Kawabata Kouji| Nanba, Tokuro| Takada, Jun| Miura, Yoshinari| |
| Abstract | Mullite-dispersed silica ceramics were prepared through sol-gel processing by the use of tetraethoxy silane, aluminium nitrate and aluminium isopropoxide as the Si and Al sources where HCl and HN0(3) were the catalyst. Effect of the starting materials, solvents and catalysts was examined on the gelation time or temperature of mullite precipitation. Apparent activation energy of gelation ranged from 80 to 95kJ/mol. The presence of AI in the sols elongated the gelling time suggesting the formation of chelate bonds between AI and Si-OR or Si-OH bonds. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1992-03-28 |
| Volume | volume26 |
| Issue | issue2 |
| Start Page | 61 |
| End Page | 67 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307416 |
| JaLCDOI | 10.18926/15445 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_26_2_139.pdf |
| Author | Hirose, Sohichi| |
| Abstract | Scattering problems by a penny-shaped crack are solved using a time-domain boundary integral equation method, The crack is located in an infinite homogeneous, isotropic, linearly elastic solid, and is subjected to an oblique incident wave of either P-, SV-, or SH-wave, The hypersingular integral equation is solved to obtain near-field solutions as well as scattered far-fields. The accuracy of the present method is confirmed by comparing the near-field solutions for different arrangement of elements, Scattered far-fields are calculated for various incident waves, and their usefulness in quantitative non-destructive evaluation is discussed. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1992-03-28 |
| Volume | volume26 |
| Issue | issue2 |
| Start Page | 139 |
| End Page | 150 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307492 |
| JaLCDOI | 10.18926/15444 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_26_2_129.pdf |
| Author | Totsuji, Hiroo| |
| Abstract | The spectrum of Schottky noise in ion storage rings is analyzed as density fluctuations in effectively one-dimensional plasmas. Strong coupling effects in these plasmas are discussed in relation to experimental observations. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1992-03-28 |
| Volume | volume26 |
| Issue | issue2 |
| Start Page | 129 |
| End Page | 138 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307668 |
| JaLCDOI | 10.18926/15443 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_26_2_111.pdf |
| Author | Nara, Shigetoshi| Banzhaf Wolfgag| |
| Abstract | An information processing task which generates combinatorial explosion and program complexity when it is treated by a serial algorithm is investigated using both Genetic Algorithms (GA) and a neural network model (NN). The task in question is to find a target memory from a set of stored entries in the form of "attractors" in a high dimensional state space. The representation of entries in the memory is distributed ("an auto associative neural network" in this paper), and the problem is to find an attractor under a given access information where the uniqueness or even existence of a solution is not always guaranteed ( an ill-posed problem ). The GA is used as an algorithm for generating a search orbit to search effectively for a state which satisfies the access condition and belongs to the target attractor basin in state space. The NN is used to retrieve the corresponding entry from the network. The results of our computer simulation indicate that the present method is superior to a search method which uses random walk in state space. Our technique may prove useful in the realization of flexible and adaptive information processing, since pattern search in high dimensional state spaces is common in various kinds of parallel information processing. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1992-03-28 |
| Volume | volume26 |
| Issue | issue2 |
| Start Page | 111 |
| End Page | 128 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307718 |
| JaLCDOI | 10.18926/15441 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_26_2_93.pdf |
| Author | Fukuyama, Atsushi| Kasai Takashi| Furutani, Yoichiro| |
| Abstract | A one-dimensional tokamak transport code (TASK/TR) has been developed to analyze the evolution of a burning plasma accompanied with fusion reaction. This code deals with the electrons, deuterons, tritons, thermalized α particles, fast α particles and beam ions, separately, in order to describe the dependence of the reaction rate on the ion mixture ratio. As an energy transport model, the drift wave turbulence mode is employed. The heating and current drive by the neutral beam injection as well as the pellet injection for fuelling are also included. This code is applied to a reactor-grade plasma aimed at in the ITER project. The cases of an ignited plasma and a current-driven plasma are examined. The required power for full current drive is estimated. The effect of pellet injection, both fuel and impurity ions, is also studied. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1992-03-28 |
| Volume | volume26 |
| Issue | issue2 |
| Start Page | 93 |
| End Page | 109 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307699 |
| JaLCDOI | 10.18926/15439 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_26_2_77.pdf |
| Author | Wada, Osami| Nakajima Masamitsu| |
| Abstract | This paper describes a method to design an antenna to focus millimeter-wave beam generated by a gyrotron. The antenna, which has been proposed by the authors, consists of a stair-cut circular waveguide and two cylindrical reflectors; one is elliptic and the other is parabolic. Its principle is based on the geometrical optics though slightly modified to consider the diffraction effect. Results of low-power experiments agree well with the design on beam direction, beam width and the position of the focal point. At 35.5 GHz using TE(01) mode, a focused beam with half-power thickness of 13 mm x 10 mm was obtained. This type of antennas find applications to millimeter-wave scattering measurement in fusion plasma research and high- energy-density source for material heating. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1992-03-28 |
| Volume | volume26 |
| Issue | issue2 |
| Start Page | 77 |
| End Page | 92 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307321 |
| JaLCDOI | 10.18926/15436 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_26_2_69.pdf |
| Author | Fujii, Tatsuo| Sakata Naoki| Nanba, Tokuro| Osaka, Akiyoshi| Miura, Yoshinari| Takada, Jun| |
| Abstract | (001)-oriented Ti(2)O(3) films were epitaxially grown on a(001)-face of sapphire single-crystalline substrate by an activated reactive evaporation method. The formation ranges of stoichiometric and nonstoichiometric Ti(2)O(3) films were determined as a function of the substrate temperature (Ts), the oxygen pressure (Po(2)) and the deposition rate. Stoichiometric Ti(2)O(3) films were grown at Ts≧673K under Po(2)≧1.0×10(-4)Torr, which showed the metal-insulator transition with a sharp change in electrical resistivity from 3.5×10(-2) to 2.6×10(-3)Ωcm at 361K. Nonstoichiometric films prepared under less oxidized conditions did not exhibit the transition. The nonstoichiometry of the Ti(2)O(3)films was discussed in terms of excess Ti ions. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1992-03-28 |
| Volume | volume26 |
| Issue | issue2 |
| Start Page | 69 |
| End Page | 75 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307639 |
| JaLCDOI | 10.18926/15429 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_26_2_25.pdf |
| Author | Matsuda, Masaaki| Osaki, Hirokazu| |
| Abstract | The eye movement has been studied widely, because it gives various information about the characteristics of visual work. Almost all of those studies have concentrated on the distribution of the visual points, the direction and width of the saccadic movement and the fixation time of the measures. However there are few measures to evaluate the relationship between the visual objects and eye movement. Recently, the personal computer become portable and this makes it possible to analyze the many data and to show the results graphically on the experimental field. In this study, we propose a series of methods to evaluate how a subject looks at a visual field using the queue theory, and how often man looks at the central part of the visual field using the statistical two-dimensional ellipse. We developed the Pascal program on an personal computer(NEC PC9800). This program has 3 functions. One is the measurement of eye movement, the second is the calculation of the proposed measures and the third is the display of the results of these calculations. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1992-03-28 |
| Volume | volume26 |
| Issue | issue2 |
| Start Page | 25 |
| End Page | 41 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002308015 |
| JaLCDOI | 10.18926/15427 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_26_2_17.pdf |
| Author | Feng Yibu| Inaba, Hideo| Nozu, Shigeru| |
| Abstract | Heat transfer measurements were conducted during freezing of quiescent water in a horizontal cylinder. A horizontal cylinder with inner diameter of 61.1 mm is cooled by air in a constant low temperature room and time variations of the radial distribution of fluid temperature were observed. Experimental results for the velocity of the phase change interface, the time taken for complete freezing and apparent freezing heat transfer coefficient were compared with the simple theoretical model based on the quasisteady assumption. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1992-03-28 |
| Volume | volume26 |
| Issue | issue2 |
| Start Page | 17 |
| End Page | 24 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307382 |
| JaLCDOI | 10.18926/15425 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_26_2_1.pdf |
| Author | Inaba, Hideo| Otake, Hideo| Nozu, Shigeru| |
| Abstract | Radiative characteristics of the frost layer melted by radiative heat are experimentally examined. A frost layer is heated from above by the radiative heat from a halogen lamp set. Thermal radiation of the lamp has the wavelength spectrum characteristics similar to those of the solar radiation. The effect of the environmental temperature upon the frost melting process is clarified in experiments. The optical characteristics of reflectivity, absorptivity and transmissivity of the frost layer during the melting of the frost layer are measured using special measuring instruments. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1992-03-28 |
| Volume | volume26 |
| Issue | issue2 |
| Start Page | 1 |
| End Page | 16 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307428 |
