• The Journal of the Acoustical Society of Korea
• /
• v.27 no.2E
• /
• pp.35-44
• /
• 2008

The beat frequency is very important for the sound of Buddhist temple bells, but its concrete origins have not yet been fully clarified. In our research, we considered the beat of the bell at Hojobo Temple (Kanagawa Prefecture). Although its beat frequency has already been measured as 1.6 Hz, no satisfactory explanation has been offered for the factor that determines this value. In our previous research, we investigated the "Doza," the point where the bell is struck, and the "Obi," the vertical stripes around the bell, both of which are circumferential asymmetrical factors that can be visually recognized. Our investigations were carried out by using the Finite Element Method. These factors, however, could not sufficiently explain the beat frequency. Here, we first investigate the "Nyu," the many small projections on the bell, and the deviation between the centers of the inner and outer diameters of the bell. These two factors, however, were also found tobe insufficient explanations of the beat frequency. Through subsequent investigation, however, we finally clarified that the beat frequency's origin lies in the local dimension variation in the "Komazume," which is the bottom part of the bell as well as its thickest part.

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2005.11a
• /
• pp.106-111
• /
• 2005

For breeding of a new rootstock for eggplant production, somatic hybrids between two species, Solanum integrifolium and S. sanitwongsei were obtained through protoplast fusion. The former species has been commonly used for rootstock for eggplant production in Japan. Eggplants on these rootstocks are more productive than ungrafted plants, but are susceptible to bacterial wilt caused Ralstonia solanacearum. While the latter species is resistant, the growth of eggplants on this rootstock is rather slow and low yield. Protoplast of both species were isolated from cotyledons, and inactivated with iodoacetamide or UV-irradiation, then fused electrically. The fused products were then cultured. Regenerated plantlets were then transplanted on soil then maintained in a green house. The plants were classified into four groups. Those in the first group showed morphological characters intermediate of the parentalspecies. The plants bore fruit with viable seeds. The plants showed a chromosome number of 2n=48, the sum of those of the parental species, and are suggested to be symmetric fusion products. While plants in the other groupswas less vigorous and showed chromosome number 2n= 68 to 72 suggesting asymmetric fusion products by genomic in situ hybridization(GISH). Isozyme pattern of shikimate dehydrogenase (SKDH; EC 1.1.1.25), isocitrate dehydrogenase (IDH; EC 1.1.1.41) and phosphoglucomutase (PGM; EC 2.7.5.1) showed that 24 regenerated plants in three groups were somatic hybrids. Analysis of random amplified polymorphic DNA (RAPD) showed that 43 S. integrifolium-specific and 57 S. sanitwongsei-specific bands were all found in 24 plants. Both somatic hybrids and its S1 plants were found to be resistant to bacterial wilt, and eggplant grafted these plants using for rootstocks were more productive than grafted mother plants. Now, S1 progenies are used for commercial eggplant production in Osaka Prefecture.

• Journal of Radiation Protection and Research
• /
• v.46 no.3
• /
• pp.106-111
• /
• 2021

Background: Crookes tube is utilized in junior high and high schools in Japan to study the character of electrons and current, and not for radiological education. There is no official guideline or regulation for these radiation source to the public. Therefore, most teachers have no information about the leakage of X-rays from Crookes tube. The peak energy of X-rays is approximately 20 keV, and it is impossible to measure using conventional survey meters. Materials and Methods: Each leakage dose of low energy X-rays from 38 Crookes tube in the education field, such as junior and senior high schools in Japan, was explored by the teachers in the school using radio-photoluminescence (RPL) dosimeters. Before and after the measurements, the dosimeters were sent by postal mails. Results and Discussion: At the exploration in this study, it was estimated that the 70 ㎛ dose equivalent, H_p(0.07) of X-rays from 31 Crookes tubes were smaller than 100 µSv in 10 minutes, at the distance of 1 m, where the Crookes tube was usually observed. However, the highest dose was estimated as 0.69 mSv by an equipment with the full power. Furthermore, one Crookes tube exhibited 0.62 mSv with minimum output power of the induction coil. This relatively large dose was reduced by the shorter distance of discharge electrodes of the induction coil. Conclusion: The leakage dose of low energy X-rays from 38 Crookes tube was explored using RPL dosimeters. It was estimated that the H_p(0.07) of X-rays from 31 Crookes tubes were smaller than 100 µSv in 10 minutes at the distance of 1 m, while some equipment radiated a higher dose. With this study, the provisional guideline for the safety operation of Crookes tube is established.

• Proceedings of the KWS Conference
• /
• 2002.10a
• /
• pp.726-731
• /
• 2002

Reaction synthesis is a process to form ceramics, intermetallics and their composites from elemental powder mixture. Application of this process to a surface modification techniques has a possibilities to enable the process at a lower temperature or for a shorter time, although synthesized materials are likely to include voids and unreacted elements. This paper intend to examine the effect of Si addition to the mixture of Al and Ni on the densification of synthesized Ni-Al intermetallic compounds and to evaluate the surface properties of obtained coatings. By the Si addition, exothermic reaction temperature to form Ni-Al intermetallic was lowered to be below the melting point of Al. Si soluted $Al_3$Ni$_2$, $Al_3$Ni and $Al_{6}$Ni$_3$Si were mainly formed in the coating layer when powder mixture was heated to 973K for 300s. Besides, densification was enhanced by increasing hot press pressure, Si additions and heating rate. When the composition of eutectic Al-Si reaches 78%, void ratio of sintered compact reduced to 0.4%. It is caused by higher flowability of Al-Si liquid phase generated and its infiltration into the void. Since the hardness of NiAl(Si) compound (about 600HV) formed in the coating layer is higher than that of Ni-Al compound (about 400HV), coating layer with high density and superior wear property is obtained by hot press using reaction synthesis from Al-Ni-Si powder mixture.

• Journal of the Korean Magnetic Resonance Society
• /
• v.6 no.2
• /
• pp.84-88
• /
• 2002

Dating and dosimetry using electron spin resonance (ESR) in 20th Century developed at both Yamaguchi University and Osaka University have been reviewed with emphasis on new prospects and strategies in 21th century. Natural radiation have been generating radicals that accumulated in archaeological and geological materials. ESR detects these radicals and the ESR signal intensity is proportional to the radiation dose and therefore the age. The assessment of the total dose of natural radiation and the annual dose rate give their ESR ages. The ESR dating of stalactites and stalagmites ant Akiyoshi cave in Yamaguchi prefecture in 1975 was extended to anthropological dating using bones and tooth enamel excavated in Greek Petralona cave. Fossils of shells and corals gave the ages of marine terraces and sea-level changes. Quartz grains gave the ages of geothermal alteration and fault movements. Future ESR dating of ices at outer planets anf their satellite are also investigated as basic studies for ices od $H_2O,\;CO_2,\;SO_2$ as well as terrestrial hydrates in laboratory. Atomic bomb radiation dosimetry at Hiroshima and Nagasaki using ESR lead to the dosimetry of personnel, Chemobyl and JCO criticality accidents. Monitoring of radiation dose with sensitive materials with tissue equivalence are being developed. finally a new scanning ESR imaging apparatus (a near field microwave microscope) developed in our laboratory gave ESR images of Radicals from fossils to Si-CVD and diamond films as summarized in my book in 2002.

• Korean journal of applied entomology
• /
• v.22 no.3 s.56
• /
• pp.213-227
• /
• 1983

Thirteen species distributed over 3 genera of the subfamily Lithocolletinae are reported from Korea. Of them 8 species are new to the Korean fauna. Two genera, Hyloconis and Chrysaster, are recorded from the Asian continent for the first time. Fore wings of all the species and male and female genitalia of some ones are illustrated. Besides these Korean species, one North American species, Argyromiges ostensackenella Fitcher, 1859, is newly transferred to the genus Chrysoster.

• Journal of Environmental Science International
• /
• v.13 no.2
• /
• pp.167-173
• /
• 2004

A aqueous solution of malodorants (i.e., n-valeraldehyde, n-valeric- acid, 2-methylisoborneol, and trimethylamine) was exposed to 200KHz ultrasound with a power of 6.0W/$\textrm{cm}^2$ per unit volume in a sonochemical reactor under room temperature and atmospheric pressure condition. The concentration of malodorants decreased with irradiation time, indicating pseudo-first-order kinetics. The removal efficiency of malodorants was about from 50% to 96% decomposed after 90 minutes sonication. At the deodorization, it was determined by triangle odor bag(TOB) method for odor sensory measurement, and it indicated that over 60% of relative odors were deodorized with degradation by the sonication.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2000.11c
• /
• pp.607-612
• /
• 2000

Microprecision agriculture for a fully controlled plant factory is proposed in this paper. Microprecision agriculture can be attained by using plant factories to realize profitable alternative agriculture. A closed, fully controlled, plant-growing factory is far better in terms of minimizing all sorts of waste. The limit and optimum design concept has to be applied to establish an economically feasible, fully controlled, plant-growing factory. To achieve this objective, microprecision technologies have to be developed. Microprecision technologies should be involved in sensing, modeling, controlling, and collecting information for the mechatronics for plant production. Basic technologies for microprecision are already available; they are SPA (speaking plant approach to environmental control), AI (artificial intelligence: expert systems, neural networks, genetic algorithms, photosynthetic algorithms etc.), bioinstrumentation, non-invasive measurement, biomechatronics, and biorobotics. A microprecision irrigation system for plug production is an example of a microprecision technology that has actually been implemented in a plug seedling production factory.

• Journal of Plant Biotechnology
• /
• v.4 no.4
• /
• pp.135-141
• /
• 2002

Agrobacterium-mediated transformation has been unsuccessful for monocot plants except for a few important crops such as barley, rice, maize and wheat. We discussed here that a successful transformation of monocots demands certain critical conditions. The requirements for an efficient transformation are a selection of target tissues competent for plant regeneration and Agrobacterium-infection, and various factors promoting Agrobacterium-infection. The factors were divided into two to activate Agrobacterium and to increase plant cell's susceptibility against Agrobacterium. Optimization of these factors significantly increased transformation efficiency of zoysia grass and rice plants. A technical improvement in transformation system for monocots will promote improvement of the breed as well as a study of gene functions in monocots.

• Agricultural and Biosystems Engineering
• /
• v.1 no.1
• /
• pp.22-29
• /
• 2000

The development of bio-response feedback control system known as the speaking plant approach has been a challenging task for plant production engineers and scientists. In order to achieve the aim of developing such a bio-response feedback control system, the primary concern should be to develop a practical non-invasive technique for monitoring plant growth. Those who are skilled in raising plants can sense whether their plants are under adequate water conditions or not, for example, by merely observing minor color and tone changes before the plants wilt. Consequently, using machine vision, it may be possible to recognize changes in indices that describe plant conditions based on the appearance of growing plants. The interpretation of image information of plants may be based on image features extracted from the original pictorial image. In this study, the performance of a finite element retina was optimized by a genetic algorithm. The optimized finite element retina was evaluated based on the performance of neural plant growth monitor that requires input data given by the finite element retina.