• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.89-94
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• 2008

Purpose: To observe the high temperature creep test and the fracture surface of the samples of 9% Ni alloy steel generally used for all kinds of mahine parts and predict the durability of that by determining a constant of C with a Larson-Miller variable. Methods: The equipment of this test was made into lever-beam style designed by Andrade and F. Garofalo et al.. The condition of creep test was set under 16 kinds of conditions after fixing 4 kinds of temperature condition and 4 kinds of stress condition to check how it effects the samples. Results: The temperature of creep test was increased, the stress index (n) of creep deformation was gradually decreased from 3.97 to 3.55. The activation energy of creep deformation was decreased from 90.39 to 83.64 kcal/mol when the stress was increased. A constant of C value by calculation of larson-Miller variable was about 22 and if temperature for use is suggested, the durability could be calculated. Conclusions: By analyzing the fracture phenomenon and suggesting the observation result of the fracture surface of the samples and creep test of 9% Ni alloy steel, the basic design data for the practical use of accessories in the field of equipment could be constructed and used to predict the durability of the equipment.

• FLOWER RESEARCH JOURNAL
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• v.19 no.4
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• pp.259-263
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• 2011

A new spray chrysanthemum (Dendranthema grandiflorum) cultivar, 'Dimple' was developed from a cross between 'champy' and 'SP05-135', by selection of seedlings and lines at the Flower Research Institute, Gyeongnam Agricultural Research and Extension Services (ARES) from 2005 to 2009. Its characteristics were investigated three times from 2007 to 2009 under condition of forcing culture in spring and retarding culture in autumn. The natural flowering time of 'Dimple' was October 24th, and year-round production was possible by day-length control. This cultivar has single type flowers with bright yellow ray floret and green center. The plant is very vigorous and very stable in the color of petals when it is cultivated even under high temperature condition in summer. Its flower was 4.7 cm in diameter, and it had 20.3 flowers per stem in autumn. The days to flowering under the short day treatment is about 50 in spring season, and 'Dimple' showed the vase life of 21.3 days in autumn. This cultivar was registered for the protection in 2009.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.155-159
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• 2005

This study was carried out to investigate the effects of cultivars and to establish the hydroponic cultivation method of spinach (Spinacia oleracea L.) f3r autumn season. Considering the rate of germination, plant height is 25 cm interior and exterior and leaf blade and petiole attitude is erect the best two cultivars 'Artlars', 'Dimple' were selected among the 19 cultivars tested. Seed germination was more than $90{\%}$ in both cultivars of 'Artlars', 'Dimple'. Seed rate of germination drops more or less, but it was cultivar that 'Mahoroba' cultivars is becoming in export standard production, and 'Premium', 'Platon' cultivar which plant height of leaf blade and petiole attitude is erect is about 20 cm was thought by suitable cultivars to domestic. Plant height relationship difference that follow to planting distances decreased according as planting distances growth than $12{\times}11$ cm to $12{\times}15$ cm. In the meantime, the increase of leaf area and fresh weight was increasing transplanting distance. The yield per ha of 14,890 kg in the $12{\times}11$ cm was $67{\%}$ increased than that in the $12{\times}9$ cm. Therefore, $12{\times}11$ cm spacing is considered optimum planting distance for spinach hydroponic cultivation in autumn season.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.2
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• pp.121-143
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• 2010

To investigate the effect of implant types and bone resorption on the fracture characteristics. 4 types of Osstem$^{(R)}$Implant were chosen and classified into external parallel, internal parallel, external taper, internal taper groups. Finite elements analysis was conducted with ANSYS Multi Physics software. Fatigue fracture test was performed by connecting the mold to the dynamic load fatigue testing machine with maximum load of 600N and minimum load of 60N. The entire fatigue test was performed with frequency of 14Hz and fractured specimens were observed with Hitachi S-3000 H scanning electron microscope. The results were as follows: 1. In the fatigue test of 2 mm exposed implants group, Tapered type and external connected type had higher fatigue life. 2. In the fatigue test of 4 mm exposed implants group, Parallel type and external connected types had higher fatigue life. 3. The fracture patterns of all 4 mm exposed implant system appeared transversely near the dead space of the fixture. With a exposing level of 2 mm, all internally connected implant systems were fractured transversely at the platform of fixture facing the abutment. but externally connected ones were fractured at the fillet of abutment body and hexa of fixture or near the dead space of the fixture. 4. Many fatigue striations were observed near the crack initiation and propagation sites. The cleavage with facet or dimple fractures appeared at the final fracture sites. 5. Effective stress of buccal site with compressive stress is higher than that of lingual site with tensile stress, and effective stress acting on the fixture is higher than that of the abutment screw. Also, maximum effective stress acting on the parallel type fixtures is higher. It is careful to use the internal type implant system in posterior area.