• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.581-584
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• 2014

Skin is the soft outer covering of vertebrates. In mammals, the skin is the largest organ of the integumentary system made up of multiple layers of ectodermal tissue, and guards the underlying muscles, bones, ligaments and internal organs. There is a difference of the physiological function and anatomical structure of the skin, as body parts, sex, age, race and nutritional status. In this study, we measured the moisturizing ability of the skin of the 20s Chinese and Korea in Korean. We found that the skin hydrating of Chinese is significantly higher than Korean and TEWL of Chinese is lower than Korean. We measured the moisturizing ability of both 20s Chinese and Korean. As result, the moisturizing ability of 20s Chinese is better than Korean.

• Economic and Environmental Geology
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• v.43 no.6
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• pp.555-564
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• 2010

Remediation process by using the bio-carrier (beads) with dead Bacillus sp. B1 and polysulfone was investigated for heavy metal contaminated groundwater. Sorption batch experiments using the bio-carrier were performed to quantify the heavy metal removal efficiencies from the contaminated solution. The analyses using SEM/EDS and TEM for the structure and the characteristic of precipitates on/inside the beads were also conducted to understand the sorption mechanism by the bio-carrier. Various amounts of freeze-dried dead Bacillus sp. B1 were mixed with polysulfone + DMF(N,N-dimethylformamide) solution to produce the bio-carrier (beads; less than 2mm in diameter) and 5% of Bacillus sp. B1 in the bio-carrier was optimal for Pb removal in the solution. The removal efficiency ratings of the bio-carrier for Pb, Cu and Cd were greater than 80% after adding 2g of bio-carrier in 50ml of aqueous solution (<10mg/L of each heavy metal concentration). Reaction time of the bio-carrier was very fast and most of the sorption reaction for heavy metals were completed within few hours. Batch experiments were duplicated at various pH conditions of aqueous solutions and Cu and Pb removal efficiencies highly maintained at wide pH ranges (pH 2-12), suggesting that the bio-carrier can be useful to clean up the acidic waste water such as AMD. From SEM/EDS and TEM analyses, it was observed that the bio-carrier was spherical shape and was overlapped by many porous layers. During the sorption experiment, Pb was crystallized on the surface of porous layers and also was mainly concentrated at the boundary of Bacillus sp. B1 stroma and polysulfone substrate, showing that the main mechanism of the bio-carrier to remove heavy metals is the sorption on/inside of the bio-carriers and the bio-carriers are excellent biosorbents for the removal of heavy metal ions from groundwater.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.1
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• pp.1-8
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• 2016

The purpose of this study is to predict the cracking behavior and suggest the method of controlling the cracking in concrete box culvert for power transmission due to differential drying shrinkage. Drying shrinkage cracking is mainly influenced by the moisture diffusion coefficient that determines moisture diffusion rate inside concrete structures. In addition to the diffusion coefficient, surface coefficient of concrete surface and relative humidity of ambient air simultaneously affect the moisture evaporation from concrete inside to external air outside. Within the framework of drying shrinkage cracking mechanism, it is necessary to perform the numerical analysis, which involves these three influencing factors to predict and control the shrinkage cracking of concrete. In this study, moisture diffusion and stress analysis cor responding to drying shrinkage on concrete box culvert are performed with consideration of diffusion coefficient, surface coefficient, and relative humidity of ambient air. From the numerical results, it is found that cracking behavior due to differential drying shrinkage of box culvert shows the different feature according to three influencing factors and the methodology of controlling of drying shrinkage cracks can be suggested from this study.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4A
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• pp.329-335
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• 2009

The purpose of this study is to provide the efficient method and guideline of controlling the cracking in bridge deck concrete due to differential drying shrinkage. Drying shrinkage cracking is mainly influenced by the moisture diffusion coefficient that determines moisture diffusion rate inside concrete structures. In addition to the diffusion coefficient, surface coefficient of concrete surface and relative humidity of ambient air simultaneously affect the moisture evaporation from concrete inside to external air outside. Within the framework of cracking shrinkage cracking mechanism, it is necessary to conceive the numerical analysis, which involves these three influencing factors to predict and control the shrinkage cracking of concrete. In this study, moisture diffusion and stress analysis corresponding to drying shrinkage on bridge deck are performed with consideration of diffusion coefficient, surface coefficient, and relative humidity of ambient air. From the numerical results, it is found that cracking behavior due to differential drying shrinkage of bridge deck concrete shows different feature according to three influencing factors and the methodology of controlling of drying shrinkage cracks can be suggested from this study.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.7
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• pp.539-549
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• 2017

In this paper, experimental studies on the shroud separation were performed to investigate characteristics of the shroud separation at mach 3. Shroud separation tests were carried out in the vertical free-jet wind tunnel that is capable of testing separable structures. A shroud model was miniaturized to meet test objectives and test section dimensions of the wind tunnel. Pneumatic Locking and separation mechanisms were designed considering external force due to free stream. High speed cameras were used to record the shroud motion and unsteady shock patterns over the deploying shrouds during the shroud separation process. Also, unsteady pressures on the nose surface were measured by using the pressure sensors. Through the tests, the measurement data necessary for researches on the shroud separation technology were obtained. Shroud separation behaviors and characteristics of unsteady pressure on the nose surface for each external flow conditions were analyzed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.4
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• pp.68-72
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• 2004

In this paper, the energy conversion theory of the linear actuator deals with the temperature characteristic analysis with verifying temperature of linear Actuator system This model of linear actuator has winding part and mechanical spring, and a plunger. This paper proposed and experimented the linear Actuator(LA) by using finite difference equation(FDE). The experimental result represented the temperature T1 and T2 which remarks Tl is a center of magnetic road inside of actuator winding part, and T2 is a surface of actuator winding part. And the temperature characteristic of the actuator winding part are experimented by the digital temperature meter TECPEL 322.

• Korean Journal of Plant Taxonomy
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• v.44 no.3
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• pp.191-201
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• 2014

In order to find useful taxonomic morphological characters, 17 taxa from East-Asia Astragalus and Oxytropis anertii were investigated. In this study, seed coat structure, fruit surface, and fruit anatomical structures were selected to classify the species in Astragalus. As a results, useful morphological and anatomical characters in East-Asia Astragalus were life cycle, leaflet shape, raceme, petal color, seed color, pod shape, absent or present of hairs in pod surface, bent degree of dorsal suture, and thickness of endocarp. Using medicinal sources in China, A. floridus, A. membranaceus, A. membranaceus var. mongholicus and A. tongolensis were formed same group. However, these were not completely consensus in the morphological characters. The other hand, A. koraiensis and A. sikokianus, which have controversial taxonomic issue, have clearly no differences morphological characters each other. Therefore, A. koraiensis, A. sikokianus, and A. bhotanensis should be conducted a comparative study on the DNA sequences and molecular cytology in order to clarify the taxonomic treatments in the near future.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.616-622
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• 2015

Current ballast water treatment technologies are applying chemical or electrical treatment technology which are not free from secondary environmental pollution. The purpose of this study is to treat the ballast water by shear stress without an additional environmental pollution and to find out the optimal treatment apparatus. We tried to treat ballast water by applying shear stress with two different type of combination of inner and outer cylinder, such as non-pattern type and groove type. In the case of non-pattern type of inner and outer cylinder, sterilization effect was comparatively low because of a slip between inner and outer cylinder. But in the case of groove type of inner and outer cylinder, sterilization effect was superior to the non-pattern type. With a same revolutional speed of 8000rpm, an extinction effect was acquired in the gap of 1 mm of inner and outer cylinder at non-pattern type, but 3mm of that of groove type.

• Korean Journal of Plant Resources
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• v.33 no.2
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• pp.116-129
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• 2020

The genus Sedum comprises about 400 taxa with worldwide distribution, and about 20 taxa of the genus Phedimus distributed from Asia to Europe. According to some taxonomists, Phedimus and Sedum are two separate genera of the family Crassulaceae; however, in Korea Phedimus has been treated as a subgenus Aizoon within the genus Sedum. This ambiguous taxonomic treatment of the genus Phedimus needs further confirmation. In the study, we investigated morphological characteristics such as the whole plant height, leaf morphology, and seed coat features of these two genera. We believe that these characters are very important to distinguish Phedimus and Sedum. The result indicated that the seed surface pattern was the most useful diagnostic character. The Sedum had a hexagonal pattern with a single nipple protrusion, whereas the Phedimus had a rectangular pattern with papilla on both ends. The results of this study strongly support the separation of Phedimus from Sedum and thus Phedimus need to be treated as an independent genus.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1567-1569
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• 2001

자유 도전성 파티클이 전계의 영향으로 GIS (Gas Insulated Switchgear) 외함전극 내부표면으로부터 가스공간을 가로질러 중앙도체까지 튀어 오르게 되면 절연파괴가 발생할 가능성이 매우 높아진다. 그러므로 파티클이 튀어 오르는 높이는 절연파괴 발생 위험도를 평가하는 데에 중요한 자료로 활용될 수 있다. 본 논문에서는 GIS 내부에 자유 도전성 파티클이 혼입된 상태에서 GIS가 운전중일 때 GIS 외부에서 파티클 상승높이를 추정하는 방안을 세계 최초로 제시함으로써 현재까지 해결되지 않은 도전성 파티클 결함에 대한 절연파괴 위험도 평가가 가능하게 되었다.