• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.6
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• pp.367-380
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• 2014

Tsunami take away life, wash houses away and bring devastation to social infrastructures such as breakwaters, bridges and ports. The targeted coastal structure object in this study can be damaged mainly by the tsunami force together with foundation ground failure due to scouring and liquefaction. The increase of excess pore water pressure composed of oscillatory and residual components may reduce effective stress and, consequently, the seabed may liquefy. If liquefaction occurs in the seabed, the structure may sink, overturn, and eventually increase the failure potential. In this study, the solitary wave was generated using 2D-NIT(Two-Dimensional Numerical Irregular wave Tank) model, and the dynamic wave pressure acting on the seabed and the estimated surface boundary of the vertical revetment. Simulation results were used as an input data in a finite element computer program(FLIP) for elasto-plastic seabed response. The time and spatial variations in excess pore water pressure, effective stress, seabed deformation, structure displacement and liquefaction potential in the seabed were estimated. From the results of the analysis, the stability of the vertical revetment was evaluated.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.4
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• pp.423-428
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• 2016

The last stage blades of a low pressure (LP) turbine get frequently fractured because of stress corrosion cracking. This is because they operate in a severe corrosive environment that is caused by the impurities dissolved in condensed steam and high stress due to high speed rotation. To improve the reliability of the blades under severe conditions, 12% Cr martensitic stainless steel, having excellent corrosion resistance and higher strength, is widely used as the blade material. This paper shows the result of root cause analysis on a blade which got fractured suddenly during normal operation. Testing of mechanical properties and microstructure examination were performed on the fractured blade and on a blade in sound condition. The results of testing of mechanical properties of the fractured blade showed that the hardness were higher but impact energy were lower, and were not meeting the criteria as per the material certificate specification. This result showed that the fractured blade became embrittled. The branch-type crack was found to have propagated through the grain boundary and components of chloride and sulfur were detected on the fractured surface. Based on these results, the root cause of fracture was confirmed to be stress corrosion cracking.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.60-68
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• 2007

This study was perform to examine the feasibility of cooking processing using the rice added the 70% ethanol extract of pigmented rice bran layer. Four rice samples, including normal rice, glutinous rice, pigmented-normal rice, and pigmented-glutinous rice were compared the properties of physico-chemical, texture, and sensory evaluation. Pigmented rice varieties had a higher amylose content, but shorter length in glucose chains than non-pigmented rice varieties. The enthalpy for gelatinization was found to increase in pigmented rice, which need more energy for gelatinization of starch in cooking. The hydrolysis rate by glucoamylase in rice added pigmented bran extract was higher than pigmented rice. Rice with pigmented bran extract had higher glutamine content, but lower asparagine content and no difference in fatty acid composition, which affect palatability. Cooked rice added pigmented bran extract was less retrograded than pigmented rice during the storage period. Moreover, cooked rice added pigmented bran extract was more acceptable in sensory evaluation. Based on the results, the use of rice added pigmented bran extract instead of pigmented rice in grain processed food have advantageous effects in palatability of polished rice and phytochemicals of pigmented non-polished rice. This study will help develop new health-promoting rice products.

• Journal of the Society of Disaster Information
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• v.14 no.2
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• pp.107-114
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• 2018

Purpose : This study is to develop walls using wall recording technology applied on roofs to prevent fire spread in traditional markets. Method : The spray head installed on the developed wall was designed so that the fire does not spread to adjacent buildings after being used for plants. In addition, a spray head was attached to the upper section and some sections for the growth of plants planted on the wall to prevent the spread of fire. Results : These technologies suggested the development of walls that can be installed at the upper level of buildings, such as traditional markets, and separate isolation facilities were not necessary because they are integrated with structures and sprinklers. In addition, sprinklers can perform both the plant spray and fire spread prevention functions. It is believed that this is the only alternative technology proposed in Korea to prevent the spread of fire. Conclusion : In this study, the wall design, designed directly to derive the quantitative performance of the fire spread reduction effect, demonstrated the fire suppression method of the wall system, the durability of the wall itself, and the flame retardability performance.

• Korean Journal of Ecology and Environment
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• v.44 no.3
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• pp.280-291
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• 2011

Bottom-up approaches to control of Microcystis aeruginosa blooms were comparatively investigated through an in situ mesocosm experiment using aquatic plants (Iris pseudoacorus). In the mesocosm experiments, floating I. pseudoacorus, seemed to be effective in controlling massive M. aeruginosa blooms in an agricultural reservoir, exhibiting a close coupling with temporal variations in Chl-a and DO concentration. Shading by floating I. pseudoacorus resulted in a reduced phytoplankton abundance inhibiting light energy availability. Moreover, I. pseudoacorus may suppress phytoplankton growth through the excretion of chemical substances, likes a allelopathy, that inhibit phytoplankton photosynthetic activity. The $^{15}N$ atom % of I. pseudoacorus showed higher values than POM, suggesting that I. pseudoacorus assimilates DIN predominantly compared to phytoplankton, which was mostly M. aeruginosa. This result strongly suggests that the M. aeruginosa bloom should be regulated by aquatic plants, like I. pseudoacorus, this approach can affect zooplankton composition. This is the first study that has used stable isotope tracers to evaluate the biomanipulation efficiency through floating I. pseudoacorus.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.507-511
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• 2005

울돌목은 조류발전의 세계적인 최적지로 꼽히고 있으며 서해와 남해의 점이 지대로서 조류에 의해 해양 생물 군집의 대량 이동이 빈번한 곳이라 할 수 있다. 조류 발전 시설인 터빈의 가동은 물리적인 충격에 의해 해양 생물의 생태-생리 반응에 영향을 미칠 가능성이 있다. 네트를 이용한 1차 조사에서 터빈 가동에 의한 동물플랑크톤의 순 사망률은 $44.3\%$로 나타났다. 1차 조사 이 후 다이아프램 펌프를 이용한 조사 결과 중 출현 개체수가 높았던 조사에서 전체 동물플랑크톤의 순 사망률은 각각 $7.3\%,\;5.8\%$를 나타내었고, 요각류는 각각 $4.4\%,\;5.2\%$를 나타냈다. 물리적인 충격을 인위적으로 가한 실험에서 스트레스를 받은 요각류 Acartia hongi의 알 생산은 스트레스를 받지 않은 것보다 $1.8\~2.3$배 낮은 경향을 보였다. 본 조사에서 동물플랑크톤이 낮은 사망률을 보골 이유는 작은 크기의 생물이 우점하였기 때문이며 조사 결과에서 몸체가 비교적 단단하고 크기가 작은 요각류는 상대적으로 약한 부유유생보다 높은 생존율을 보였다. 울돌목 조사 해역에서 출현한 동물플랑크톤은 크기가 작아 터빈의 물리적인 충격에 의한 사망률은 낮을 수 있으나 순간적으로 강한 스트레스를 받는다면 재생산을 포함한 생리활동이 저하될 수 있음을 보였다. 네트 및 펌프를 이용한 조사 결과에서 네트에 의한 채집은 터빈의 영향뿐만 아니라 빠른 유속으로 인하여 네트가 받는 압력에 의해 생물체가 손상되는 양상이 높아 사망률이 높았던 것으로 보인다. 그러나 다이아프램 펌프는 생물 채집 시 오류를 최소화하는 장점은 있으나 채집의 장시간에 비해 매우 적은 생물량이 채집되는 단점을 보였다TEX>$96.5\%$에 미달하는 문제는 식물성 원료유로 제조한 고순도 바이오디젤과 혼합 사용하거나 감압 증류 공정을 통해 고농도의 폐식용유 바이오디젤을 제조하여 해결 가능하다. 대전시 신성동 소재의 음식점에서 수거한 폐식용유를 원료로 하여 생산한 바이오디젤의 차량 배출가스 실증 테스트 결과 경유 차량의 주 오염물질인 PM과 Soot 및 기타 오염물질의 배출량은 감소하였으나 NOx의 배출량은 약간 증가하는 것으로 나타났다구와 이해를 바탕으로 보존대책이 마련되어야 한다.되었다. 이런 모든 시편들을 각 탈염방법에 따라 탈염처리한 후 XRD와 SEM-EDS으로 분석한 결과 인철광과 침철광은 어떠한 변화도 보이지 않았고, 다만 적금광으로 동정된 시편만이 잔존하지 않았다. 철기 제작별 $Cl^-$ 이온 추출량과 탈염효과에 대한 비교 실험은 이온 크로마토그래피 분석 결과와 마찬가지로 단조 철제유물이 주조 철제보다 $Cl^-$ 이온을 많이 가지고 있었으며, 탈염 처리 후에는 $Cl^-$ 이온은 전혀 발견되지 않았다. 이상의 결과 $K_2CO_3$와 Sodium 용액은 탈염처리에서 가장 적합한 탈염처리 용액으로 알수가 있었으며 특히 어떠한 탈염 용액으로 유물을 처리한다 해도 철제유물에 생성된 부식물은 제거되지 않는다는 것을 알게 되었다. 따라서 보존처리자는 유물 표면의 부식 상태만을 보고 처리하기 보다는 철기제작물로 고려하여 처리하는 것이 필요하다. 또한 금속에 부식을 야기시키는 $Cl^-$ 이온과 부식물을 완전하게 제거하여 탈염처리를 하는 것이 유물 부식을 최대한 지연시킬 수 있는 것이라 생각된다.TEX>$88\%$)였다.(P=0.063). 결론: 본

• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.4
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• pp.294-303
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• 2005

This paper describes the analysis results of a series f Round-Robin test that was performed to intercompare inspection and diagnosis techniques for characterization of pressure tube f a pressurized heavy water reactor under the Coordinated Research Project(CRP) of IAEA's nuclear Power Programme. For this test, six nations, Korea, Canada, India, Argentina, Rumania, and China that currently have pressurized heavy water reactors under operation involved, and the "KOR-1" pressure tube sample prepared by Korea was used. Two kinds of NDE technique, ultrasonic and eddy current test, were applied for these tests. The "KOR-1" pressure tube sample contains total 12 artificial flaws such as crack-like EDM notches, wear that is similar to the real flaws and can be produced on the pressure tubes during plant operation. Test results showed that seven laboratories from six nations detected all twelve flaws in "KOR-1" specimen by using ultrasonic and eddy current test methods, and ultrasonic test method was more accurate than eddy current test method in flaw detectin and sizing. ID flaws in pressure tube sample were more easily detected and accurately sized than OD flaws.

• Korean Journal of Medicinal Crop Science
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• v.23 no.6
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• pp.468-472
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• 2015

Background : Chinese matrimony vine (Lycium chinense Mill.) is a deciduous shrub belonging to the Solanaceae. The leaves are used as an alternative raw material replacing dried fruits associated with high production costs in many industires. The aim of this experiment was to determine the effect of drying temperature on the leaves used in the manufacture of functional products. Methods and Results : The leaves of Chinese matrimony vine were harvested when the plant height reached 60 - 70 cm in the spring and treated at four different temperatures ($40^{\circ}C$, $50^{\circ}C$, $60^{\circ}C$ and $70^{\circ}C$). The time to reach the desiccation state of 20% was 63 h at $40^{\circ}C$, 37 h at $50^{\circ}C$, 17 h at $60^{\circ}C$ and 11 h at $70^{\circ}C$. The drying rate per hour was 1.28% at $40^{\circ}C$, 2.25% at $50^{\circ}C$, 4.94% at $60^{\circ}C$ and 7.60% at $70^{\circ}C$. No significant difference were observed in ash, crude fat, polyphenol or rutin content of treated samples. Crude protein and betaine content decreased with higher dry temperatures. Nitrogen free extract of the treated samples increased with higher drying temperatures. Conclusions : Taking into consideration drying time, drying rate, color value, energy consumption and functional ingredients is advantageous to dry the leaves of the Chinese matrimony vine at $60^{\circ}C$ using a hot air agricultural dryer.

• Korean Journal of Oriental Medicine
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• v.16 no.3
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• pp.167-173
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• 2010

Objects : Glycine max Merr. (black bean), Triticum aestivum L. (wheat) and Oryza sativa L. (rice bran) have been widely used for treatment of relaxion of smooth muscle, gastrointestinal hemorrhage and alopecia in Korean Traditional Medicine. In this research, we examined the effect of the extracts, obtained from EtOH extracts of 3 kinds of traditional plants, on hair growing activity of the DP6 and C3H10T1 cell and physical properties. Materials and Methods : On the basis of previous studies, three traditional plants were selected and we extracted them with ethanol. We evaluated their hairy dermal papillar cell proliferation activity and mouse mesenchymal stem cell in vitro model. Also, 3 herbal extracts were added to the normal shampoo formulation in ranges of 0.1% and we validated tensile properties and physical changes using aged hair. In this research, we compared the tensile strength, shine and color appearance between the hair (general formulation) and the hair after applying shampoo with natural extracts. To analyze the luster and color image, we use the SAMBA hardware and software made by Bossa Nova Technologies. Results : In the comparative test for tensile characteristic between the hair treated general formulation(control) and the hair applying special formulation including 3 kinds of extracts, tensile distance and energy of the latter are larger than control on average. The shine and color appearance were also increased after using shampoo including natural extracts(shine : 10.9%, color appearance: 24.12%). We observed the enhancement of hair growth activity in the DP6 and C3H10T1 cell. Especially black bean extracts had the most powerful effect in the dermal papillar cell proliferation. Conclusion : These experiments suggest that extracts of Glycine max Merr. (black bean), Triticum aestivum L. (wheat) and Oryza sativa L. (rice bran) stimulate the hair growth activity and can improve physical activities of aged hair. Shampoo product, which contains 3 kinds of natural extracts, would be used for the treatment for aged hair.

• Korean Journal of Microbiology
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• v.1 no.1
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• pp.38-44
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• 1963

According to the experiment on pure-isolation and the related contaminants of Chlorella, the phenomena of the ecological distributions of Chlorella in Korea have been manifested in several areas and also the aim that in going to do culture, biological and physiological study of Chlorella is carried out. Contaminants very oftenly occupied on the colony of the strains taken in order to fulfil pure-isolation of Chlorella, but in accordance with being piled up the minute research on this subject, I can obtain the desirable results as follows: 1. For the pure-isolation, the duration chose the time from May to September 1957 so that may easily isolate from contaminant water with utilizing the antibiotic substances. 2. To take long time, 36-48 hours until growth of nascent through the non-sporulated, it originates from the difference of the cultured media. In addition to the above mention, the mechanism of growth until nascent through the sporulated must not always require the ligh. However the supply of metabolic energy depend upon its nutritional conditions per phase. 3. The culture of Chlorella should be based on the lower culturing except adding especial conditions such as reagent concentration of media, artifical shake of media and other facts due to the natural conditions. And also these strains grew not only in distilled water but 2% NaCl solution without any abnormality in cell it self. I, therefore, guess it is possible to culture in sea-water under phasic environment. 4. In the experiment of ammonia detection, it is caused by the sampling surroundings to contain the minute quantity of ammonia in strain No. M 918; that is the place to be plenty of Carbohydrate on behalf of protein. 5. To compare the absorption curve of chlorophyll of higher plant with that of Chlorella, the absorption zone made mostly the Same ones each other but a little absorption grade dose not clearly appear. The colony which formed giant type grows with intensive colour and green band on surrounding of the colony and after that it was changed into all the green colour and developed up to end. 6. At first phase for a week, the development of Chlorella suspends the normal condition as in vivo but after a few days, the colour of chlorophyll gradually changed into blue-yellow which secrete the mucous substances on the agar media. The cell was flew out the contained substances itself on leaving the cell wall only, or the various micro-organism diffused on the outer-region of the cell.