• BMB Reports
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• 제33권6호
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• pp.506-509
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• 2000

To obtain Cytochrome $c_3$ labeled with a stable isotope, the conditions of cultivation and the composition of medium for DvMF were examined. The growth of DvMF was steady and reproducible under purging with $N_2$ and under pH control. DvMF was able to go on a defined medium without natural products. The composition of the medium containing a small amount of $NH_4Cl$ as sole nitrogen source was established. Then, uniformly $^{15}N-labeled$ Cytochrome $c_3$ was obtained during the culture of DvMF in a defined medium with $^{15}NH_4Cl$; it was confirmed by $^{1}H-^{15}N$ HMQC.

• 한국환경과학회지
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• 제23권5호
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• pp.895-902
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• 2014

Bacterial cellulose (BC) has played important role as new functional material for food industry and industrial products based on its unique properties. The interest in BC from static cultures has increased steadily in recent years because of its potential for use in medicine and cosmetics. In this study, we investigated culture condition for BC production by Acetobacter sp. F15 in static culture. The strain F15, which was isolated from decayed fruit, was selected on the basis of BC thickness. The optimal medium compositions for BC production were glucose 7%, soytone 12%, $K_2HPO_4$ 0.2%, $NaH_2PO_4{\cdot}_2H_2O$ 0.2%, lactic acid 0.05% and ethanol 0.3%, respectively. The strain F15 was able to produce BC at $26^{\circ}C-36^{\circ}C$ with a maximum at $32^{\circ}C$. BC production occurred at pH 4.5-8 with a maximum at pH 6.5. Under these conditions, a maximum BC thickness of 12.15 mm was achieved after 9 days of cultivation; this value was about 2.3-fold higher than the thickness in basic medium. Scanning electron micrographs showed that BC from the optimal medium was more compact than plant cellulose and was reticulated structure consisting of ultrafine cellulose fibrils. BC from the optimal medium was found to be of cellulose type I, the same as typical native cellulose.

• 한국물환경학회지
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• 제23권5호
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• pp.712-722
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• 2007

This study screened three natural ores (iron, mangenase, and zinc), two types of slags, and two elemental metals (elemental iron and zinc) to evaluate transformation characteristics of CAH mixtures [e.g. Carbontetrachloride (CT), 1,1,1-Trichloroethane (1,1,1-TCA), and Perchloroethene (PCE)]. To select an effective metal medium to treat the CAH mixtures, we measured transformation capacities (CAH mass ultimately transformed/mass of metal added) and the degree of dechlorination. We also considered economical efficiency of the metal media by comparing the value, CAH mass ultimately transformed divided by the price of metal medium added. A simplified mathematical model adapting CAH transformation capacity, first-order transformation kinetics, and available mass of metal transforming CAH was developed and used for estimating CAH transformation rate coefficient and longevity of the metal medium. CAH transformation capacity for elemental iron and elemental zinc were 4258~7129 and $4215{\sim}6330{\mu}g\;CAH\;transformed/g$ metal added, respectively, which are a factor of 80~200 higher than slags and natural ores. They also showed a factor of 1.1 to 2.2 greater degree of dechlorination than the others. Among natural ores and slags, Zinc ore showed the highest transformation capacity, $47{\sim}53{\mu}g\;CAH\;transformed/g$ metal added. Although zinc ore have smaller transformation capacity than elemental metals, economical efficiency of zinc ore is a factor of 10~20 greater than elemental metals tested. Consequently, zinc ore would be more economical medium than the others tested in this study. We estimated the pseudo first-order transformation rate of zinc ore was in the order of CT > 1,1,1-TCA > PCE.

• Journal of Plant Biotechnology
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• 제31권1호
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• pp.25-29
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• 2004

돌나물 (Sedum samentosum)의 기내 식물체 재분화 체계를 확립하기 위하여, 생장조절물질을 다르게 조합한MS배지에 잎절편을 치상한 후,캘러스 유기 및 식물체 분야에 미치는 생장조절물질의 영향을 조사하였다. 캘러스 유기는 3.0mg/L 2,4-D와 1.0mg/L BA첨가 배지에서 가장 높은 캘러스 유기율을 보였으나, NAA와 BA 혼합첨가 배지에서는 캘러스 형성율이 0∼3%이하로 극히 낮았다. 식물체 분화는 NAA 단독첨가 배지에서는 전혀 분화되지 않았으며,0.2mg/L NAA와 3.0mg/L BA첨가배지에서 가장 양호하였다. 캘러스를 식물체 분화배지에 계대배양 후 50일까지는 신초수 증가와 함께 (17.2개/캘러스),식물체의 기형이나 잎비대 현상도 적어 식물체 분화배지로 가장 적합하였다. 분화 식물체는 생장조절물질을 첨가하지 않은 MS기본배지로 계대배양하였을 때 발근 및 생육이 양호하였다.

• 한국안전학회지
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• 제32권4호
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• pp.122-128
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• 2017

Recently, accidents such as human accidents are increasing rapidly due to natural disasters and changes in social conditions due to abnormal weather. As a result, damage has been causing massive damage unlike the past. In the case of small and medium enterprises excluding financial institutions and big company, there is no system for prevention and restoration for stable operation from various risks such as human and natural disasters. As the current disaster continues, public and private companies have raised the need for BCM, and with the introduction of the ISO22301 certification system, the company has been establishing and operating Enterprise Disaster Management Standards in the Ministry of Public Safety and Security since 2007. However, in most SMEs, it is hard to bear the input of internal labor and investment cost, and there is a lack of personnel with expertise to conduct BCM diagnosis. Therefore, in this paper, we will study the diagnosis level of enterprise continuity plan which is commonly used in Korea and abroad. Based on this, we will study the BCM system diagnosis method which can be applied to small and medium enterprises in Korea efficiently.

• Journal of Plant Biotechnology
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• 제30권3호
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• pp.245-249
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• 2003

This study was carried out to establish a regeneration system from leaf explant of purple sweetpotato(Ipomoea batatas L.) The optimal concentrations of plant growth regulators for callus induction and shoot formation were determined. The optimal combination for callus formation was 1$\mu$M 2,4-D 5$\mu$M BM, and highest yield of embryogenic calli were observed on Murashige and Skoog basal medium containing 0.5$\mu$M 2,4-D under light condition after 4weeks of culture. Embryogenec callus was subcultured on medium supplemented with 5$\mu$M ABA for 4 days. Subsequently, regeneration of adventitious shoots occurred when these embryogenic calli were transferred onto medium with 3∼6$\mu$M gibberellic acid. Regenerated shoots were developed into normal plantlets.

• 자연과학논문집
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• 제8권2호
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• pp.147-152
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• 1996

딸기의 3품종을 엽과 엽병으로 배양한 결과 2,4-D + BA 처리에서는 치밀한 캘러스가 유기되었고 이 캘러스로부터 다수의 신초가 분화되었으며 NAA + BA 처리에서는 부숴지기 쉬운 캘러스가 유기되었다. '수홍' 엽조직을 NAA나 2,4-D가 첨가된 배지에서 8개월간 배양하면 212번 primer에서 생산된 RAPD band가 모본 band와는 상이하게 나타났다. '보교'와 '여봉'의 엽에서 유기된 캘러스를 2,4-D가 첨가된 액체배지에 계대배양회수를 달리하여 배양하였을 때 12회 계대배양에서 모본과 상이한 RAPD band가 출현되었다.

• 자연과학논문집
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• 제12권1호
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• pp.69-79
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• 2002

PDA-calcium phosphate 평판배지를 이용하여 인산가용화활성을 가진 850종의 세균을 분리한 후 인광석에 대한 인산가용활성이 가장 강한 HS-2 균주를 선발하였다. 선정 균주의 형태학적, 배양학적 및 생리생화학적 특성 등을 조사한 결과 Azotobacter sp. HS-2로 동정되었고, 이 균주을 인광석을 0.1%함유한 Potato dextrose Broth배지 (pH 6.0)에 접종하여 $30^{\circ}C$에서 5일 배양했을 때 인광석이 가장 많이 분해되었고 0.5M의 수산을 첨가했을 때 분해율이 약 50% 증가되었다.

• 한국석유지질학회지
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• 제1권1호
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• pp.47-52
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• 1993

지진파의 전파속도와 감쇠정도가 불균질한 매질에서 2차원 지진파 단면자료에 대한 주파수-파수 영역에서의 구조보정 방법 및 그 결과를 제시한다. 파동전파의 감쇠효과를 포함시키기 위해 일반화된 주파수-파수 구조보정 방법을 개선하여 파동장의 상향 및 하향 외삽연산자에 복소수 전파속도를 사용한다. 이 복소수 전파속도의 허수 부분은 지진파 감쇠 척도인 Q 값을 포함하도록 한다. 불균질한 전파속도와 비탄성을 가진 매질 속에서의 전파방정식의 해를 얻기 위해, 불균질한 매질자체를 일정한 전파속도와 비탄성을 갖는 평균적 매질과 가상적 파동원의 불균질한 분포로 규합된 등가의 시스템으로 취급한다. 가상적 파동원은 전파속도와 매질비탄성의 불균질 정도에 따라 그 세기가 좌우된다. 이 방법에 의해 수 개의 구조 모델에 대해 수치적으로 계산된 결과는 기존의 일반화된 파수-주파수 구조 보정 방법에 의한 것보다 더욱 선명한 단면 영상을 보여주며 파의 비탄성에 의해 불명확하게된 영상신호가 복원된다. 이 방법은 석유나 천연가스가 부존된 구조 또는 파쇄대가 존재하는 지역에서 획득된 자료를 구조보정하는데 유용하게 쓰일 것이다.

• 한국해양공학회지
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• 제31권3호
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• pp.196-201
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• 2017

A cylindrical structure has a very long period of heave and pitch motion response in ocean waves. To obtain the dynamic stability of a cylindrical structure, it is necessary to obtain the suitable metacentric height (GM). However, in a structure with sufficient metacentric height, Mathieu instability can occur if the natural frequency of the heave motion is double the natural frequency of the roll and pitch motion. This study carried out numerical calculations and experiments for vertical-axis wind turbines with cylindrical floaters, which had three different centers of gravity. In the regular wave experiment, the divergence of the structure motion without yaw was observed when the natural frequency of the heave motion was double the natural frequency of the roll and pitch motion. In the irregular wave experiment, the motion spectra of the structures with the different centers of gravity were compared, and one was very high when the natural frequency of the heave motion was double the natural frequency of the roll and pitch motion.