• 생명과학회지
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• 제27권9호
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• pp.1040-1046
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• 2017

우리는 처음으로 쌍별귀뚜라미 소화기관에서 6종류의 미생물을 분리하고 특성을 규명하였다. 이들은 16S rDNA을 기준으로 분류한 결과 4종류(Staphylococcus, Bacillus, Citrobacter, Proteus)에 속하였다. 분리된 6종류의 미생물은 공통적으로 ampicillin에 저항성을 보이지만 kanamycin 저항성은 보이지 않았다. 이들을 Gram염색하여 미생물의 형태적 특징을 확인하였다. Gram-positive한 rod-shaped GL2와 round-shaped GL4는 다른 분리 균 보다 많은 양의 세포외분비물을 만들었다, 이들을 MALDI-TOF-MS spectral analysis결과 87-kDa collagenase, 56-kDa & 200-kDa hypothetical protein이였다. 새롭게 분리된 6종류의 미생물은 귀뚜라미의 생리에 미치는 영향과 이들의 생물공학적 혹은 해충 방제에 이용될 수 있는 연구가 기대된다.

• 한국농림기상학회지
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• 제1권1호
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• pp.36-40
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• 1999

A new method was developed to measure underground water level with high reliability. The principle of new method was to detect a change of a buoyant force according to change in water level of underground water measured by the use of a straingage load cell. Field test of the instrument was carried out in Cheju Island. The results were as follows; 1) The present study provided a possibility to develop a new underground water level meter. 2) This new instrument accomplished high reliability at field test in Cheju Island. 3) There is possibility of development of water level meter which measure various range of water level to detect a weight change of a buoyant forcd.

• KSBB Journal
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• 제8권1호
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• pp.89-94
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• 1993

Thc effect of light and phylohormonc on the belalaln synthesis was tested using the suspension culture of a rod(bclalaln produulng) cell line from Phytolacca esculenta V. Houtte. Betalain synthesis of rod-cell 1ine was strongly dependent on the irradiation of blue light, but induced by hormone, IAA and/or kinetin, in dark conditions. In a light condition, however, 2 mg/l of IAA increased the betalain content about 30% (per gram fresh weight), whereas more than 0.5mg/l of kinetin remarkably decreased. The hairy root derived from the same plant was also observed for the blue light-dependent pigmentation in the root-tips. When the hairy root grown in dark was transferred to the light condition, the accumulation of betalain was initiated after 12hours. Such pigmentation was completely inhabited by addition of a protein synthesis inhibitor.

• Korean Chemical Engineering Research
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• 제50권1호
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• pp.162-166
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• 2012

본 연구에서는 전해증착법과 열처리를 통하여 ITO 투명전극 위에 고밀도의 ZnO 막대구조를 형성하는 방법을 조사하였다. 증착과정에서 $Zn(OH)_2$와 ZnO가 함께 형성되는 것을 고려할 때 전기화학적 ZnO 증착효율은 33% 이하를 나타내었다. $500^{\circ}C$ 열처리 후 ZnO는 (002)를 선택적으로 갖는 결정구조를 형성하며, 나노막대 구조의 성장속도는 0.986 ${\mu}m/hr$로 측정되었다. 그리고 전기화학적으로 제조한 ZnO 막대를 염료감응 태양전지의 전극으로 사용시 측정된 전지효율은 0.21%로서 태양전지용 전극으로서의 가능성을 확인하였다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1995년도 추계학술발표회논문집(2)
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• pp.680-686
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• 1995

It has been known that water-side corrosion of fuel rods in nuclear reactor is accompanied with the loss of metallic wall thickness and pickup of hydrogen. This corrosion is one of the important limiting factors ill the operating life of fuel rods. In connection with the fuel cladding corrosion, a device to measure the water-side oxide layer thickness by means of the eddy-current method without destructing the fuel rod was developed by KAERI. The device was installed on the multi-function testing bench in the nondestructive test hot-cell and its calibration was carried out successfully for the standard rod attached with plastic thin films whose thicknesses are predetermined. It shows good precision within about 10% error. And a PWR fuel rod, one of the J-44 assembly discharged from Kori nuclear power plant Unit-2, has been selected for oxide layer thickness measurements. With the result of data analysis, it appeared that the oxide layer thicknesses of Zircaloy cladding vary with the length of the fuel rod, and their thicknesses were compared with those of the destructive test results to confirm the real thicknesses.

• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3301-3312
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• 2023

This study incorporates a high-fidelity transient analysis solver based on multigroup CMFD in the MOC code STREAM. Transport modeling with heterogeneous geometries of the reactor core increases computational cost in terms of memory and time, whereas the multigroup CMFD reduces the computational cost. The reactor condition does not change at every time step, which is a vital point for the utilization of CMFD. CMFD correction factors are updated from the transport solution whenever the reactor core condition changes, and the simulation continues until the end. The transport solution is adjusted once CMFD achieves the solution. The flux-weighted method is used for rod decusping to update the partially inserted control rod cell material, which maintains the solution's stability. A smaller time-step size is needed to obtain an accurate solution, which increases the computational cost. The adaptive step-size control algorithm is robust for controlling the time step size. This algorithm is based on local errors and has the potential capability to accept or reject the solution. Several numerical problems are selected to analyze the performance and numerical accuracy of parallel computing, rod decusping, and adaptive time step control. Lastly, a typical pressurized LWR was chosen to study the rod-ejection accident.

• Applied Microscopy
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• 제11권1호
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• pp.59-65
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• 1981

활동기와 동면기중 Rana dybowoskii Guenther의 뇌하수체 전엽을 전자현미경적으로 비교한 결과 7 가지의 cell type를 구분할 수 있었으며 이 cell type 중 type 5 에서 많은 차이를 관찰할 수 있었다. Cell type 1 : 분비 과립의 크기는 $375{\sim}687m{\mu}$ 정도였고 모양은 완전 구형이었다. Cell type 2 : 분비과립의 크기는 $250{\sim}437m{\mu}$ 정도였으나 모양은 비교적 다양하였다. Cell type 3 : 분비과립의 크기는 $125{\sim}187m{\mu}$ 정도고 모양은 난형내지 rod 형이었다. Cell type 4 : electron density 가 가장 낮으며 과립의 밀도는 제일 높았다. 모양은 매우 다양하였으며 가끔 대과립도 관찰되었다. 분리과립의 크기는 대개 $210{\sim}420m{\mu}$ 정도이다. Cell type 5 : electron density는 cell type 4 와 유사하나 분비과립의 윤곽은 cell type 4 보다 훨씬 뚜렷하였다. 과립의 밀도는 cell type 4 보다 낮으며 모양은 cell type 4와 비슷하나 rod 형이 많다. 분비과립의 크기는 $200{\sim}863m{\mu}$이다. Cell type 6 : type 2와 비슷하나 cytoplasm 의 electron density가 매우 낮은 light cell 이다. 분비 과립의 크기는 대개 $232{\sim}316m{\mu}$이다. Cell type 7 : 어떤 분비 과립도 함유하고 있지 않은 미분화된 세포이다. 활동기와 동면기의 차이점은 type 5 에서 관찰 할 수 있었다. 즉 활동기에는 분바과립이 매우 발달하였으나 동면기에는 매우 감소되며 cytoplasm에는 크고 작은 vacuole로 가득 차있다.

• 미생물학회지
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• 제28권1호
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• pp.83-89
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• 1990

토양으로부터 세포의 adcnosinedeaminase를 생산하는 두종의 방선균 J-845S주와 J-326TK 주름 분리하여 각각 Streptomycs sp. J-845S와 Nocardioides sp. J326TK로 동정하였다. Streptomyces sp. J-845S는 그람염색 양성, 비항산성균으로 기균사의 흰색계열의 간상형의 비운동성의 포자를 형성하였으며, 포자의 표면은 평할하였고 나선상의 포자연쇄를 형성하였다. 균사체의 분자는 양호하였다. 세포벽 구성성분을 분석한 결과 LL-diaminopimelic acid를 함유하는 cell wall type I 이었으며, phospholipid type II였다. Nocardioides sp. J-326TK는 그람염색반응 양성, 항산성염색반응 음성이었으며, 균사체는 불규칙한 간상 또는 구사으이 절편으로 분절되었다. 기균사의 분자는 그다지 인정되지 않았으며, 포자형태의 긴 elements의 표면은 평할하였다. 세포벽 구성성분을 검토한 결과 cell wall type I과 phospholipid type I으로나타났다.

• 한국기계가공학회지
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• 제5권2호
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• pp.56-64
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• 2006

Rapid progress in many branches of technology has led to a demand on new materials such as high strength light weight alloys, powdered alloys and composite materials. The hydrostatic extrusion is essentially a method of extruding a clad rod through a die. In order to investigate the effect of the process conditions such as friction heat, deformation and clad thickness on the clad extrusion process, viscoplastic finite element simulations were conducted. A specific model for theoretical analysis used in this study is The single scalar variable version of Hart's model. An experiment also has been carried out using 1.5MN hydrostatic extruder with variable speed ram, LVDT and load cell for comparison. It is found that the hydrostatic extrusion pressure considering the effect of heat dissipation in this theoretical work was closer to the experimental pressure than the isothermal hydrostatic extrusion pressure.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.731-736
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• 2000

An optimal design method is adopted for a spacer grid in nuclear power plant. It is made of punched sheet metal process, functioning as springs and dimples supporting fuel rods. For stress analysis of the assembled fuel rod support, a typical cell out of the repeated pattern in the assembly is modeled using 4-node shell elements. A commercial code, ABAQUS, is used for detailed analysis of contacting phenomena with friction. For the optimization, design varibles are taken from geometric parameters representing the shape of the bent leaf spring part and mating contact region with fuel rod. Objective function is considered in relation to mechanical functions and durability. Maximum yon Mises stress is considered in relation to constrained contact stress.