• Journal of Microbiology and Biotechnology
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• 제14권5호
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• pp.1038-1042
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• 2004

The photoelectric responses of a biodevice consisting of chlorophyll $\alpha$ Langmuir-Blodgett film were investigated. Chlorophyll $\alpha$ Langmuir-Blodgett films were deposited onto ITO and Au coated glass. To confirm film formation, surface analysis of chlorophyll $\alpha$ Langmuir-Blodgett film was carried out by measurement using atomic force microscopy. The metal/insulator/metal structured biodevice was constructed by depositing aluminum onto the chlorophyll $\alpha$ Langmuir-Blodgett film surface. To investigate the photoelectric response, the current-voltage characteristic was measured by the conducting metal tip. The photoswitching function and transient photovoltage characteristics of the proposed device were measured by irradiation with Ar ion laser and $N_2$ pulse laser, respectively. This research suggested that the proposed biodevice consisting of chlorophyll $\alpha$ could be applied to the molecular scale biosensor and/or bioelectronic device.

• Applied Microscopy
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• 제31권2호
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• pp.199-206
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• 2001

완두 자엽세포에 대한 저장단백질 과립의 발달은 단백질 저장 액포의 가장자리에 축적된 단백질의 fragmentation에 의해서 이루어지는 것으로 알려져 왔다. 그러나 최근 이 외에도 terminal dilation, transformation, denovo development등의 독립적인 과정이 각각 다른 시기에 관찰되므로서 단백과립의 발달은 이러한 여러 과정이 모두 나타나는 복합과정임이 알려졌다. 이러한 과정과는 별도로 종자발달의 이른시기에 소포체 내강에 축적되는 저장단백질과 여기서 발달하는 단백과립에 대하여 규명하고자 발달중인 종자의 자엽으로부터 단일 세포를 얻어서 면역세포 화학적 반응을 실시하였다. 그 결과 종자발달의 이른 시기에는 legumin이, 중간시기 이후 에는 vicilin이 축적되므로서 단백질이 축적된 소포체가 단백과립으로 발달하는 것으로 나타났다 소포체 내강에 존재하는 단백질인 $\alpha-Tip$은 비교적 늦은시기에, toneplast membrane protein인 PPase는 이른시기에 각각 면역 세포화학적 반응이 관찰되었다.

• 한국약용작물학회지
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• 제11권4호
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• pp.316-320
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• 2003

A protocol is described for rapid multiplication of Zanthoxylum piperitum DC. (Rutaceae), an important aromatic and medicinal plant, through shoot-tip explant cultures. Murashige and Skoog (MS) medium supplemented with various concentrations of N-6-benzyladenine (BA), N-6-benzylaminopurine (BAP) and thidiazuron (TDZ), in single or in combination with ${\alpha}-naphthaleneacetic$ acid (NAA), was used to determine the rate of shoot proliferation. N-6-benzyladenine (BA) used at 0.5mg/l, was the most effective in initiating multiple shoot proliferation at the rate of 23 microshoots per shoot-tip explants after 40 days of culture. Shoot multiplication increased 1.2-fold in each successive subculture. Induction of rooting (98%) was achieved by transferring the shoots to the same basal medium containing 2 mg/l indole-3-butyric acid (IBA). Plantlets went through a hardening phase in a controlled growth chamber, prior to in vivo transfer. These results represented that possible application for the mass production of plantlets through in vitro culture system of Zanthoxylum piperitum DC.

• 대한기계학회논문집
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• 제8권5호
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• pp.401-407
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• 1984

본 연구에서는 구속공구 및 정상공구에 대하여 공구경사면의 전단응력과 수직 응력을 해석하고 칩 유동시의 마찰계수분포를 검토하였다.

• 대한기계학회논문집
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• 제15권3호
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• pp.963-969
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• 1991

본 연구에서는 누설와류는 유동에 영향을 미치며 에너지 손실로 된다. 누설 와류에 의한 손실은 다른 원인에 의한 손실에 비교하여 그 비중이 크다. 따라서 누 설와류 특성을 이해하기 위해 설계영각(.alpha.=10.7˚)에서 절현비를 t/C=0.90와 2.71로 바꾸고, 또 절현비가 설계절현비 t/C=0.90일 경우에 영각을 설계 영각 .alpha.=10.7˚와 실 속점의 영각 .alpha.=18.9˚사이에서 바꾸어 회전익 후방의 회전유동장을 측정하여 누설와 류의 거동을 연구하였다.

• 산업기술연구
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• 제21권B호
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• pp.341-348
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• 2001

The effect of initial ${\alpha}^{\prime}$ in STS 304 Stainless Steel on fatigue resistance, and fatigue crack propagation behavior was studied with using C-T specimens. Higher ${\Delta}K_{th}$ was observed in the specimens with the content of 0% initial ${\alpha}^{\prime}$ than in the contents of 2% and 33% initial ${\alpha}^{\prime}$. The difference of da/dN at the same level of ${\Delta}K$ was distinctive in low and intermediate level of ${\Delta}K$ however became less different as the level of ${\Delta}K$ increased. It is because the formation of strain induced martensite occurred readily in lower ${\alpha}^{\prime}$ at the vicinity of the fatigue crack tip, which causes compressive residual stresses resulting in the enhancement of crack closure. In general fatigue cracks propagated transgranular mode and many segments of ridges were observed on the fracture surfaces. At the higher contents of initial ${\alpha}^{\prime}$ appeared the smaller size of ridge segments. Slips in austenite were blocked more frequently by the martensite colonies formed in austenite.