• Journal of Mechanical Science and Technology
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• 제16권7호
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• pp.959-965
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• 2002

Effective hydraulic conductivity of a statistically anisotropic heterogeneous medium is obtained for steady two-dimensional flows employing stochastic analysis. Flow equations are solved up to second order and the effective conductivity is obtained in a semi-analytic form depending only on the spatial correlation function and the anisotropy ratio of the hydraulic conductivity field, hence becoming a true intrinsic property independent of the flow field. Results are obtained using a statistically anisotropic Gaussian correlation function where the anisotropy is defined as the ratio of integral scales normal and parallel to the mean flow direction. Second order results indicate that the effective conductivity of an anisotropic medium is greater than that of an isotropic one when the anisotropy ratio is less than one and vice versa. It is also found that the effective conductivity has upper and lower bounds of the arithmetic and the harmonic mean conductivities.

• Journal of Plant Biotechnology
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• 제37권4호
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• pp.494-504
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• 2010

본 연구에서는 고추의 소포자 배양 시 전처리 후 배지의 교환 여부, 배양 후 새 배지의 첨가 및 2층배지 사용시 하층고체배지의 양이 배의 생산에 미치는 영향을 조사하였다. 고온 전처리 후 배양배지를 첨가하여 배양하는 것보다 사용한 전처리 배지를 새 배양 배지로 교환하여 배양 하는 것이 배의 생산에 효과적 이었으며, 고온전처리 기간은 1일이나 2일에 비해 3일이 효과적 이었다. 배양 후 새 배지의 첨가는 약전처리 시에는 효과가 없었으나 소포자 전처리 시에는 배의 유기와 발달 모두 크게 향상되었다. 새 배지의 첨가 시기는 배양 4일 후가, 첨가 횟수는 1회가 배의 생산에 가장 효과적이었다. 한편 2층배지 사용 시 첨가하는 새 배지의 양은 1.5 ml이 효과적이었으며 이보다 많은 양을 첨가하는 경우 배의 발생과 발달 모두 저하되었다. 액체배지 사용 시에 비해 2층배지 사용 시 배의 발달이 좋았다. 또 2층배지 사용 시 하층고체배지의 양이 3 ml 일 때 보다는 5 ml이나 7 ml일 때 배의 발생은 감소하였으나 배의 질이 향상되었다. 이와 같은 결과들은 고추에서 다수의 정상자엽배를 생산 할 수 있는 소포자 배양시스템을 확립하는데 중요한 기초자료가 될 것이다.

• 화훼연구
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• 제17권2호
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• pp.114-120
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• 2009

Pteris cretica 'Wilsonii'의 대량생산에 적합한 배양환경을 구명하기 위하여 연구를 수행하였다. 포자는 7주 안에 모두 발아하였다. Knop과 Hyponex배지에서 전엽체 증식이 왕성하였지만, 전엽체의 생육에는 Hyponex 배지가 더 유용하였다. MS배지에서는 전엽체가 괴사하였으며, 질소급원과 sucrose의 농도를 조절한 경우에도 sucrose 무첨가구를 제외한 모든 첨가구에서 전엽체가 괴사하였다. Sucrose 1%와 agar 0.6%를 첨가한 Hyponex배지가 전엽체의 증식과 생육에 가장 적합한 것으로 나타났다. 접종방법을 달리한 결과, Hyponex배지에서는 다져서 접종하는 전엽체의 증식 및 생육에 효과적이었지만, MS배지에서는 전엽체의 군집을 4등 분하여 접종한 처리구에서 전엽체의 증식 및 생육이 우수하였다. 고체배지에서 배양하는 것이 액체배지에서 배양하는 것보다 효과적이었다. 액체배양은 전엽체의 괴사를 유도하였다. 액체진탕배양한 전엽체는 생육은 우수하였으나 고체배양한 전엽체에 비하여 증식이 억제되었다.

• 대한기계학회논문집B
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• 제20권9호
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• pp.3015-3029
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• 1996

The notion of effective transport property of a heterogeneous medium implies that the medium is large enough that the ergodic theorem holds and local fluctuation of the property can be neglected. In case that the medium is not large enough compared to its characteristic microstructure length scale, the effective property fluctuates and differs from the value of the medium being large enough. As a representative transport phenomenon, diffusion was considered and the fluctuation of varying effective diffusion property, diffusion coarseness $C_k$, was defined as a quantifying parameter. Scaled effective diffusion property, $^*$>/k$_1$ and $C_k$ were computed for the two phase random media consisting of matrix of diffusion coefficient k$_1$ and spheres of diffusion coefficient k$_2$. Numerical simulations were performed by use of the so-called first passage time technique and data were collected for existing microstructure models of hard spheres(HS), overlapping spheres(OS) and penetrable concentric shells(PCS).

• 한국축산식품학회지
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• 제28권1호
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• pp.105-108
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• 2008

The cell growth and antioxidant activity of Bacillus polyfermenticus SCD were studied in tryptic soy broth (TSB) medium and whey protein concentrate (WPC)-based medium. Overall, higher lactose contents in WPC-35 medium (up to 2.0%), and longer culture times correlated with greater cell viability. In WPC-35 medium with 1.5% and 2.0% lactose, the cell growth of B. polyfermenticus SCD was similar to growth in TSB medium. The 1,1-diphenyl-2-picyrylhydrazyl (DPPH) radical scavenging activity of culture supernatant of B. polyfermenticus SCD in WPC-35 medium was measured to assess antioxidant activity. The antioxidant activity increased up to 32 hr of culture, reaching a maximum of 75.57% DPPH radical scavenging activity. The antioxidant activity seemed to follow the typical kinetics of primary metabolite synthesis. The antioxidant activity of B. polyfermenticus SCD supernatant in WPC-35 medium was more effective and stable than supernatant from TSB medium. These results suggest that WPC-35 medium is effective for the production of antioxidant by B. polyfermenticus SCD.

• 한국약용작물학회지
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• 제14권5호
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• pp.293-298
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• 2006

Optimum culture conditions for high frequency plant regeneration from leaf explants of Kalanchoe daigremontiana Hamet &Perrier were established. Shoot regeneration was achieved from leaf explant cultures using MS medium supplemented with indole-3-acetic acid (IAA) and thidiazuron (TDZ) or benzyladenine (BA). Percent regeneration was influenced by plant growth regulators and source of explants. MS medium supplemented with TDZ (1.0 mg/l) and IAA (0.4 mg/l) was the most effective, providing shoot regeneration for 76.7 % of ex vitro leaf explants associated with a high number of shoots per explant (9.5 mean shoots per explant), whereas 100% shoot regeneration associated with 12.4 shoots per explant occurred from in vitro leaf explants on the same medium. Clusters of shoots were multiplied and elongated on MS medium containing several concentrations of BA. MS medium supplemented with 0.25 mg/l BA was proved as the most effective shoot elongation medium. Elongated shoots (2-3 cm) were rooted at 100% on half-strength MS medium. Rooted plantlets were then transferred to potting soil. Regenerated plants were established in the soil with 90% success.

• 공업화학
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• 제19권6호
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• pp.609-616
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• 2008

본 연구는 크기가 다른 두 종류의 입자를 가진 비(非)콜로이드성 현탁액의 평균 침강 속도를 예측하는 수치적 방법을 제공한다. 이 방법은 무수히 많은 입자들이 유체에 불규칙적으로 분포된 현탁액 시스템의 유체 속도, 온도 등의 물리량을 앙상블 평균의 개념을 사용해서 표현하는 유효 매체 이론에 기초한다. 본 연구에서는 Acrivos와 Chang[1]이 단일(單一) 입도 현탁액에 대해 제안한 모델을 이중(二重) 입도 현탁액에 응용한다. 구체적으로 방사 분포 함수(radial distribution function)에 대한 계산과 stream function을 이용하여 침강 속도를 계산하고 그 결과를 Davis와 Birdsell[2]과 Cheung 등[3]의 실험 결과와 비교하였다. 그 결과 본 연구의 모델에 의한 예측이 실험 결과와 일치하는 것으로 나타났다.

• Journal of Plant Biotechnology
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• 제3권3호
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• pp.141-144
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• 2001

To enhance the shoot induction efficiency from nodal stem of yooza, the culture conditions such as basal medium, carbohydrate source, solidifying agent and the optimum concentration of plant growth regulators for shoot induction were investigated. The nodal explants were cultured better on MS medium than on MT, SH, B5 or W media in considering of shoot induction rate and mean shoot length. Solidifying agent in medium was better with 0.8% agar than with 0.3% agar, 1.2% agarose or 0.2% gelrite. Carbohydrate source in shoot induction medium was efficient with 30 g/L sucrose. The optimum concentrations of plant growth regulators were determined that 0.1 mg/L NAA as auxin was effective on the shoot induction, and 1.0 mg/L BAP as cytokinin induced multiple shoots efficiently. Shoot induction was the most effective on MS medium supplemented with 4 mg/L $GA_3$ in yooza.

• 한국자원식물학회지
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• 제11권1호
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• pp.1-8
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• 1998

This study was conducted to establish mass propagation system from the axillary bud culture of chrysanthemum zawadskii H. which was used as material of medicinal plants. Shoot egeneration was better on MS medium with NAA and BA. The optimum concentraions of growth regulator for shoot regeneration differed depending on accessionsof C. Zawadskii. Shoot regeneration in Keungucheolcho was better on MS Medium with NAA 0.01mg/1 and BA 0.1mg/1 while Hyangrobonggucheocho was better with NAA 0.1mg/1and BA 0.3mg/1. Addition of NAA into medium was effective for induction of root from shoots regenerated. Shoot multiplcation was more effective when 10mg/1 spermine was added into medium than when other polyamines were treated ino medium . Randomly and specifically amplified polymorphic DAC banding patterns based on polymerase chain reaction (PCR) analysis were used to assess the genetic variation of plants regenerated from in vitro culture.

• 한국약용작물학회지
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• 제20권3호
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• pp.190-194
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• 2012

Shoot tips of chinese yam (Dioscorea opposita Thunb.) were cultured on MS medium containing 0.5 mg/L BA to produce micro-tubers in vitro. To stimulate the formation of shoots and micro-tubers, and produce large micro-tubers, the sections of micro-tubers were cultured on MS media with BA and IAA. The shoot multiplication, and the micro-tuber formation and growth were very effective on the media containing 2.0 mg/L BA and 0.5~1.0 mg/L IAA. Sucrose added to MS medium with 2.0 mg/L BA and 0.5 mg/L IAA to stimulate more micro-tuber growth. The medium added 50 g/L sucrose was very effective in the increase of plant fresh weight and micro-tuber growth. After 4 weeks' culture of micro-tuber sections on the medium with 2.0 mg/L BA, 0.5 mg/L IAA and 50 g/L sucrose, the liquid media were added into the same vessels. The micro-tuber growth was stimulated remarkably by the addition of liquid medium. The addition of 25 $m{\ell}$ liquid medium containing 10 g/L activated charcoal, 3x MS salts and 250 g/L sucrose was the most effective in micro-tuber growth.