• 한국수산과학회지
• /
• 제36권6호
• /
• pp.563-567
• /
• 2003

Various bacterial strains were isolated from rice field ditch water, and their seaweed degrading activities were investigated. They were incubated in a liquid medium of sea tangle (Laminaria iaponica) and sea mustard (Undaria pinnatifida) powder for 3 weeks. Ratios of reduced sugar to total sugar of the liquid medium were measured once a week. Ratios of reduced sugar to total sugar of 27A311, 27C221 27A111 and 27B121 strains were highest. Accordingly, these four strains were incubated in 3 different liquid media of sodium alginate, sea tangle powder, and sea mustard powder for 3 or 4 weeks. The ratios of reduced sugar to total sugar and cell growth were measured once a week. Cell growth was higher in 27A111 and 27C221. Ratios of reduced sugar to total sugar was higher for 27C221 in the liquid mediums with sodium alginate and sea mustard powder, and for 27A111 in the liquid medium with sea tangle powder.

• Archives of Pharmacal Research
• /
• 제20권3호
• /
• pp.206-211
• /
• 1997

The optimal conditions for the production and regeneration of the protoplasts from Lentinula edodes were studied. Protoplast formation from the mycelia of L. edodes which were cultured in liquid medium showed a significantly high yield compared with that of the mycelia which were cultured on cellophane covered agar media. A mixture of Novozyme 234 (15 mg/ml) and Cellulase Onozuka R10 (10 mg/ml) in 0.6 M mannitol (pH 4) was optimal lytic enzyme for the protoplast release. The optimal incubation time and mycelia age were 3.5-4 hours at $30^{\circ}C$ and 6-8 days, respectively. Regeneration frequency was 0.18% plated onto a medium containing 0.6 M sucrose, and 0.08% plated onto a medium containing mannitol. But hardly any regeneration was observed in the media containing NaCl, KCl, or $MgSO_{4}$ More than 90% of the protoplasts contained nuclei and the nucleus number per protoplast was 1.1. The DNA content per nucleus was 5.1 pg. The diameter of the protoplast was $3-5{\mu}m$ and it had a well defined cell structure.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1996년도 춘계학술발표회논문집(2)
• /
• pp.537-542
• /
• 1996

In the present work the influence of various physical parameters on the two-phase flow behavior in a self-heated porous medium has been studied using a numerical model, that is, the effects of heat generation rate, of porosity, of particle size, and of system pressure on the dryout process. To analyze the effect of these parameters, the variation of both liquid volumetric fraction and liquid axial velocity is evaluated at the steady state or at the onset of a first boiled-out region. The analysis of computational results indicate that a qualitative tendency exists between the parameters such as heat generation rate, porosity, effective particle diameter and the temporal development of the liquid volumetric fraction field up to dryout. In addition to these parameters, a variation of fluid properties such as phase density, phase viscosity due to a change of system pressure can be used for gaining insight into the nature of two-phase flow behavior up to dryout.

• 한국전산유체공학회지
• /
• 제15권3호
• /
• pp.73-80
• /
• 2010

In this paper, we present the exact Riemann solver for the compressible liquid-gas two-phase shock tube problems. We hereby consider both isentropic and non-isentropic two-phase flows. The shock tube has a diaphragm in the mid-section which separates the liquid medium on the left and the gas medium on the right. By rupturing the diaphragm, various waves are observed on the phasic field variables such as pressure, density, temperature and void fraction in the form of rarefaction wave, shock wave and material interface (contact discontinuity). Both phases are treated as compressible fluids using the linearized equation of state or the stiffened-gas equation of state. We solve several shock tube problems made of a high/low pressure in the liquid and a low/high pressure in the gas. The wave propagations are well resolved by the exact Riemann solutions.

• Korea-Australia Rheology Journal
• /
• 제15권2호
• /
• pp.75-82
• /
• 2003

In this study, with the finite element method we numerically investigate the deformation of liquid drops surrounded by Newtonian or non-Newtonian viscous medium in the axisymmetric contraction flow. 1, 2 or 4 Newtonian or non-Newtonian drops are considered and the truncated power-law model is applied In order to describe non-Newtonian viscous behavior for both fluids. In this type of flow the drop exhibits considerably large deformation, and thus techniques of unstructured mesh generation and auto-remeshing are employed to accurately express the fluid mechanical behavior. We examine the deformation pattern of liquid drops with viscosity dependence different from that of the surrounding medium and also explain their interactions by comparing relative position or speed of drop front.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
• /
• pp.341-342
• /
• 2008

The dynamics of nano particles in LC medium under an external electric field is of theoretical and technological interest. In this work, the dynamical characteristics of fullerene $(C_{60})$ particles in liquid crystal (LC) medium under dc electric field have been investigated. This effect was studied for homogeneously aligned nematic LC cells driven by in-plane field. The $C_{60}$ was found to be aggregated in a form of cluster inside the LC medium. Hence polystytene was used to protect the aggregation of $C_{60}$ in LC medium. When the electric field was applied, the fullerenes start to move in direction of applied electric field. The density of $C_{60}$'s particles at the electrodes increase with increase in the value of applied electric field. The dynamical motions of fullerene $(C_{60})$ particles in liquid crystal (LC) suggest that fullerene can be designed for electrophoretic displays (i.e., electronic ink).

• KSBB Journal
• /
• 제13권2호
• /
• pp.155-161
• /
• 1998

The hairy roots of Crotalaria sessiliflora were induced from the tissue segments infected with Agrobacterium rhizogenes ATCC 15834. The induced hairy roots were subjected to paper electrophoresis fro the detection of opine-positive clones which were considered to have been transformed. Mannopine and agropine were presented in hairy root clones while mannopine was presented in two hairy root clones. Eight hairy root clones were selected and cultured in MS, B5 and WP media. Each of hairy root clones was showed a difference in branch pattern and growth rate. The best culture medium and culture conditions of hairy roots were in $\frac{1}{2}$MS(3% sucrose, pH 5.7) liquid medium at 25$^\circ C$, 70 rpm under dark, the growth rate in $\frac{1}{2}$MS liquid medium was increased with 210-fold more than that of inoculated hairy roots and with 2-fold more than that in MS liquid medium. Also, the adequate condition for hairy root growth was such that concentration of KH$_2PO$_4 was 1.25mM and the ratio of NH${_4}{^+}$ : NO${_3}{^-}$ was 1 to 3 in MS medium. The presence of pyrrolizidine alkaloids, monocrotaline, in the hairy roots was detected by TLC.

• 식물조직배양학회지
• /
• 제27권3호
• /
• pp.185-189
• /
• 2000

카사바 (Manihot esculenta Crantz, cv. MCol 22)의 마디 절편을 MS 기본배지에 3종류의 사이토키닌을 여러 농도로 첨가한 조건에서 2주동안 현탁배양한 결과, 고체배지에서 3주 배양된 것보다 훨씬 생장이 효과적이었다. 현탁배양된 유식물에서는 과수화현상이 나타났으나, 이들을 세사 (마사토 + 1/2농도의 크놉씨액)를 담은 유리배양병에 이식하여 생육시킨 결과, 유경에서 새 잎이 신장되면서 과수화를 벗어나 4주후에는 4~6개의 마디를 가진 유경길이 3~5 cm의 정상 유묘로 생장됨으로서, 목본식물인 카사바의 경우 마디절편의 현탁배양에 의한 대량증식의 가능성을 확인했다. 현탁배양시 저농도의 제아틴 (0.01-0.05 mg 1$^{-1}$) 처리는 BAP 최적조건에서 보다 2배나 길게 부정아 길이를 신장시켰다. 사이토키닌 처리로 부정아가 잘 발생된 유식물은 토양이식 작업을 간편하게 했으며, 토양 이식 후 부정근을 활발히 발생시켜 one step culture시스템 배양이 가능하게 했다. 과수화된 유식물은 기외에서 순화가 어려웠으나 유기물이 혼입되지 않은 세사를 담은 유리배양병에서는 비무균조건일지라도 95% 이상 순화될 수 있었다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 추계학술대회 논문집
• /
• pp.189-189
• /
• 2009

This work was focused on the dielectrophoretic force of fullerenes dispersed in liquid crystal host medium, which are investigated in the homogeneously aligned liquid crystal (NLC) cells driven by external electric field. A fullerene of 10 wt% was doped into the LC medium and its electric field induced motion was controlled by both in-plane and vertical electric field. When the electric field was applied, the fullerene start to move in direction of applied electric field. The dark, grey and white states in the proposed device can be obtained by suitable combination of the polarity of applied electric field. The w and l are the width and distance between the electrodes. The reflectance at different l was measured and was found to be increased with increasing l. The dynamical motions of fullerene particles in LC medium suggest that fullerene can be designed for electronic-paper like displays.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2002년도 제9차 국제심포지움 및 추계정기학술발표회
• /
• pp.23-23
• /
• 2002

We established hairy root cultures of F. esculentum transformed with A. rhizogenes for in vitro rutin production. Additionally, we describe the effects of different media and plant growth regulators on growth and rutin biosynthesis in buckwheat hairy root cultures. Excised leaves of P. tinctorium from 10-day-old seedlings were used as the explant material for co-cultivation with A. rhizogenes 15834. The hairy culture of Fagopyrum esculentum Moench. was established by infecting leaf explants with Agrobacterium rhizogenes 15834. About four to five weeks after co-cultivation with A. rhizogenes, 10 hairy roots were excised from the necrotic explant tissues. After repeated transfer to fresh medium for three months, ten clones were transferred to MS liquid culture medium. The growth and rutin production of each clone differently response to the MS liquid medium. Among these clones, H8, which had exhibited good growth rate and one of the highest rutin productivity, was selected for the following experimment.(중략)