• Title/Summary/Keyword: 현탁액

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The Optical Properties of Monocationic Zeolite Suspensions (Monocationic Zeolite 현탁액(懸濁液)의 광학적(光學的) 특성(特性))

  • Kang, Shin-Jyung;Choi, Jyung
    • Applied Biological Chemistry
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    • v.29 no.2
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    • pp.159-163
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    • 1986
  • The optical properties of monocationic zeolite suspension adsorbed with each of $Na^+$, $NH_4^+$, $Ca^{2+}$, and $Al^{3+}$ were studied in the wavelength range $200{\sim}800nm$. The results were as follows. 1. The optical density of zeolite suspension seemed to be affected by the light absorption of zeolite particles at the wavelength range of $200{\sim}300nm$ and by the light scattering of zeolite particles at wavelength of $300{\sim}800nm$. 2. At the wavelength range of $380{\sim}800nm$, the optical densities of monocationic zeoliteg differed mutually according to adsorbed cations and increased in the order of $Al-\;>\;Ca-\;>\;NH_4->\;Na-zeolite$ suspension. 3. It was convenient that at the wavelength range of $380{\sim}800nm$, the diluted suspension of zeolite was measured in the short wavelength and the concentrated suspension of zeolite was measured in the long wavelength. 4. Zeolite particles in zeolite suspension were aggregated and the size of aggregation size was larger in the order of $Al-\;>\;Ca-\;>\;Na-\;>\;NH_4-zeolite$.

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Development of a Quantitative Induction Method for Chondromyces crocatus Fruiting Body Formation (Chondromyces crocatus 자실체 형성의 정량적 유도 방법 개발)

  • Lee, Chayul;Shin, Hyejin;Cho, Kungyun
    • Korean Journal of Microbiology
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    • v.50 no.3
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    • pp.173-178
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    • 2014
  • We have developed a method for the preparation of dispersed cell suspensions of Chondromyces crocatus, which is essential for quantitative studies of fruiting body formation. Cells of C. crocatus have a tendency to aggregate in liquid, hindering quantitative studies. However, cells grown on casitone-yeast extract agar plates, containing 3% agar, allowed the preparation of well-dispersed cell suspensions. Cell suspensions at a concentration of $2{\times}10^8cells/ml$, obtained by using this method, developed typical C. crocatus fruiting bodies when placed as $20{\mu}l$ spots on agar plates with no nutrient supplementation. The addition of nutrients such as casitone altered or inhibited fruiting body formation. Fruiting body branch formation increased with increasing agar content. Under optimum conditions, the formation of fruiting body structure in C. crocatus KYC2823 was completed within 24 h.

Computer simulation of agglomeration in colloidal alumina powder suspension (콜로이드성 알루미나 분말 입자의 응집현상의 컴퓨터 시뮬레이션)

  • 김종철;오근호
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.2
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    • pp.224-230
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    • 1999
  • Agglomeration of colloidal alumina particles in a suspension is simulated. Particles in a suspension have potential energies between them and move to decrease the summation of all the potential energies between particles. The effects of various types of potential curves on particle agglomeration were checked. Strong short range attractive energy without repulsive energy barrier makes small strong clusters with disordered network structure but weak short-range force with big repulsive energy barrier makes big agglomerates with a close packing structure. As particles are agglomerated the potential energy with strong repulsive energy barrier between agglomerates gradually decreases the importance of the repulsive energy barrier and induces a different type of agglomeration behavior.

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Identification, Pathogenicity and Host Range of a Potential Bioherbicide, Epicoccosorus nematosporus, Causing Fingerprint Stem Blight on Water Chestnut, Eleokaris kuroguwai (생물제초제로서의 올방개 지문무늬병균(Epicoccosorus nematosporus)의 동정, 병원성 및 기주범위)

  • 홍연규;조재민;김재철;엄재열
    • Korean Journal Plant Pathology
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    • v.12 no.1
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    • pp.58-65
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    • 1996
  • 한국의 수도 재배 지대에서 문제가 되는 다년생 논잡초 올방개에 자연상태에서 기주특이적으로 기생하여 올방개 줄기를 고사시키는 병원균인 Epicoccosorus nematosporus를 우리나라에서 처음으로 분리, 동정하였으며, 이 병을 올방개 지문무늬병(Finegerprint stem blight disease of water chestnut)으로 명명하였다. 분생포자는 분생자층 위에서 형성이 되며 무격막, 단핵이며, 44.5~72 $\mu\textrm{m}$ 크기의 양끝이 뾰족한 선충 모양이다. 갈색의 병반상에서 흑색의 분생자층은 발달하여 특이한 지문무늬를 형성하는 것이 특징이다. 이 병균은 전국의 올방개가 자라는 논에서 분포하며 매년 발생한다. 온실 접종시 초기의 병징은 접종후 4~5일만에 바늘끝 모양의 회흑색의 반점으로 나타나며 시간이 경과하면서 병반은 급속도로 진전하여 접종후 10~15일 정도 후 약 10mm 내외의 갈색병반이 형성이 되어 올방개 줄기를 감싸고 그 줄기 전체는 고사하게 된다. 분생포자 현탁액(3.2$\times$10\ulcorner conidia/ml)을 온실 조건하에서 분무접종 하였을 때 20일 이내에 약 78.0~93.3% 정도의 고사율을 나타내었다. 올방개 지문무늬병균의 분생포자 현탁액(3.2$\times$10\ulcorner conidia/ml)을 온실 조건하에서 벼 등 31개 작물과 피 등 15개 잡초의 유묘에 접종하였을 때 올방개를 제외한 어떤 식물에도 병원성이 없었다.

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Screening of Penicillium sp. Showing Herbicidal Activity on Trifolium repens L. (토끼풀(Trifolium repens L.)에 제초활성을 나타내는 Penicillium sp.의 탐색)

  • Kim, Pan-Kyung;Park, Dong-Jin;Choi, Soon-Yong;Kim, Chang-Jin
    • Applied Biological Chemistry
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    • v.39 no.6
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    • pp.455-459
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    • 1996
  • Nine hundred and eighty fungal strains were isolated from lesions of Trifolium repens L. and various weeds. Among them, F40362, F40496, F40497 strains were selected by the screening of herbicidal activity on Trifolium repens L. and Zoysia japonica. Selected three strains showed selective activity between Trifolium repens L. and Zoysia japonica, and were identified as Penicillium sp.

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The Effect of Heating Rate by Ohmic Heating on Rheological Property of Corn Starch Suspension (Ohmic Heating에 의한 가열속도 변화가 옥수수전분의 물성특성에 미치는 영향)

  • Lee, Seok-Hun;Jang, Jae-Kweon;Pyun, Yu-Ryang
    • Korean Journal of Food Science and Technology
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    • v.37 no.3
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    • pp.438-442
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    • 2005
  • Granule swelling is essential phenomenon of starch gelatinization in excess water, and characteristic of heated starch dispersion depends largely on size and distribution of swelled starch granule. Although swelling characteristic of starch granules depends on type of starch, heating rate, and moisture content, influence of heating rate on swelling phenomenon of starch granule has not been fully discussed, because constant heating rate of starch dispersion cannot be obtained by conventional heating method. Ohmic heating, electric-resistant heat generation method, applies alternative current to food materials, through which heating rate can be easily controlled precisely and conveniently at wide range of constant heating rates. Starch dispersion heated at low heating rates below $7.5^{\circ}C/min$ showed Newtonian fluid behavior, whereas showed pseudoplastic behavior at heating rates above $16.4^{\circ}C/min$. Apparent viscosity of starch dispersion increased linearly with increasing heating rate, and yield stress was dramatically increased at heating rates above $16.4^{\circ}C/min$. Average diameter of corn starch granules during ohmic heating was dramatically increased from $30.97\;to\;37.88\;{\mu}m$ by increasing heating rate from $0.6\;to\;16.4^{\circ}C/min$ (raw corn starch: $13.7\;{\mu}m$). Hardness of starch gel prepared with 15% corn starch dispersion after heating to $90^{\circ}C$ at different heating rates decreased gradually with increasing heating rate, then showed nearly constant value from $9.4\;to\;23.2^{\circ}C/min$. Hardness increased with increase of heating rate higher than $23.2^{\circ}C/min$.

The Effect of Cement Milk Grouting on the Deformation Behavior of Jointed Rock Mass (시멘트현탁액 주입에 의한 절리암반의 역학적 특성 변화)

  • 김태혁;이정인
    • Tunnel and Underground Space
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    • v.13 no.5
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    • pp.331-343
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    • 2003
  • Though the Grouting has been in use for a long time, it is still regarded as an technique rather than engineering. The study of ground improvement by grouting is rare especially in jointed rock mass. In this study, biaxial compression tests were performed in the jointed rock mass models with .ough surfBce joints assembled with blocks before and after grouting. The load-deformation curves of the jointed rock masses showed a non-linear relationship before grouting but showed a relatively linear deformaion behavior after grouting. Improvement ratio (deformation modulus after grouting/deformation modulus before grouting) decreased with increasing joint spacing and lateral stress. Improvement ratio decreased exponentially with increasing deformation modulus of the rock mass model before grouting. Three-dimensional FDM analysis was performed to a highway tunnel case using experimental data of grouted rock. The convergence of the tunnel predicted after grouting by the numerical modelling coincided with those attained from the field measurement.