• Title/Summary/Keyword: Agitation

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$\alpha$-Glucosidase Inhibition by Culture Broth of Streptomyces sp. NS15 (Streptomyces sp. NS15 배양액에 의한 $\alpha$-Glucosidase 저해)

  • 백남수;김영만
    • The Korean Journal of Food And Nutrition
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    • v.11 no.6
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    • pp.640-646
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    • 1998
  • For the production of nonprotein $\alpha$-glucosidase inhibitor from the Streptomyces sp. NS15 strain, effects of initial optimum pH, nitrogen sources, carbon sources, cationic metal ions, agitation speed and aeration rate were investigated. Initial optimum pH of medium was 7.0. The most effective nitrogen and carbon sources were soybean meal 2.0%(w/v) and glucose 1.6%(w/v), respectively. The cationic metal ins had no stimulating effect on inhibitory activity of $\alpha$-glucosidase except Fe2+. Agitation speed and aeration rate were effective at 400rpm and 1vvm, respectively. In the jar-fermenter cultivation for 4 days under optimal culture conditions, the culture broth showed the inhibitory acitivity of 3,200units/ml, which is 25 times higher than that of basic medium (CYM) for porcine intestinal $\alpha$-glucosidase. The inhibitory activity of $\alpha$-glucosidase reached about 3,200units/ml after 4 days of cultivation and decreased gradually for a further two days.

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Study on Manufacturing Process Variables affecting on Characteristics of Autonomic Microcapsules (자가치료용 마이크로캡슐 특성에 영향을 미치는 제작공정 연구)

  • 윤성호;박희원;소진호;홍순지;이종근
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2003.04a
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    • pp.169-172
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    • 2003
  • Manufacturing process for autonomic microcapsules was introduced and autonomic microcapsules were manufactured by varying with various manufacturing process variables. Urea-formaldehyde resin was used for the wall of microcapsules and DCPD (dicyclopentadiene) was used for the self-healing agent. The characteristics of these microcapsules was evaluated through a particle size analyaer, an optical microscope, and a TGA. The various manufacturing process variables, such as pH and agitation speed of the emulsified solution, were considered to focus in this study. According to the results, the particle size distributions were affected on the agitation speed of the emulsified solution, and the thermal stability was influenced by pH of the emulsified solution.

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Prevention of Particulate Scale with a new winding method in the Electronic Descaling Technology (새로운 도선감는 방법을 사용한 전기장을 이용한 스케일 제거)

  • Kim, Gun-Woo;Ahn, Hee-Sub;Sohn, Chang-Hyun
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.180-186
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    • 2000
  • This paper presents a new winding method in the electronic descaling(ED) technology. The ED technology Produces an oscillating electric field via the Faraday's law to Provide necessary molecular agitation to dissolved mineral ions. But present method gives another agitation force to mineral ions, which is Lorentz's force. Experiments were peformed at various Renolds number. A series of tests was conducted, measuring pressure drop across test section and the overall heat transfer coefficient as a function of time. In order to accelerate the rate of fouling, artificial hard water of 1000ppm $CaCO_3$ was used throughout the tests. The results show that the new method accelerates collision of mineral ions and improvs efficiency of system.

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A Study of Antibacterial and Aromatic Fibers Vsing Microencapsulation of Antibiotics and Perfume (1) -Microencapsulation of Antibiotics/Perfume- (항균제 및 향료의 마이크로캡슐을 이용한 항균 . 방향섬유에 관한 연구(1) -항균제/향료의 마이크로캡슐화 -)

  • Kim, Ho-Jung;Park, Cha-Cheol;Kim, Han-Do
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.3
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    • pp.512-518
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    • 1996
  • Microcapsules containing 2, 4, 4'-trichloro-2-hydroxydiphenyl ether and perfumes were prepared by the coacervation using poly (vinyl alcohol) and crosslinking agents. Effects of dispersing agents, core materials, agitating speed and crosslinking agents on microcapsule size were investigated. The mean and deviation of microcapsule diameters decreased with increasing agitation speed. The diameters of m;crocapsules decreased with increasing dispering agent concentration at 6, 000 rpm of agitation speed, but it was not changed at 10, 000 rpm. The dispering effect of PVA is better than that of gum arabic. The slight increase in the diameter of microcapsule was observed when the amount of core material was increased. As the amount of crosslinking agent was increased, the diameter of microcapsule was decreased.

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Computer Simulation of Hardenability Characteristics of Alloy Steel for Structural Purposes (컴퓨터 시뮬레이션에 의한 구조용 합금강의 경화능특성 해석)

  • Kim, K.S.;Hong, C.P.
    • Journal of the Korean Society for Heat Treatment
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    • v.2 no.2
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    • pp.1-10
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    • 1989
  • In this study, the specimens of SCM 22 H steel were quenched in oil and water baths at various agitation conditions in order to investigate the effects of quenchants and agitation conditions on the quench-hardening. A multi-channel temperature measurement apparatus was employed to obtain the cooling curves at several predetermined positions of specimens. Microstructural observation and hardness test were also carried out. Computer simulation of heat treating process was carried out using the modified finite difference method. Prediction of thermal history and hardness distribution by 2-dimensional computer analysis was in good agreement with the experimental results. It was found that the quantitative design of heat treating process can be made by the computer aided heat-treating analysis.

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Effects of Stireed Tank Bioreactor Scale-up on Cell Growth and Alkaloids Production in Cell Cultures of Eschscholtzia californica (탱크 교반형 생물반응기의 scale-up이 Eschscholtzia californica 세포생장 및 알칼로이드 생성에 미치는 영향)

  • 유병삼;변상요
    • KSBB Journal
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    • v.13 no.6
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    • pp.700-705
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    • 1998
  • Studies were made to investigate effects of the scale-up of stirred tank bioreactors on cell growth and alkaloids production for suspension cultures of Eschscholtzia californica. In the 1.5 L STR, cell lysis was observed at 110 rpm or higher agitation speed. The agitation speed of 30 L STR was 43.7 rpm to maintain the same shear stress developed in 1.5 L STR of 100 rpm. As a result of scale-up from 1.5 L to 30 L STR, the specific growth rate was decreased from 0.12 to 0.07 day-1. The alkaloids productivity was also decreased from 0.24 to 0.14 mg/L-day. Changes of mixing performance and oxygen transfer were studied to explain the decrease of cell growth and alkaloids production. Decreased oxygen transfer rate coefficient(KLa) and increased mixing time by the scale-up was observed at various aeration rates.

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Development of Coencapsulating Technology for the Production of Chitosanoligosaccharides

  • Lee, Ki-Sun;Chio, Myeong-Rak;Lim, Hyun-Soo
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.5
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    • pp.345-349
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    • 2000
  • To easily separate chitosanoligosaccharides by size exclusion, an coencapsulating technology of substrate and enzyme was developed. The membrane was composed of alginate and a divalent cation such as calcium. Chitosan and chitosanase were enveloped in this membrane and the product released to medium by size exclusion. The capsule was stabilized in a 2% acetic acid solution (pH 5.0) containing 0.145 M CaCO$_3$. The leakage of substrate caused by the agitation speed was controlled by increasing alginate and CaCO$_3$concentrations. The lower limit of the alginate concentration and the agitation speed were 0.5% and 49rpm, respectively. Membrane thickness and capsule diameter were 10$\mu\textrm{m}$ and 2.5mm, respectively. By TLC analysis, the composition of chitosanoligosaccharides were mainly 3-6 mers. The molecular weight distribution of the released oligosaccharides ranged from 262 to 3624 Da by GPC.

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A Case of Acute Psychosis after Sibutramine Ingestion (시부트라민(sibutramine) 음독 후 발생된 급성 정신병증 1례)

  • Kim, Hyung-Min;Woo, Seon-Hee;Choi, Se-Min;So, Byung-Hak
    • Journal of The Korean Society of Clinical Toxicology
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    • v.7 no.2
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    • pp.176-179
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    • 2009
  • A 38-year-old woman was admitted to our hospital due to agitation, nausea, chest discomfort, tachycardia and hypertension 6h after ingesting approximately 60 capsules of sibutramine. The woman developed the clinical features of acute psychosis, including auditory hallucination, agitation and paranoid ideation, on day 2. No relevant changes were detected on the laboratory examinations or on the electrocardiogram throughout the period of hospitalization. She was treated with risperidone and benzodiazepine. The symptoms subsequently resolved completely with cessation of the provoking agent. The patient was discharged on day 7 and the follow-up revealed no sequelae for 5 months.

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The Extablishment of Optimum Cultured Conditions for Manufacturing Garlic Vinegar (마늘식초 제조공정을 위한 최적발효조건의 설정)

  • 최용희;고은정;허상선
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.1
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    • pp.102-108
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    • 1998
  • This study was performed to establish manufacturing of garlic vinegar which has medical action component of garlic and functionality of vinegar. Optimum alcohol concentration, and garlic juice concentration for the mpnufacturing of garlic vinegar were 5%, 10%, respectively, and the optimum conditions were obtained when the fermentation was carried out at agitation of agitation of 120rpm and temperature of 3$0^{\circ}C$. The acetic acid content of optimum condition was 4.87% and thiosulfinate content was 37.5mg after 20days fermentation. The major organic acid compositions in garlic vinegar were oxalic acid, citric acid, malic acid and acetic acid, and free amino acid compositions were aspartic acid, threonine, serine, glutamic acid, alanine etc.

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Adhesion improvement of electroless plated Ni layer by modifying zincating process (징케이트 공정 변화에 따른 무전해 니켈 도금 막의 접착력향상)

  • 이성기;진정기;김영호
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2002.05a
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    • pp.109-114
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    • 2002
  • The adhesion of electroless plated Ni layer on Al/Si substrates has been investigated. The zincating treatment was conducted with a conventional method and a modified method. In a modified method, ultrasonic agitation was applied during zincating. Adhesion strength was evaluated by a pull-off test. The ultrasonic agitation during zincating increased the nucleation density of Zn particles and refined Zn particle size. the adhesion strength of electroless Ni layer deposited on the modified zincated surface was higher than that on the conventionally zincated surface. the improvement of adhesion was attributed to the fine and dense Zn particles.

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