• Title/Summary/Keyword: Agitaion

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Effects and Batch Kinetics of Agitation and Aeration on Submerged Cultivation of Ganoderma Iucidum (영지의 액체배양에 미치는 통기.교반의 효과와 동력학적 특성)

  • 이학수;정재현;이신영
    • KSBB Journal
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    • v.16 no.3
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    • pp.307-313
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    • 2001
  • The effects of agitaion and aeration on mycelial growth, exo-polysaccharide (EPS) production, and substrate consumption upon the submerged cultivation of G. lucidum were investigated, and the batch kinetics of the EPS fermentation of G. lucidum were interpreted as function of agitation speed and aeration rate. In a 2.6 L jar fermenter system, the optimum agitation speed and aeration rate for EPS production were determined to be 400 rpm and 1.0 vvm, respectively. The maximum production of EPS obtained was 15 g/L. The logistic model for mycelial growth fitted the experimental data better than that determined by the Monod and the two-thirds power models. The Luedeking-Piret equation adequately modelled the kinetic data obtained for product and substrate.

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Morphological Control of Periodic Mesoporous Organosilica with Agitation

  • Park, Seong Su;Lee, Chi Heon;Jeon, Jong Hyeon;Jo, Sang Jun;Park, Dong Ho
    • Bulletin of the Korean Chemical Society
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    • v.22 no.9
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    • pp.948-952
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    • 2001
  • Periodic mesoporous organosilicas with rope-based morphology from a reaction gel composition of 1 BTME : 0.57 ODTMABr : 2.36 NaOH : 353 H2O were synthesized. While long rope-shaped product dominated in case of static synthesis condition , gyroid type products instead of rope shaped product appeared and rope shaped product disappeared with agitation. PMO with such a long rope shaped morphology is firstly reported. Additionally, various rope-based morphologies depending on the degree of bending, twisting, folding and winding of rope such as spirals, discoids, toroids, and worm-like aggregates were observed. White powdered products were characterized by X-ray diffraction, N2 sorption measurement, SEM and TEM. From XRD pattern and TEM image, ODTMA-PMO with hexagonal symmetry was identified. The pore diameter and BET surface area of ODTMA-PMO are $32.9{\AA}$ and 799 m2g-1 , respectively. Hexagonally arrayed channels run with long axis of rope and rope-based shapes with various degree of curvature, which was elucidated by using TEM images.

Cause analysis, prevention, and treatment of postoperative restlessness after general anesthesia in children with cleft palate

  • Xu, Hao;Mei, Xiao-Peng;Xu, Li-Xian
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.17 no.1
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    • pp.13-20
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    • 2017
  • Cleft palate is one of the most common congenital malformations of the oral and maxillofacial region, with an incidence rate of around 0.1%. Early surgical repair is the only method for treatment of a cleft lip and palate. However, because of the use of inhalation anesthesia in children and the physiological characteristics of the cleft palate itself combined with the particularities of cleft palate surgery, the incidence rate of postoperative emergence agitation (EA) in cleft palate surgery is significantly higher than in other types of interventions. The exact mechanism of EA is still unclear. Although restlessness after general anesthesia in children with cleft palate is self-limiting, its effects should be considered by clinicians. In this paper, the related literature on restlessness after surgery involving general anesthesia in recent years is summarized. This paper focuses on induction factors as well as prevention and treatment of postoperative restlessness in children with cleft palate after general anesthesia. The corresponding countermeasures to guide clinical practice are also presented in this paper.

Comparative Bioreactor Studies in Terms of Oxygen Transfer between Suspended and Immobilized Fungal Systems for Cyclosporin A Fermentation (Cyclosporin A 생산을 위한 액체배양과 고정화배양의 생물반응기에서의 산소전달 비교 연구)

  • 전계택
    • KSBB Journal
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    • v.9 no.2
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    • pp.211-223
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    • 1994
  • In fermentations with a 4-liter stirred tank bioreactor, a better than two-fold enhancement of the gas-liquid mass transfer coefficient$(k_La)$ in the celite-immobilized fungal cultures of Tolypocladium in flatum over the parallel conventional free-cell was observed at identical biomass concentrations, despite the higher specific oxygen uptake rate of the immobilized fungi during exponential growth. As a result oxygen sufficient conditions, i. e., dissolve oxygen(D.O.) concentrations exceeding 75% air saturation, could be maintained throughout exponential growth period of the immobilized culture, in contrast to the suspended fungal culture, whose D.O. levels fell below 50% air saturation. A linear monotonic dependence of $k_La$ upon impeller agitaion rate was found for both immobilized and conventional cultivation modes over a range of 250 to 550rpm, the slope being a function of biomass concentration for the free but not for the immobilized cell system In contrasts oxygen transfer rate was a much weaker function of aeration rate up to about 2.5 vvm for both culture configurations. Above this level, aeration rate had no further effect on the mass transfer. In addition, the immobilized cultures sustained good morphological and physiological states, leading to almost two times higher cyclosporln A (CyA) productivity overt the parallel free cell system. These experiments suggest that the celite-immobilized fungal system in a stirred tank reactor has considerable promise for scaling up cyclosporin A production in terms of high-density cultivation.

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