• Title/Summary/Keyword: 사포

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Hydrothermal Synthesis of Saponite from Talc (활석을 이용한 사포나이트의 수열합성)

  • 배인국;장영남;채수천;류경원;최상훈
    • Journal of the Mineralogical Society of Korea
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    • v.16 no.2
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    • pp.125-133
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    • 2003
  • Saponite was synthesized from talc by hydrothermal method. The starting material was prepared by adding ($NO_3$)$Al_3$$.$$9H_2$O and Mg($NO_3$)$_2$$.$$6H_2$O solution to the talc powder. which was previously activated in air at 800 $^{\circ}C$ together with $Na_2$$CO_3$. The alkalinity of the solution was controlled by $NH_4$OH solution. The autoclaving was carried out in the closed stainless steel vessel (about 1 liter) for 40 hours under the pressure of 25 kgf/$\textrm{cm}^2$ at $ 230^{\circ}C$ The characterization of the reaction product shows that saponite was crystallized successfully. After the experimental results, pressure was not sensitive parameter in the range of 25 ∼ 75 kgf/$\textrm{cm}^2$, but longer reaction time results in better crystallinity.

Heterologous Expression of a Model Polyketide Pathway in Doxorubicin-overproducing Streptomyces Industrial Mutants (방선균 항생제 고생산 산업균주를 기반으로 한 모델 폴리케타이드의 이종숙주 발현)

  • Kim, Hye-Jin;Lee, Han-Na;Kim, Eung-Soo
    • Microbiology and Biotechnology Letters
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    • v.40 no.1
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    • pp.10-16
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    • 2012
  • The Streptomyces peucetius OIM (Overproducing Industrial Mutant) strain is a recursively-mutated and optimally-screened strain used for the industrial production of polyketide antibiotics, such as doxorubicin (DXR). Using the S. peucetius OIM mutant strain as a surrogate host, a model minimal polyketide pathway for aloesaponarin II, an actinorhodin shunt product, was cloned in a high-copy conjugative plasmid, followed by functional pathway expression and quantitative metabolite analysis. The level of aloesaponarin II production was noted as being significantly higher in the OIM strain than in the wild-type S. peucetius, as well as in the regulatory network-stimulated S. coelicolor mutant strain. Moreover, the aloesaponarin II production level was seen to be even higher in a down-regulator $wblA_{spe}$-deleted S. peucetius OIM strain, implying that the rationally-engineered S. peucetius OIM mutant strain could be used as an efficient surrogate host for the high expression of foreign polyketide pathways.

Artillery Error Budget Method Using Optimization Algorithm (최적화 알고리즘을 활용한 곡사포의 사격 오차 예측 기법)

  • An, Seil;Ahn, Sangtae;Choi, Sung-Ho
    • Journal of the Korea Society for Simulation
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    • v.26 no.3
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    • pp.55-63
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    • 2017
  • In R&D of artillery system, error budget method is used to predict artillery firing error without field firing test. The error budget method for artillery has been consistently developed but apply for practical R&D of the weapon system has been avoided because of lacks of error budget source information. The error budget source is composed of every detailed error components which affect total distance and deflection error of artillery, and most of them are difficult to be calculated or measured. Also with the inaccuracy of source information, simulated error result dose not reflect real firing error. To resolve that problem, an optimization algorithm is adopted to figure out error budget sources from existing filed firing test. The method of finding input parameter estimation which is commonly used in aerodynamics was applied. As an optimization algorithm, CMA-ES is used and presented in the paper. The error budget sources which are figured out by the presented method can be applied to compute ROC of new weapon systems and may contribute to an improvement of accuracy in artillery.