• 제목/요약/키워드: DTA

검색결과 956건 처리시간 0.031초

Co(II)-CyDTA와 Fe(III)-CN 착이온간의 전자이동반응에서 활성화파라미터 $({\Delta}H^{\neq},\;{\Delta}S^{\neq}$${\Delta}V^{\neq})$ 와 반응메카니즘 (Mechanism and Activation Parameters $({\Delta}H^{\neq},\;{\Delta}S^{\neq}$ and ${\Delta}V^{\neq})$ of Electron Transfer Reaction Between $Co^{II}CyDTA\;and\;Fe^{III}$CN Complex Ions)

  • 박유철;김성수
    • 대한화학회지
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    • 제33권3호
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    • pp.273-280
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    • 1989
  • Co(II)-CyDTA 착물의 흡수스펙트럼을 pH = $6.0{\sim}13.2$의 수용액에서 측정하였다. 흡수에너지는 pH가 증가할수록 낮은 에너지로 이동하였고, 이 현상은 $CoCyDTA^{2-}$$CoCyDTA(OH)^{3-}$간의 평형상수 $K_{OH} = [CoCyDTA(OH)^{3-}]/[CoCyDTA^{2-}][OH^-]$로 설명할 수 있었고, 그 값은 $40^{\circ}C$에서 $75M^{-1}$이었다. Co(II)-CyDTA와 Fe(III)-CN 착이온간의 전자이동반응은 $K_{OH}$ 측정과 같은 용액조건에서 분광광도법을 이용하여 고찰하였다. 측정한 $k_{obs}$는 pH = 10.8까지는 거의 일정하였으나 pH > 10.8에서는 pH의 증가에 따라 증가하였다. pH = $6.0{\sim}13.0$에서 적용할 수 있는 속도법칙은 $k_{obs} = (k_3[CoCyDTA^{2-}] + k_4[CoCyDTA(OH)^{3-}])/(1+K_1[CoCyDTA^{2-}])$이었다. 반응 (3a)와 (3b)의 속도상수 $k_3$$k_4$$40^{\circ}C$에서 각각 $0.529M^{-1}sec^{-1}$$4.500M^{-1}sec^{-1}$이었다. 활성화엔트로피(147{\pm}1.1JK^{-1} mol^{-1}, pH = 10.8)$와 활성화체적$(6.25cm^3mol^{-1}, pH = 10.8)$은 pH가 증가할수록 증가하였지만, 활성화엔탈피$(12.44{\pm}0.20 kcal mol^{-1})$는 pH의 영향을 받지 않았다. 속도상수, 활성화엔트로피, 활성화체적에 대한 pH의 영향을 각각이용하여 Co(II)-Fe(III)의 전자이동 반응메카니즘을 논의하였다.

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Preparation of Diphtheria Toxin A Chain from Escherichia coli

  • Lee, Jong-Soo;Yoon, Kyoung-Bum;Park, Jong-Won;Choi, Suk-Jung
    • BMB Reports
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    • 제30권2호
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    • pp.144-149
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    • 1997
  • An expression vector was constructed containing the gene encoding diphtheria toxin A (DTA) which was placed after a T7 promoter. Cytoplasmic expression of the DTA gene resulted in the formation of an insoluble inclusion body. The inclusion body was collected after the complete lysis of the cell, and subsequent washing with 0.1% Triton X-100 released 16~30% of DTA protein from the inclusion body along with other contaminating proteins. The released DTA protein was purified by dialysis. The remaining pellet was dissolved in 8 M urea containing 5% ${\beta}-mercaptoethanol$, and the denatured DTA was renatured by the dilution-dialysis method. The total yield was 35%, and about 5 mg DTA was obtained from 1 L culture. The DTA protein has a free sulfhydryl group exposed to the protein surface, and was shown to have a tendency to dimerize through disulfide formation in the absence of ${\beta}-mercaptoethanol$. The utility of the sulfhydryl group was tested for the construction of recombinant toxins.

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Development of a Quadrivalent Combined DTaP-HepB Vaccine with a Low Toxicity and a Stable HBsAg Immunogenicity

  • Bae, Cheon-Soon;Park, Kwung-Nam;Ahn, Sang-Jeom;Kim, Jong-Su;Hur, Byung-Ki
    • Journal of Microbiology and Biotechnology
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    • 제12권5호
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    • pp.787-792
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    • 2002
  • When developing a combined DTaP-HepB vaccine, toxicity and HBsAg immunogenicity are both important considerations. Thus, for a combined DTaP-HepB vaccine with a low toxicity, the effect of the DTaP content and $Al(OH)_3$, gel concentration on the vaccine toxicity was investigated. Within the range studied, the higher the concentrations, the higher the vaccine toxicity. The importance of the tetanus toxoid content in the combined DTaP-HepB vaccine was also revealed. A higher concentration of the tetanus toxoid was found to have a negative effect on the stability of the HBsAg immunogenicity in the combined vaccine. Accordingly, considering the factors affecting toxicity and HBsAg immunogenicity, a novel DTaP-HepB vaccine (30 Lf/ml of diphtheria toxoid, 5 Lf/ml of tetanus toxoid, 10 $\mu\textrm{g}$ PN/ml of acellular pertussis, 24 $\mu\textrm{g}$/ml of HBsAg, and 500 $\mu\textrm{g}$ Al/ml of $Al(OH)_3$ gel) was developed. It has a low toxicity and a stable HBsAg immunogenicity and also satisfies the potency criteria of K-FDA for a combined DTaP vaccine.

함정 운항에 따른 조명등기구 가진력 비교 연구 (A Comparative Study on Exciting Force for Luminaire of Naval Vessels According to Sailing Condition)

  • 박미유;조흥기;이관우;유영수;조규룡
    • 한국군사과학기술학회지
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    • 제15권4호
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    • pp.390-397
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    • 2012
  • According to sailing condition, an exciting force for luminairie of naval vessels was measured and analyzed. A naval combat service support boat and P${\bigcirc}{\bigcirc}$(patrol killer guided missile) were selected as a target naval vessel. Due to their small size and fast speed, they received excessive vibration than other bigger naval vessels like destroyer. The vibration of luminairie was measured on their cruising and maximum speed. This could analyze exciting force for luminairie of naval vessels. Using this analyzed data, the validity of military standard for naval vessel was verified.

LST-II급 함정 함수 LCM 거치대 손상에 대한 개선방안 연구 (A Study on Improvement Plan for LST-II LCM Cradle Damage)

  • 최상민;백용관;정영인;황인하;백제성
    • 품질경영학회지
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    • 제47권1호
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    • pp.139-150
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    • 2019
  • Purpose: LST-II is a special naval ship to carry out landing operations by transporting tanks, armored vehicles and military vehicles. Bad weather, maximum wave height of 4-5 m, caused damage to the LCM cradles while the LST-II No.O ship was moving to Thailand for training in February 2016. Methods: Based on the results of the field check, DTaQ conducted a study on the causes analysis and improvement measures. Results: The improvement plan that was derived was verified through a structural analysis and the improvement plan was applied to the follow-up ships. Conclusion: The improvement of LCM cradle has increased the safety of the crew and landing forces, and improved the operational efficiency.

다수기 PSA 수행을 위한 새로운 정량화 방법 (A New Quantification Method for Multi-Unit Probabilistic Safety Assessment)

  • 박성규;정우식
    • 한국안전학회지
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    • 제35권1호
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    • pp.97-106
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    • 2020
  • The objective of this paper is to suggest a new quantification method for multi-unit probabilistic safety assessment (PSA) that removes the overestimation error caused by the existing delete-term approximation (DTA) based quantification method. So far, for the actual plant PSA model quantification, a fault tree with negates have been solved by the DTA method. It is well known that the DTA method induces overestimated core damage frequency (CDF) of nuclear power plant (NPP). If a PSA fault tree has negates and non-rare events, the overestimation in CDF drastically increases. Since multi-unit seismic PSA model has plant level negates and many non-rare events in the fault tree, it should be very carefully quantified in order to avoid CDF overestimation. Multi-unit PSA fault tree has normal gates and negates that represent each NPP status. The NPP status means core damage or non-core damage state of individual NPPs. The non-core damage state of a NPP is modeled in the fault tree by using a negate (a NOT gate). Authors reviewed and compared (1) quantification methods that generate exact or approximate Boolean solutions from a fault tree, (2) DTA method generating approximate Boolean solution by solving negates in a fault tree, and (3) probability calculation methods from the Boolean solutions generated by exact quantification methods or DTA method. Based on the review and comparison, a new intersection removal by probability (IRBP) method is suggested in this study for the multi-unit PSA. If the IRBP method is adopted, multi-unit PSA fault tree can be quantified without the overestimation error that is caused by the direct application of DTA method. That is, the extremely overestimated CDF can be avoided and accurate CDF can be calculated by using the IRBP method. The accuracy of the IRBP method was validated by simple multi-unit PSA models. The necessity of the IRBP method was demonstrated by the actual plant multi-unit seismic PSA models.

ISO/IEC/IEEE 15288 기반 양산단계 무기체계 부품국산화 체계공학 개발관리 절차 적용 연구 (A Study on The Mass Production Weapon System Parts Localization System Engineering Development Management Process Application based on ISO/IEC/IEEE 15288)

  • 김장은;심보현;조유습;성인철;한동석
    • 품질경영학회지
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    • 제44권3호
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    • pp.541-552
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    • 2016
  • Purpose: In this study, we propose that how to approach a effective system engineering and optimize system engineering management process for the mass production weapon system parts localization development process and success in DTaQ. Methods: To approach a effective system engineering for the mass production weapon system parts localization, we analyze a weapon system acquisition process and system engineering process of Republic of Korea and DTaQ parts localization business regulations in advance. after results of analysis of them, we implement a optimized parts localization development system engineering based on ISO/IEC/IEEE 15288. Results: In order to apply International Standard ISO/IEC/IEEE 15288 to the mass production weapon system parts localization development process, we compare the mass production weapon system parts localization acquisition environment with ISO/IEC/IEEE 15288 and analyze them. therefore, It is possible to implement a part of concept stage and development stage of ISO/IEC/IEEE total life cycle stage for the mass production weapon system parts localization development process. To achieve the technical review milestones of DTaQ parts localization business regulations in the selected stages of ISO/IEC/IEEE, the development and management agency perform 2 high rank process and 19 low rank process specified in ISO/IEC/IEEE. Conclusion: When the development and management agency perform the mass production weapon system parts localization development using the proposed system engineering approach, they should easily meet milestone through the clarified requirement and simplified System Engineering output documents in limited development period.

PbO-TiO$_2$-B$_2$O$_3$-BaO 계 유리에서 PbTiO$_3$ 결정의 핵생성 곡선 결정을 위한 열시차분석법의 응용 (Determination of the Nucleation Rate Curve for Lead Titanate in the PbO-TiO$_2$-B$_2$O$_3$-BaO by Diffferential Thermal Analysis)

  • 이선우;심광보;오근호
    • 한국세라믹학회지
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    • 제35권6호
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    • pp.640-646
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    • 1998
  • PbO-TiO2-B2O3-BaO계 유리에서 PbTiO3의 핵생성 및 결정화를 위한 최적조건의 확입을 위해 핵생성 속도 곡선을 도출하고자 열시차 분석법(DTA)을 응용하였다. PbTiO3의 함량비가 60mol%인 4성분계 유리 샘플은 용융액으로부터 자연 냉각시켜 제조되었으며, 핵생성을 위해 유리 샘플은 40$0^{\circ}C$와 50$0^{\circ}C$ 사이에서 열처리하였다. 이때 46$0^{\circ}C$에서 핵생성 속도가 최대값을 나타내었다. DTA의 결정화 피크 온도는 핵생성을 위한 열처리시간이 증가함에 따라 감소하였으며, DTA의 승온속도에 비례하여 증가하였다. 이러한 결과는 계에 생성된 핵의 밀도가 핵생성 처리온도와 시간의 증가에 따라 증가함을 보여주고 있다.

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우리나라 영아에서 3가 정제 백일해 항원 DTaP 백신의 면역원성 및 안전성 (The immunogenicity and safety of three-component DTaP vaccine in Korean infants)

  • 강진한;김종현;이정현;이수영;홍영진;김창휘
    • Clinical and Experimental Pediatrics
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    • 제50권4호
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    • pp.355-362
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    • 2007
  • 목 적 : 3가 항원 DTaP 백신을 3회 기초 접종 받은 건강한 국내 영아에서 면역원성 및 안전성을 평가하고자 하였다. 방 법 : 2004년 4월부터 2005년 4월까지 5개 연구 참여 대학병원에서 제태기간 32주 이상에서 태어난 건강한 영아에게 생후 2, 4, 6개월에 3가 항원 DTaP 백신($Infanrix^{(R)}$)을 대퇴부 전외측에 접종하여 접종 전 혈청과 3차 접종 1개월 후 혈청에서 디프테리아, 파상풍, PT, FHA, PRN 항원에 대한 항체를 측정하여 면역원성을 평가하였고, 접종 후 3일 내에 발생이 예상되는 국소 및 전신 이상반응을 적극 관찰하였고 3주내에 발생한 모든 이상반응을 관찰하여 안전성 평가를 실시하였다. 한편, 2가 항원 DTaP 백신을 접종 받은 14명을 대조군으로 설정하여 연구군과 동일한 방법으로 면역원성을 평가하여 비교하였다. 결 과 : 60명에서 실시된 연구군의 면역원성 평가에서 디프테리아, 파상풍, FHA, PRN 항원에 대한 항체 양전율은 100%이었고, PT 항원에 대한 항체 양전율은 98.3%이었다. 한편 대조군에서 디프테리아, 파상풍, PT, FHA 항원에 대한 항체 양전율은 100%이었으나 PRN 항원에 대한 항체 양전율은 50%이었다. 147명에서 확인된 이상반응 평가에서 연구 기간동안 연구 백신과 인과관계가 있는 중증 이상반응은 없었고, 3일 내에 특이한 치료 및 처치가 없이 자연 소멸되는 국소 및 전신 이상반응만 관찰되었으며 접종 차수별 이상반응의 증가도 없었다. 결 론 : 이상의 결과를 볼 때에 3가 항원 DTaP 백신($Infanrix^{(R)}$)은 국내 영아 기초 접종에 유효한 백신임을 확인할 수 있었고, 국내에서 가장 많이 사용되고 있는 2가 DTaP 백신에 비해 PRN항원에 대한 항체의 면역원성이 높은 이점이 있음을 확인하였다. 그러나 향후 더욱 많은 대상을 통한 연구가 이루어져 이런 결과를 재입증하여야 할 것이고, 추가 접종에 대한 동일한 연구도 요구된다.