• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.809-810
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• 2011

• Journal of the Korean Chemical Society
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• v.33 no.3
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• pp.273-280
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• 1989

The spectra of the $Co^{II}CyDTA$(CyDTA: cyclohexyldiaminetetraacetic acid) complex have been measured in aqueous solution of pH = 6-13.2. The red shift of the spectrum in the more basic solution was ascribed to the transformation of $CoCyDTA^{2-}$ into $CoCyDTA(OH)^{3-}$. The equilibrium constant, $K_{OH} = [CoCyDTA(OH)^{3-}]/[CoCyDTA^{2-}][OH^-]$ was $75M^{-1}$ at $40^{\circ}C$. The electron transfer reactions of $CoCyDTA^{2-}$ and $CoCyDTA(OH)^{3-}$ with $Fe(CN)_6^{3-}$ have been studied using spectrophotometric technique in the range of pH applied to the determination of equilibrium constant. The pseudo first-order rate constants observed ($k_{obs}$) were not changed upto pH = 10.8, but increased with increasing pH in the range of pH = $10.8{\sim}13.0$. The rate law reduced in the range of pH = 6-13 was $k_{obs} = (k_3[CoCyDTA^{2-}] + k_4[CoCyDTA(OH)^{3-}])/(1+K_1[CoCyDTA^{2-}])$. The rate constants of the reactions (3a) and (3b), $k_3$ and $k_4$ respectively have been determined to be 0.529 and $4.500M^{-1}sec^{-1}$ at $40^{\circ}C$. The activation entropies (147{\pm}1.1JK^{-1} mol^{-1}$ at pH = 10.8) and activation volumes $(6.25cm^3mol^{-1}, pH = 10.8)$ increased with increasing pH, while the activation enthalpy (12.44 ${\pm}$ 0.20 kcal/mole) was independent of pH. Using the pH effect on the rate constants, the activation entropies and the activation volumes, the mechanism of the electron transfer reaction for $Co^{II}-Fe^{III}$ system was discussed.

• Clinical and Experimental Vaccine Research
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• v.13 no.2
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• pp.155-165
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• 2024

Purpose: Pertussis bacteria have many pathogenic and virulent antigens and severe adverse reactions have occurred when using inactivated whole-cell pertussis vaccines. Therefore, inactivated acellular pertussis (aP) vaccines and genetically detoxified recombinant pertussis (rP) vaccines are being developed. The aim of this study was to assess the safety profile of a novel rP vaccine under development in comparison to commercial diphtheria-tetanus-acellular pertussis (DTaP) vaccines. Materials and Methods: The two positive control DTaP vaccines (two- and tri-components aP vaccines) and two experimental recombinant DTaP (rDTaP) vaccine (two- and tri-components aP vaccines adsorbed to either aluminum hydroxide or purified oat beta-glucan) were used. Temperature histamine sensitization test (HIST), indirect Chinese hamster ovary (CHO) cell cluster assay, mouse-weight-gain (MWG) test, leukocytosis promoting (LP) test, and intramuscular inflammatory cytokine assay of the injection site performed for safety assessments. Results: HIST results showed absence of residual pertussis toxin (PTx) in both control and experimental DTaP vaccine groups, whereas in groups immunized with tri-components vaccines, the experimental tri-components rDTaP absorbed to alum showed an ultra-small amount of 0.0066 IU/mL. CHO cell clustering was observed from 4 IU/mL in all groups. LP tests showed that neutrophils and lymphocytes were in the normal range in all groups immunized with the two components vaccine. However, in the tri-components control DTaP vaccine group, as well as two- and tri-components rDTaP with beta-glucan group, a higher monocyte count was observed 3 days after vaccination, although less than 2 times the normal range. In the MWG test, both groups showed changes less than 20% in body temperature and body weight before the after the final immunizations. Inflammatory cytokines within the muscle at the injection site on day 3 after intramuscular injection revealed no significant response in all groups. Conclusion: There were no findings associated with residual PTx, and no significant differences in both local and systemic adverse reactions in the novel rDTaP vaccine compared to existing available DTaP vaccines. The results suggest that the novel rDTaP vaccine is safe.

• BMB Reports
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• v.30 no.2
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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.

• Journal of Microbiology and Biotechnology
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• v.12 no.5
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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.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.4
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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.

• Journal of Korean Society for Quality Management
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• v.47 no.1
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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.

• Journal of the Korean Society of Safety
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• v.35 no.1
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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.

• Journal of Korean Society for Quality Management
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• v.44 no.3
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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.

• Journal of the Korean Ceramic Society
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• v.35 no.6
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• pp.640-646
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• 1998

Nucleation and crystallzation of a quaternary glass system for lead titanate glass-ceramics were in-vestigated using DTA(differential thermal analysis ) with variation of nucleation temperature and crystal growth time. Glass samples containing 60mol% of PbO-{{{{ { TiO}_{2 } }} were prepared from melts by the conventional normal cooling method in a cylindrical brass mould. The glass sample was nucleated between 40$0^{\circ}C$ and 50$0^{\circ}C$ for a given time and showed the maximum nucleation rate at 46$0^{\circ}C$ The DTA crystallization peak temperature decreased with increasing nucleating time and decreasing heating rate during DTA runs which indicated an increase of the number of nuclei produced in the system.