• Food Science and Preservation
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• v.30 no.1
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• pp.132-145
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• 2023

In this study, culture conditions were optimized to confirm the feasibility of Acetobacter pasteurianus as a starter for fermentation vinegar. Acetobacter pasteurianus strain can be used as a food ingredient. The optimal temperature and pH conditions of the selected Acetobacter pasteurianus SRCM101388 were 28℃ and pH 6.00, respectively. The response surface methodology (RSM) was used to optimize the composition of the medium, and Plackett-Burman design (PBD) was used to obtain the effective selection of culture medium, resulting in that glucose, sucrose, and yeast extract had the highest effect on increasing biomass. The optimal concentration, which was performed by central composite design (CCD), were determined to be 10.73 g/L of glucose, 3.98 g/L of sucrose, and 18.73 g/L of yeast extract, respectively. The optimal concentrations of trace elements for the production of biomass were found to be 1 g/L of ammonium sulfate, 0.5 g/L of magnesium sulfate, 2 g/L of sodium phosphate monobasic, 2 g/L of sodium phosphate dibasic, and the final optimized medium was pH 6.10. When incubated in a 5 L jar fermenter, the SRCM101388 strain showed a faster-dissolved oxygen (DO) reduction at a lower agitation rate (rpm), and it was able to grow even at reduced DO level when aeration was maintained. The amount of final biomass produced was 2.53±0.12×10⁹ CFU/mL (9.40±0.02 log CFU/mL) when incubated for 18 hours at 150 rpm, 0.5 vvm, pH 6.0, and 28℃.

• Pediatric Infection and Vaccine
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• v.7 no.1
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• pp.136-142
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• 2000

Purpose : Although there are a lot of the reports about the persistence of anti HBs titer of plasma derives HBV vaccine, it is difficult to find the follow up studies of the recombinant HBV vaccine. We performed this study to compare the persistence of anti HBs titer by vaccination schedule and the seronegative rate of 5 years later according to Anti HBs titer after basic immunization in neonatal period by recombinant HBV vaccination. Methods : This study was performed on 420 neonates at Pusan Moon Hwa Hospital from April to December 1993, followed up for 5 years after basic immunization by recombinant HBV vaccine. The anti HBs titer test was done by radioimmunoassay(RIAAUSAB, Abbott laboratories). The positive anti HBs level that would protect against HBV infection was defined as a level equal to or greater than 10mIU/mL. Results : In this study the seronegative rate after 5 years was 5% in 2 month schedule group, 25.5% in 6 month schedule group(P>0.05). In 2 month schedule group the seronegative rate was 20% when anti HBs titer is lower than 200mIU/mL, 0% when more than 200mIU/mL(P>0.05). In 6 month schedule group the seronegative rate was 66.7% when anti HBs titer was lower than 200mIU/mL, 40% when 200~499.9mIU/mL, 23.9% when 500~999.9mIU/mL, 22.5% when more than 1000mIU/mL. Conclusion : In this study the seronegative rate after 5 years of recombinant HBV vaccination was 5~25.5%. The persistence of anti HBs titer was statistically irrelevant to schedule. The seronegative rate after 5 years was statistically irrelevant to anti HBs titer after basic immunization.

• Journal of Wetlands Research
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• v.17 no.4
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• pp.391-401
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• 2015

In this study, divided into small category groups for the residential area it was carried out monitoring for the runoff during precipitation. Based on the results analyzed according to the nonpoint sources Housing leakage characteristics. Analysis of the rainfall runoff and concentration of each type of exclusive detached house with apartments, in the majority of precipitation types runoff concentrations were higher in early. In the case of a difference of two points per runoff rate rainfall it was largely investigation. The average runoff is estimated loadings of BOD $101.1kg/km^2$, SS $232.2kg/km^2$, T-N $18.2kg/km^2$, T-P $2.0kg/km^2$ detached house case, if the apartment was estimated at point BOD $108.82kg/km^2$, SS $329.18kg/km^2$, T-N $57.67kg/km^2$, T-P $4.21kg/km^2$. The average EMCs is BOD BOD 6.6 mg/L, SS 12.8 mg/L, T-N 1.518 mg/L, T-P 0.099 mg/L detached house case, if the apartment was estimated at point BOD 6.3 mg/L, COD 11.2mg/L, SS 14.5 mg/L, T-N 3.1 mg/L, T-P 0.2 mg/L. The initial 30 percentage calculated based on the initial results, the total flow of 30% if the outflow of detached house showed a net percentage difference to T-P 1.04 > T-N 0.97 > BOD 0.90 > SS 0.80. The apartment area showed the percentage difference in the water quality in the order of BOD 1.49 > T-P 1.40 > SS 1.30 > T-N 0.96 per item.

• Journal of Plant Biotechnology
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• v.47 no.3
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• pp.242-247
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• 2020

This experiment was performed to determine the concentration of coconut water that is most effective in promoting the growth of 'Maehyang' strawberry in tissue culture. Cultivars in this experiment consisted of 'Maehyang' grown in the presence of 0, 20, 40, 60, 80, 100 ml·L^-1 of coconut water which was added to a medium mixed with BA 0.5 mg·L^-1 and IBA 0.1 mg·L^-1. Morphological variation tests and SSR detection with coconut water were conducted to determine variations in proliferation. The proliferation rate of 'Maehyang' strawberry improved with the coconut water treatment compared to non-treatment. In particular, the proliferation rate with 100 ml·L^-1 coconut water treatment increased by about 4 times. When 'Maeyang' was treated with 100 ml·L^-1 of coconut water, two morphological variants occurred without genetic variation. Therefore, the results suggest that 100 ml·L^-1 of coconut water can be used to mass-produce "Maeyang" strawberry without causing genetic variations.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.65-76
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• 2010

Purpose: he use of PET scanners and the number of patient in Korea have been increased for recent several years dramatically. For this reason, technologists have more possibilities to be exposed to the radiation. The hospitals using PET scanners should make an effort to reduce the radiation exposure dose. The purpose of this study was to evaluate the radiation exposure does when using radiation shielding devices. The evaluation was performed through questionnaire survey and experiment. Materials and Methods: First, the technologists who had experience working in PET center in 2008-2009 were surveyed with questionnaire and TLD Figures, personal opinion of utilization of radiation shielding devices are analyzed. Second, we measured the shielding rate of shielding devices which have been using in PET study procedures. We divided the procedures into four steps; distribution, moving, injection of $^{18}F$-FDG and patient setup. Results: First, the results of this survey, using of L-block+Syringe shield, L-block, Syringe shield, No shield during the injection, were each 58.5%, 20%, 9%, 12.3%. The TLD values according to utilization of radiation shield, using both L-block+Syringe Shield and L-block showed the lower TLD values, and Syringe shield only or No shield showed the higher TLD values. Second, the results of experiments according to PET study procedures measured the shielding rates as follows. The shielding rates during the distribution using L-block, L-block+Apron shield were measured 97.4%, 97.7%. The shielding rates during the $^{18}F$-FDG delivery to the injection room using mobile Syringe shield, Syringe holder, Syringe shield carrier were each 81.7%, 98.9%, 99.7%. The shielding rates during the injection using Syringe shield, L-block, L-block+Syringe shield were measured each 51.9%, 98.3%, 98.7%. The shielding rates of Apron were measured in each 30, 60, 90, 120, 150 cm distance. The measurement were each 16.9%, 14.2%, 16.6%, 17.1%, 18.1%, 18.6%. Conclusion: The most effective method for radiation shielding is to using L-block during the $^{18}F$-FDG distribution and Syringe shield carrier during in moving $^{18}F$-FDG. For the $^{18}F$-FDG injection, L-block+Syringe shield have to be used. The shielding effect of Apron has shown average 16.4%. According to the survey of questionnaire, the operators recognized well risk of the radiation exposure but, tended ignore in working. The radiation dose according to recognition of radiation exposure risk was not relevant. but radiation dose according to utilization of radiation shield lower the more use it. The main reason of no use of shielding devices is cumbersome, 55% of the respondents answered. I'm sure, by use of radiation shield in all PET procedure, radiation exposure will be reduced considerably.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.7
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• pp.495-502
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• 2013

This work was performed to investigate proper condition of coagulation treatment as UF process pretreatment that consider UF permeate flux and residual Al concentration. The coagulant used an alum as $Al_2(SO_4)_3{\cdot}16H_2O$ and PACl (r = 1.5) made this study. The experiment was tested in adjusting conditions such as alum dose, flocculation time and coagulation pH of seawater. Consequently, higher coagulant dose lead to elevation of UF permeate flux while residual aluminium also increased in condition of pH 8.0. The most suitable condition which has a good permeate flux and low residual aluminium, in this works, was coagulant dose of 0.7 mg/L (as Al, alum) and 1.2 mg/L (as Al, PACl) and coagulation pH 6.5. In addition, applying the flocculation time with 1.2 mg/L of PACI reduced. The flocculation time reduced UF permeate flux in using alum.

• Elastomers and Composites
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• v.49 no.1
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• pp.13-23
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• 2014

In this work, glycolide, L-lactide and ${\varepsilon}$-caprolactone monomers were polymerized into the triblock copolymers by two step polymerization method and their non-isothermal crystallization behaviors were studied by combination of modified Avrami and Ozawa formula for further analysis of their behaviors. The result showed that PGCLA21 gave the highest value for supercooling analysis and super cooling degree increased with L-lactide content. Crystallization velocity constant, however, showed no significant change. The result of cooling function in specific relative crystallization degree showed that the increase of L-lactide content made an effect on the more enhancement of crystallization velocity of the PGCLA than PGCL. The result of big logF(T) value with the L-lactide content above critical point for PGCLA41 and PGCLA21 showed that bigger cooling velocity needed to gain same crystal size compared with PGCL. This means that it gives negative effect in the increase of crystallization velocity.

• KSBB Journal
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• v.16 no.5
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• pp.474-479
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• 2001

Fed-batch culture, single stage and two stage continuous cultures of Corynebacterium glutamicum SH 35 for the production of $_{L}$-Iysine were performed and compared. In the case of fed batch culture, $_{L}$-Iysine concentration, $_{L}$-Iysine yield and $_{L}$-Iysine productivity was 129.2 g/L, 47.0% and 3.08 g/L/h, respectively. In a single-stage continuous culture, optimum dilution rate and pH was 0.1 h$^{-1}$ and 6.9, respectively, and optimum concentration of sugar and ammonium sulfate in a medium reservoir was 108 g/L and 25 g/L, respectively. Under the optimized conditions, 67 of cell concentration($OD_{610}$), 44.2 g/L of lysine concentration, 41% of $_{L}$-Iysine yield and 4.39 g$L^{-1}$ of $_{L}$-Iysine productivity were obtained. In a two-stage continuous culture, optimum dilution rate was 0.075 $h^{-1}$. Under the conditions, 103 of cell concentration($OD_{610}$) 84.0g/L of $_{L}$-Iysine concentration and 46% of $_{L}$-Iysine yield were obtained.

• Journal of Life Science
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• v.6 no.1
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• pp.6-13
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• 1996

The possible use of milk-wastewater as a fermentation media for the production of citric acid by Aspergillus niger has been investigated. The addition of Mn$^{2+}$ , Fe$^{2+}$ and Cu$^{2+}$ to the medium promoted citric acid production while only Mg$^{2+}$ decreased citric acid production. The concentrations of citric acid produced were marked up to 7.2g/l and 16.5g/l in a batch bioreactor by Aspergillus niger ATCC 9142 with 50g/l and 100g/l of reducing sugar concentration in milk-wastewater, respectively. A mathematical model was developed and simulating the predictability of cell growth, citric acid production and substrate consumption rate, and gave good agreement results with experimental data.

• Food Science of Animal Resources
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• v.24 no.2
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• pp.156-163
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• 2004

This study was carried out to investigate the improvement of stretchability in Mozzarella cheese based on the influence of various factors such as starter type, fat content, salt content and stretching temperature. To do this study, stretchability, meltability, fat leakage and the change of soluble nitrogen compound were measured during storage of the Mozzarella cheese at 4$^{\circ}C$ for 10 weeks. When L bulgaricus starter was added, stretchability of the cheese was excellent and cheese manufactured with starter of L bulgaricus and L. bulgaricus : Str. thermophilus = 1:2 improved meltability because of high soluble nitrogen compound. When salt content of cheese was 0.5％, this resulted in extreme deterioration of quality in regard to stretchability, meltability and fat leakage at five weeks and when salt content of cheese was 0.5, 1.0 and 1.5％, soluble nitrogen compound was 4.49, 4.45 and 2.61 ％ at one week and 19.71, 19.44％ and 17.07％ at eight weeks, respectively. Stretchability was good at high stretching temperature, and cheese with stretching at 60'C showed poor meltability at the first stage, but this cheese had good meltability in process of time because increase in soluble nitrogen compound was high at low stretching temperature.