• Food Science and Preservation
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• v.20 no.2
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• pp.191-198
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• 2013

In this study, wheat doenjang was manufactured using Korean wheat meju and soybean meju, and its quality were investigated according to mixing ratio of meju. The general characteristics such as moisture contents, pH and salinity of wheat doenjang, which is fermented and aged at $25^{\circ}C$ for 70 days, were slightly decreased time dependently as similar pattern. The pH of wheat doenjang ranged from 4.95 to 5.11% and generally decreased with aging. The moisture contents was 54.5~57.5%, and there was no significant differences in the aging period. Also, there was no significant changes in the salt contents. The amino-type nitrogen contents were 376.27~600.91 mg% at day 70 of the aging period, and showed 3 fold change compared to the initial contents. The reducing sugar contents showed significant difference between the samples, and repeated fluctuation in the aging period. Wheat meju sample A, which contains 50% of soybean meju, showed the highest antioxidation ability. In addition, wheat meju sample A showed the highest score in the sensory evaluation of the colour, taste, flavor, and overall acceptability. Therefore, wheat doenjang manufacturing at a 1:1 of mixing ratio will lead to desirable quality of wheat doenjang.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.483-490
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• 2009

The aims of this study were to evaluate the removal efficiency for various pollutants in urban storm runoff by a filtration device, and to determine design parameters depending on filter media properties. Appropriate selection of filter media will affect the size and life time of the filtration device. Sets of column tests were performed in order to evaluate the removal efficiency by perlite and a synthetic resin. An investigation of surface properties including CEC (cation exchange capacity) and zeta-potential suggested that the perlite had a superior adsorption capability for cationic pollutants. TCODcr and turbidity were analyzed to investigate the removal characteristic of particulate pollutant. In both columns, the particles in the collected storm runoff was almost completely capture with a small EBCT (empty bed contact time) of 2.5 minutes. Complete clogging at the EBCT of 2.5 minutes occurred after 630 minutes in the perlite column and 810 minutes in the resin column. The removal efficiency of TCODcr and turbidity at the EBCT of 2.5 minutes decreased to below 70% due to an wall effect. The removal efficiency for dissolved pollutant (SCODcr) was negligible due to the insufficient contact time for adsorption. The removal of heavy metals (Cu, Zn, Pb) was mostly ascribed to the filtration of particles containing metals, since the relationship between CEC and the removal efficiency was not apparent. The result of this study would be valuable for the application of filtration device to control of urban storm runoff.

• Journal of the Korean GEO-environmental Society
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• v.22 no.10
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• pp.21-29
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• 2021

Most concrete gravity-type dams in and out of the country were constructed by column method to control cracks caused by concrete hydration heat generated during construction, resulting in a certain level of leakage after impoundment through various causes, such as contraction joints and construction joints. However, due to the characteristics of concrete structures that shrink and expand according to temperature, concrete dams have vertical joints and drains to allow penetration. PVC waterproof shows excellent effects in completion of the dam, which however increases the possibility of interfacial failure due to different thermal expansion. Other causes of penetration may include problems with quality control during installation, generation of cracks due to heat of hydration of concrete, waterproofing methods, etc. In the case of Bohyunsan Dam in Yeongcheon, North Gyeongsang Province, the amount of drainage in the gallery was checked and underwater, and it was confirmed that there are many penetrations from drainage holes connected to vertical joints, and that some of the PVC waterproofs are not fully operated. As a new method to prevent penetration through vertical joints, D.S.I.M. (Dam Sealing Innovation Method) developed by World E&C was applied to Bohyunsan Dam and checked the amount of drainage in the gallery. As a result of first testing three most leaking vertical joints, the drain in the gallery was reduced by 87% on the average and then applied to the remaining 13 locations, which showed a 83% reduction effect based on the total drain in the gallery. Summing up these results, it was found that D.S.I.M. preventing water leakage from the upstream face is a valid construction method to reduce the water see-through and penetration quantity seen in downstream faces of concrete dams. If D.S.I.M. is applied to other concrete dams at domestic and abroad, it is expected that it will be very effective to prevent water leakage through vertical joints that are visible from downstream faces.

• Food Science and Preservation
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• v.30 no.6
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• pp.1056-1071
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• 2023

This study aimed to investigate the quality and microbial population changes for 90 days under two fermentation conditions, outdoors and indoors (35℃), with starters (single or mixed) in soybean paste. Bacillus velezensis NY12-2 (S1), Debaryomyces hansenii D5-P5 (S2), Enterococcus faecium N78-11 (S3), and their mixtures (M) were used for the makjang fermentation. The content of amino-type nitrogen among the makjang samples was highly shown in the indoors, followed by M, S3, and S2. The glutamic and aspartic acid contents in the M sample fermented in the indoors showed the highest values of 867.42±77.27 and 243.20±15.79 mg/g, respectively. By the electronic tongue analysis, the M sample fermented in the indoors exhibited lower saltiness and higher umami than the others. Consequently, we expect that using mixed strains, such as Bacillus, Debaryomyces, and Enterococcus, under constant conditions showed potential to the quality improvement of soy products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.2
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• pp.116-121
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• 1983

A study was conducted to evaluate the effect of $^{60}CO-{\gamma}$ irradiation on the preservation on Satauma mandarin in Cheju Island. Four varieties (S. m. early, S. m. Komezawa, S. m. Hayashi and S. m. Aoshima) were irradiated using 10,000Ci, $^{60}CO-{\gamma}$ ray with dosages of 0, 50, 100 and 150Krad. During 92 days of storage the effects of irradiation on mandarin porperties were as follows: At the end of storage period the accumulated fruit rotting percentage were S. m. Komezawa($T_2$);74.32%, S. m. early($T_1$);69.67%, S. m. Aoshima($T_4$);64.33% and S. m. Hayashi ($T_3$);61.79%. The rottings steadily increased from the early stage of storage and rapid spoilage continued after 59 days of irradiation. A high corelation existed between fruit rotting and varieties ($T_3$;Y=0.78x-15.30, $T_4$;Y=0.79x-12.29, $T_1$;Y=0.93x-9.01 and $T_2$;Y=0.79x-13.49) High dosages(100 and 150 Krad)improved fruit preservation during the mid storage stage. However 76 days after high dose irradiation there was no significant difference a rotting between irradiated fruit and the control. Irradiation decreased acidity of fruit during storage (p<0.01). The mean acidities of examined varieties were $T_1$;1.01%, $T_3$;1.01%, $T_4$;0.84% and $T_2$;0.77%. A significant differences were observed in acidity between varieties and dosages(P<0.01) With one exception in all treatments. the increase in free and total sugar content was not statestically significant. The exception was the 50 Krad treatment where the total sugar content decreased. $T_1$ and $T_4$ showed slightly higher value of than Brix $T_2$ and $T_3$, and were significantly(P<0.01) decreased by higher dosage. The ascorbic acid content in all treatments decreased with length of storage and also decreased significantly with a higher dosage.