• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.3
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• pp.142-154
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• 2011

This study predicted the probability of corrosion initiation of reinforced concrete tunnel boxes structures using the Monte Carlo Simulation. For the inner wall and outer wall in the tunnel boxes, exposed to airborne chloride ion and seawater directly respectively, statistical values of parameters like diffusion coefficient D, surface chloride content $C_s$, cover depth c, and the chloride threshold level $C_{lim}$ were examined from experiment or literature review. Their average values accounted for $3.77{\times}10^{-12}m^2/s$, 3.0% by weight of cement, 94.7mm and 45.5mm for outer wall and inner wall, respectively, and 0.69% by weight of cement for D, $C_s$, c, and $C_{lim}$, respectively. With these parametric values, the distribution of chloride contents at rebar with time and the probability of corrosion initiation of the tunnel boxes, inner wall and outer wall, was examined by considering time dependency of chloride transport. From the examination, the histogram of chloride contents at rebar is closer to a gamma distribution, and the mean value increases with time, while the coefficient of variance decreases with time. It was found that the probability of corrosion initiation and the time to corrosion were dependent on the time dependency of chloride transport. Time independent model predicted time to corrosion initiation of inner wall and outer wall as 8 and 12 years, respectively, while 178 and 283 years of time to corrosion was calculated by time dependent model for inner wall and outer wall, respectively. For time independent model, the probability of corrosion at 100 years of exposure for inner wall and outer wall was ranged 59.5 and 95.5%, respectively, while time dependent model indicated 2.9 and 0.2% of the probability corrosion, respectively. Finally, impact of $C_{lim}$, including values specified in current codes, on the probability of corrosion initiation and corrosion free life is discussed.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.187-197
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• 2010

Carbon dioxide Capture and Storage(CCS) is regarded as one of the most promising options to response climate change. CCS is a three-stage process consisting of the capture of carbon dioxide($CO_2$), the transport of $CO_2$ to a storage location, and the long term isolation of $CO_2$ from the atmosphere for the purpose of carbon emission mitigation. Up to now, process design for this $CO_2$ marine geological storage has been carried out mainly on pure $CO_2$. Unfortunately the $CO_2$ mixture captured from the power plants and steel making plants contains many impurities such as $N_2$, $O_2$, Ar, $H_2O$, $SO_2$, $H_2S$. A small amount of impurities can change the thermodynamic properties and then significantly affect the compression, purification, transport and injection processes. In order to design a reliable $CO_2$ marine geological storage system, it is necessary to analyze the impact of these impurities on the whole CCS process at initial design stage. The purpose of the present paper is to compare and analyse the relevant physical property models including BWRS, PR, PRBM, RKS and SRK equations of state, and NRTL-RK model which are crucial numerical process simulation tools. To evaluate the predictive accuracy of the equation of the state for $CO_2-SO_2$ mixture, we compared numerical calculation results with reference experimental data. In addition, optimum binary parameter to consider the interaction of $CO_2$ and $SO_2$ molecules was suggested based on the mean absolute percent error. In conclusion, we suggest the most reliable physical property model with optimized binary parameter in designing the $CO_2-SO_2$ mixture marine geological storage process.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.3
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• pp.217-226
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• 2009

Marine geological storage of $CO_2$ is regarded as one of the most promising options to response climate change. Marine geological storage of $CO_2$ is to capture $CO_2$ from major point sources, to transport to the storage sites and to store $CO_2$ into the marine geological structure such as deep sea saline aquifer. Up to now, process design for this $CO_2$ marine geological storage has been carried out mainly on pure $CO_2$. Unfortunately the captured $CO_2$ mixture contains many impurities such as $N_2$, $O_2$, Ar, $H_2O$, $SO_x$, $H_2S$. A small amount of impurities can change the thermodynamic properties and then significantly affect the compression, purification and transport processes. In order to design a reliable $CO_2$ marine geological storage system, it is necessary to perform numerical process simulation using thermodynamic equation of state. The purpose of the present paper is to compare and analyse the relevant equations of state including PR, PRBM, RKS and SRK equation of state for $CO_2-N_2$ mixture. To evaluate the predictive accuracy of the equation of the state, we compared numerical calculation results with reference experimental data. In addition, optimum binary parameter to consider the interaction of $CO_2$ and $N_2$ molecules was suggested based on the mean absolute percent error. In conclusion, we suggest the most reliable equation of state and relevant binary parameter in designing the $CO_2-N_2$ mixture marine geological storage process.

• Journal of Nutrition and Health
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• v.49 no.6
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• pp.437-446
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• 2016

Purpose: The purpose of this study was to estimate dietary intake of vitamin D and the relationship between serum 25-hydroxyvitamin D (25OHD) concentration and bone mineral density (BMD) in Korean adults using the 2011 data from the Korea National Health and Nutrition Examination Survey. Methods: Daily intake of vitamin D and ratio of subjects that consumed less vitamin D than adequate intake (AI) were estimated in 4,879 Korean adults. The relationship between daily intake of vitamin D and serum 25OHD and BMD were analyzed. Results: Average daily intakes of vitamin D were $3.84{\pm}0.23{\mu}g/day$ for men and $2.22{\pm}0.11{\mu}g/day$ for women. Approximately 72~97% of men and 80~99% of women consumed less than the AI of vitamin D for Koreans. Serum 25OHD concentration increased with age, and the ratios of serum vitamin D deficiency (< 20 ng/mL) were 47.8~81.1% for men and 59.4~92.8% for women. Average intake of vitamin D was higher in subjects aged < 50 yr than in those ${\geq}50yr$, but lower in serum 25OHD concentration. In subjects aged < 50 yr, serum 25OHD was higher in subjects that consumed $10{\mu}g/day$ of vitamin D than in those that consumed less than $5{\mu}g/day$. In female subjects aged ${\geq}50yr$, average intake of vitamin D was associated with higher bone mineral density. Conclusion: It was found that dietary intake of vitamin D could increase serum 25OHD concentration in young adults and bone mineral density in old women. Therefore, nutrition policies for enriched foods with vitamin D and nutrition education to consume more vitamin D-rich foods are needed to ameliorate vitamin D status of the Korean population. Adequate intake for Korean population aged < 50 yr might be adjusted upwardly up to $10{\mu}g/day$.

• Journal of Nutrition and Health
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• v.50 no.2
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• pp.192-200
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• 2017

Purpose: The purposes of this study were to analyze visitors' food needs and identify the Push-Pull factor in Jeonju Hanok Village. Methods: A questionnaire was developed based on previous research to survey Korean adults who visited Jeonju city. A total of 580 questionnaires were used for the analysis. Results: Most of the subjects who visited Jeonju Hanok Village had food purchase experiences in Jeonju Hanok Village (96.4%). 'Traditional Korean food (26.5%)' was the most purchased food, followed by 'foreign food (25.8%)' and 'Korean food combined with foreign food (16.8%)'. Satisfaction of food purchases (3.35 points) was higher than average. The primary reason for satisfaction was 'the food is delicious (23.0%)', and the reason for dissatisfaction was 'the food is expensive (48.1%)'. In the push and pull factor analysis for identifying visit motivation, 'local food seeking', 'experience seeking', 'relaxation seeking', and 'friendship seeking' were push factors while 'traditional culture', 'facility convenience', 'experience activity', and 'food experience' were pull factors. There was a significant correlation between the push and pull factors. Regression analysis showed that all push factors influenced satisfaction. However, among pull factors, only 'food experience' and 'traditional culture' influenced satisfaction. Conclusion: In conclusion, this study indicates that food-related factors are destination characteristics (Pull factor) influencing intrinsic visit motivation (Push factor) and satisfaction. It is necessary to develop various food tourism products to satisfy visitors' needs and continuous visits in Jeonju Hanok Village. This study suggests the importance of research on food factors and provides useful basic data to establish positioning strategies for food cultural development in Jeonju Hanok Village.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.447-452
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• 2007

This experiment was conducted to enhance the colored potatoes utilization and to determine the biological activity of colored potato extracts. In order to understand the factors responsible for the potent antioxidant and antihypertensive ability of colored potatoes, it has been evaluated for anti-oxidative activity using Fenton's reagent/ethyl linoleate system and for free radical scavenging activity using the 1,1-diphenyl-2-picryl hydrazyl free radical generating system. There were significant differences of antioxidant activities in $50{\mu}g/mL$ extracts treatment among different colored potatoes. About two-fold higher radical scavenging activity was found in 'Daegwan 1-102', 'Daegwan 1-104' and 'Jasim' compared to that in 'Superior'. Based on the flesh color tested, potatoes with purple tuber showed higher radical scavenging activity than red potatoes, while white potato showed the lowest radical scavenging activity. The ability of 80% ethanol extracts from colored potatoes to influence the inhibitory activity of angiotensin converting enzyme(ACE) and xanthine oxidase(XOase) has also been investigated. Expect 'Jasim', the high levels of inhibition activity of xanthine oxidase in two colored potatoes such as 'Daegwan 1-102' and 'Daegwan 1-104' were highly correlated to $IC_{50}$ values of ACE inhibition activity. The various therapeutic benefit claims in the new functional medicinal usage of colored potatoes ascribed to the phenolic compounds and anthocyanin. This result revealed that the extracts of colored potatoes are expected to be good candidate for development into source of free radical scavengers and anti-hypertentive agent.

• Development and Reproduction
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• v.5 no.1
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• pp.23-33
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• 2001

When mammalian oocytes ovulate into the oviduct, associating follicular fluid components are exposed to the oviductal environment, possibly resulting in the mutual interaction between fillicu1ar and oviductal fluids. In the Present study, we have demonstrated for the first time that components of fallicular fluid could be modified by the oviductal fluid. Gelatin zymographic analyses of human follicular fluid (hFF) obtained from IVF patients showed consistently the presence of 110 kDa gelatinase (GA110) in addition to many bands among which 62 kDa gelatinase was predominant. Addition of EDTA or phenanfhroline to the gelatinase substrate buffer during gel incubation abolished GA110 band whereas phenylmethylsulffnyl fluoride (PMSF) did not. In contrast, bovine oviductal fluid(bOF) exhibited only 62 kDa gelatinase. Surprisingly, when bOF was added to hFF in 1:1 ratio and then the mixture was incubated for 3 h at 37$^{\circ}$C, GA110 of hFF disappeared. Disappearance of GA110 by bOF was observed even within 30 min after mixing with hFF. Addition of aminophenylmercuric acetate (APMA) to hFF also abolished enzymatic activity of GA110 but increased the activityof 62 kDa gelatinase. However, APMA abolished many other gelatinases as well unlike bOF. Interestingly, treatment of hFF with EDTA for 3 h remarkably increased the enzymatic activity of GA110 but not that of other gelatinases. Addition of phenanthroline, PMSF or soybean trypsin inhibitor (SBTI) did not affect overall gelatinase activities. Again, addition of bOF to the hFF pretreated with any of the above proteinase inhibitors abolished the appearance of GA110. Human serum also showed GAI 10 of which activity was greatlyenhanced by EDTA treatment. Similar to hFF, serum GA110 also disappeared by the addition of bOF. Human granulosa cell homogenate did not reveal any appreciable gelatinase activity except 92 kDa gelatinase. Anti-human gelatinase A antibody reacted with 62 kDa gelatinase of hFF. Based upon these results, it is concluded that bOF could selectively degrade an isoform of gelatinase A present in hFF and human serum.

• Economic and Environmental Geology
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• v.36 no.4
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• pp.305-312
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• 2003

This study was performed to delineate the subsurface geology, geologic structure, and distribution pattern of the Palgongsan granitic body, and to reveal the relationship between the Kyeongsang basin and Yongnam massif by gravity survey. The study area is located between the latitude of 35$^{\circ}$45'-36$^{\circ}$21'N and longitude of 128$^{\circ}$15'-129$^{\circ}$00'E. Total of 966 gravity data measured by Seoul National University, KlGAM(Korea Institute of Geology, Mining ＆ Materials), Pusan National University and Yonsei University were used. The Bouguer gravity anomaly in the study area ranges from -12.88 to 26.01 mgal with a mean value of 11.27 mgal. A very low anomaly zone is located in the Yongnam massif in west of the study area. The anomaly value increases going from west to east. A low anomaly distribution in Palgongsan granite and Yongnam massif is interpreted as the effect of their lower density than that of Kyeongsang Super Group. Power spectrum analysis is applied to evaluate the average depth of basement the Kyeongsang Basin and Conrad discontinuity from gravity anomaly. The average depths of density discontinuities are calculated 10.45 km and 4.9 km, and these are interpreted as Conrad discontinuity and depth of basement of the Kyeongsang Basin, respectively. The depth of Palgongsan granite is derived by means of 2-dimensional modeling and it decreases gradually toward the east. The gravity anomaly east of the study area decreases abruptly due to Shingryeong fault and Nogosan ring fault. Two deepest and sharp roots of Palgongsan granite are recognized by 2-dimensional modeling of each profiles. The depths of those roots are 5.3 km on a profile AA' and 7 km on a profile BB' which is the maximum depth of Palgongsan granite. Small granitic bodies are also seen to be intruded around the Palgongsan granite. The root of Palgongsan granite is shown by 3-dimensional analysis based on the interpolation of 2-dimensional modeling along each profiles to exist in the southwest vicinity of Palgongsan granite. The total volume of Palgongsan granite is approximately 31.211 $Km^3$.

• Economic and Environmental Geology
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• v.50 no.6
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• pp.445-466
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• 2017

Yeongdong area is located in the contact zone between central southeastern Ogcheon belt and Yeongnam massif, in which Cretaceous Yeongdong basin exists. Therefore, the study area has complex geological environment of various geological age and rock types such as Precambrian metamorphic rocks, age-unknown Ogcheon Supergroup, Paleozoic/Mesozoic sedimentary rocks, Mesozoic igneous rocks and Quaternary alluvial deposits. This study focuses on the link between the various geology and water type, and discussed the source of some major ions and their related water-rock interaction. For this study, the field parameters and ion concentrations for twenty alluvial/weathered and eighty bedrock aquifer wells were used. Statistical analysis indicates that there was no significant differences in groundwater quality between wet and dry seasons. Although various types were observed due to complex geology, 80 to 84 % of samples showed $Ca-HCO_3$ water type. Some wells placed in alluvial/weathered aquifers of Precambrian metamorphic and Jurassic granitic terrains showed somewhat elevated $NO_3$ and Cl concentrations. $Mg-HCO_3$ typed waters prevailed in Cretaceous Yeongdong sedimentary rocks. The deeper wells placed in bedrock aquifers showed complicated water types varying from $Ca-HCO_3$ through $Ca-Cl/SO_4/NO_3$ to $Na-HCO_3$ and Na-Cl type. Groundwater samples with $Na-HCO_3$ or Na-Cl types are generally high in F concentrations, indicating more influences of water-rock interaction within mineralized/hydrothermal alteration zone by Cretaceous porphyry or granites. This study revealed that many deep-seated aquifer had been contaminated by $NO_3$, especially prominent in Jurassic granites area. Based on molar ratios of $HCO_3/Ca$, $HCO_3/Na$, Na/Si, it can be inferred that Ca and $HCO_3$ components of most groundwater in alluvial/weathered aquifer wells were definitely related with dissolution of calcite. On the other hand, Ca and $HCO_3$ in bedrock aquifer seem to be due to dissolution of feldspar besides calcite. However, these molar ratios require other mechanism except simple weathering process causing feldspar to be broken into kaolinite. The origin of $HCO_3$ of some groundwater occurring in Cretaceous Yeongdong sedimentary rock area seems to be from dissolution of dolomite($MgCO_3$) or strontianite($SrCO_3$) as well.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.238-249
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• 2019

The evapotranspiration is estimated based on weather factors such as temperature, wind speed and humidity, and the Hargreaves equation is a simple equation for calculating evapotranspiration using temperature data. However, the Hargreaves equation tends to be underestimated in areas with wind speeds above 3 m s^-1 and overestimated in areas with high relative humidity. The study was conducted to determine Hargreaves equation coefficient in 82 regions in Korea by comparing evapotranspiration determined by modified Hargreaves equation and the Penman-Monteith equation for the time period of 2008~2018. The modified Hargreaves coefficients for 50 inland areas were estimated to be 0.00173~0.00232(average 0.00196), which is similar to or lower than the default value 0.0023. On the other hand, there are 32 coastal areas, and the modified coefficients ranged from 0.00185 to 0.00303(average 0.00234). The east coastal area was estimated to be similar to or higher than the default value, while the west and south coastal areas showed large deviations by area. As results of estimating the evapotranspiration by the modified Hargreaves coefficient, root mean square error(RMSE) is reduced from 0.634~1.394(average 0.857) to 0.466~1.328(average 0.701), and Nash-Sutcliffe Coefficient(NSC) increased from -0.159~0.837(average 0.647) to -0.053~0.910(average 0.755) compared with original Hargreaves equation. Therefore, we confirmed that the Hargreaves equation can be overestimated or underestimated compared to the Penman-Monteith equation, and expected that it will be able to calculate the high accuracy evapotranspiration using the modified Hargreaves equation. This study will contribute to water resources planning, irrigation schedule, and environmental management.