• Journal of Ocean Engineering and Technology
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• v.32 no.6
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• pp.419-426
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• 2018

Recently, in an effort to reduce the energy efficiency design index (EEDI), studies on energy saving devices (ESDs) have been conducted. In this study, we designed a post-device suitable for a KRISO container ship (KCS) using computational fluid dynamics (CFD). In order to increase the efficiency of the post-device, a twisted rudder was used, which has a proven performance (showing a 1.34% reduction in DHP compared to the bare hull at 24 knots) in previous research at Pusan National University. In addition, an increase in efficiency was expected by the use of a rudder bulb, including the discontinuous section of the twisted rudder and a divergent propeller cap to prevent the contraction of the wake. The optimization criterion was the case where the delivery power was the least compared with the bare hull. We analyzed the cause of the efficiency increase through an analysis of the self-propulsion factor. The case study for optimization was divided into 4 types (1. clearance of the bulb and cap, 2. shape of the bulb, 3. size of the bulb and cap, and 4. asymmetric bulb). Finally, with a clearance of 50 mm from the ship, a spherical bulb with the cap having an angle of $5^{\circ}$, and an asymmetric rudder bulb with a bulb diameter of 1.2HH/1.4H (horizontal/vertical) showed a 2.05% reduction in DHP compared to the bare hull at 24 knots. We will fabricate a post-device that will be optimized in the future and verify the performance of the post-device through model tests.

• Economic and Environmental Geology
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• v.52 no.2
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• pp.141-158
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• 2019

The quantity of heavy metals in agricultural surface and subsurface soils around coal-fired power plants located in Samcheonpo and Hadong, Gyeongnam Province, were determined. The analytical results for 48 and 61 soils in Samcheonpo and Hadong, respectively, showed that the concentrations of Cu, Hg, Ni, Pb, and Zn were below the warning criteria regulated by Korean Soil Conservation Act; however, Cd in 38 and 13 soils in Samcheonpo and Hadong, respectively, exceeded the criterion. As a result of calculation of the geoaccumulation index and the enrichment factor, the soils were extremely contaminated with Cd and such high loading of Cd to the soils was due to anthropogenic source(s). Sequential extraction of the soils, however, showed that heavy metals including Cd existed as hardly extractable phases, which represented a low bioavailability of the heavy metals. Our results indicated that Cd contamination around the coal-fired power plants was due to artificial source(s) and may unlikely deteriorate nearby ecosystems.

• Nutrition Research and Practice
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• v.13 no.1
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• pp.32-40
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• 2019

BACKGOUND/OBJECTIVES: This study investigated nutritional status of the elderly with dementia in a care facility with the aim of improving the meal quality of the facility. SUBJECTS/METHODS: Data were collected from 30 dementia patients aged more than 65 years in a long-term care facility in Hongseong. The data were obtained from questionnaires and medical records. The food intake data was obtained using food photographs and the nutrient intakes were calculated using the CAN-Pro 5.0. The data were compared with the dietary reference intakes for Koreans (KDRIs). The nutrient density, diet quality such as nutrient adequacy ratio (NAR), mean adequacy ratio (MAR), and index of nutritional quality (INQ), as well as dietary diversity score (DDS) were evaluated. The data were analyzed using SPSS statistical programs. RESULTS: The average daily energy intakes for men and women were much lower than the estimated energy requirements of the KDRIs. The average intakes of energy and most nutrients in the general diet group were significantly higher than those of the other two groups. Significant differences in diet quality and diet diversity were observed according to the meal type groups. The NARs of some minerals (calcium, iron, and zinc) and vitamins (vitamin $B_6$ and folic acid) were less than 0.5 in all study groups. The NARs of protein, iron and MAR of the general diet group were significantly higher than those of the liquid diet group. The DDS scores of meats, fruits and diary food group were very low in all meal type groups, meaning that the diet qualities of the study subjects were not appropriate in all meal type groups. CONCLUSIONS: The food intakes of the study groups showed some limitations by a direct comparison with KDRIs because of the very low physical activities of the study subjects. The diet quality and diet diversity indices suggest the need for improvements in the nutritional quality in all types of diet. Overall, new intervention strategies targeting facility residents with dementia in Korea are needed as soon as possible.

• Journal of Korean Society on Water Environment
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• v.35 no.3
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• pp.201-208
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• 2019

In this study, we analyzed composition of the bioflocculant, which strain YG-02 produces. First, supernatant and suspension from centrifugation of culture fluid of the strain, were used in the flocculation experiment. As a result, the SVI(sludge volume index) added with the suspension, was 182 mL/g, same as the control group with no additive, and the SVI added with supernatant, was 164 mL/g. So, the result above showed that flocculation capacity of the bioflocculant, was dependent on the substance which strain YG-02 produces, not on factors such as the body of germs. As a result of the thermostability test on substances that cause flocculation, the flocculation effect was significantly reduced, compared to the result of the flocculation test, before applying heat to the culture fluid, and it was able to assume that the substance that causes flocculation, was damaged by heat. Additionally, to understand the component of the bioflocculant, analyzation of sugar composition and fatty acid, was conducted. As a result, sugar composition was the polysaccharide consisting of glucose: lactose with molar ratio of 90.75:9.25. Fatty acid content was detected, as 0.0012 g/100g, showing that it contained glycolipid in the bioflocculant. Such results show that the bioflocculant which strain YG-02 produces, is the new bioflocculant, different from bioflocculantstudiedto date.

• Journal of Microbiology and Biotechnology
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• v.32 no.7
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• pp.835-843
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• 2022

Deinococcus radiodurans is an extremophilic bacterium that can thrive in harsh environments. This property can be attributed to its unique metabolites that possess strong antioxidants and other pharmacological properties. To determine the potential of D. radiodurans R1 lysate (DeinoLys) as a pharmacological candidate for inflammatory bowel disease (IBD), we investigated the antiinflammatory activity of DeinoLys in bone marrow-derived dendritic cells (BMDCs) and a colitis mice model. Lipopolysaccharide (LPS)-stimulated BMDCs treated with DeinoLys exhibited alterations in their phenotypic and functional properties by changing into tolerogenic DCs, including strongly inhibited proinflammatory cytokines (TNF-α and IL-12p70) and surface molecule expression and activated DC-induced T cell proliferation/activation with high IL-10 production. These phenotypic and functional changes in BMDCs induced by DeinoLys in the presence of LPS were abrogated by IL-10 neutralization. Furthermore, oral administration of DeinoLys significantly reduced clinical symptoms against dextran sulfate sodium-induced colitis, including body weight loss, disease activity index, histological severity in colon tissue, and lower myeloperoxidase level in mice. Our results establish DeinoLys as a potential anti-inflammatory candidate for IBD therapy.

• Korean Journal of Exercise Nutrition
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• v.23 no.2
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• pp.22-27
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• 2019

[Purpose] The purpose of this study was to compare the excess post-exercise oxygen consumption (EPOC) between different types of exercises in women with normal weight obesity (NWO). [Methods] Nine university students with NWO having body mass index <25 kg/m² and body fat percentage >30% participated in the study. First, continuous exercise (CEx) on an ergometer for 30 minutes at 60% of maximal oxygen consumption (VO_2max) and interval exercise (IEx) at 80% VO_2max for 2 minutes were performed. This was followed by exercise performed at 40% VO_2max for 1 minute and at 80% VO_2max for 3 minutes, performed 6 times repeatedly for a total of 26 minutes. The accumulation of short duration exercise (AEx) was performed for 3-bouts of 10 minutes each at 60% VO_2max. [Results] The major findings were as follows: energy consumption during the exercises showed no significant difference between CEx, IEx, and AEx; EPOC was higher in IEx and AEx as compared to CEx for all dependent variables (e.g. total oxygen consumption, total calorie, summation of heart rate, and EPOC duration); and the lipid profile showed no significant difference. [Conclusions] Our study confirmed that when homogenizing the energy expenditure for various exercises in NWO individuals, EPOC was higher in IEx and AEx than in CEx. Therefore, IEx and AEx can be considered as effective exercise methods for increasing energy expenditure in NWO females.

• Journal of Soil and Groundwater Environment
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• v.27 no.6
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• pp.47-57
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• 2022

A number of different methods have been used for modeling the sorption of volatile organic chlorinated compounds such as tetrachloroethylene/perchloroethylene (PCE). In this study, PCE was adsorbed in several natural sorbents, i.e., Pahokee peat, vermicompost, BionSoil^®, and natural soil, in the batch experiments. Several sorption models such as linear, Freundlich, solubility-normalized Freundlich model, and Polanyi-Manes model (PMM) were used to analyze sorption isotherms. The relationship between sorption model parameters, organic carbon content (f_oc), and elemental C/N ratio was studied. The organic carbon normalized partition coefficient values (log K_oc = 1.50-3.13) in four different sorbents were less than the logarithm of the octanol-water partition coefficient (log K_ow = 3.40) of PCE due to high organic carbon contents. The log K_oc decreased linearly with log f_oc and log C/N ratio, but increased linearly with log O/C, log H/C, and log (N+O)/C ratio. Both log K_F,oc or log K_F,oc decreased linearly with log f_oc (R² = 0.88-0.92) and log C/N ratio (R² = 0.57-0.76), but increased linearly with log (N+O)/C (R² = 0.93-0.95). The log q_max,oc decreased linearly as log f_oc and log C/N increased, whereas it increased with log O/C, log H/C and log (N+O)/C ratios. The log q_max,oc increased linearly with (N+O)/C indicating a strong dependence of q_max,oc on the polarity index. The results showed that PCE sorption behaviors were strongly correlated with the physicochemical properties of soil organic matter (SOM).

• Journal of the Korean Dietetic Association
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• v.29 no.2
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• pp.73-85
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• 2023

This study examined the nutritional information using the nutrition labels of gimbap sold at convenience stores and evaluated nutritional adequacy compared to dietary reference intakes for Korean adolescents. Thirty gimbaps (triangular gimbaps and regular gimbaps according to the main ingredients of vegetables, fish, and meat) were purchased at five convenience stores of different brands with many stores in Korea. The food and nutrition labels of the gimbaps were investigated, and nine minerals were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS). The average price of gimbap was 1,906.7 won, and average energy was 292.0 kcal, and the protein content was 15.5% of the recommended intake for Korean male adolescents aged 15~18 years. The mineral content ranged from 6.9% for zinc to 39.0% for selenium. Except for sodium and selenium, the energy, protein, and mineral content did not meet 1/3 of dietary reference intakes for adolescents. For the index of nutritional quality (INQ), calcium and zinc were the lowest in the triangular and regular gimbap, respectively. The INQ of potassium was significantly higher in triangular gimbap with vegetables. The content and INQ of selenium were in regular gimbap with fish, and the zinc INQ was in regular gimbap with meat. Overall, gimbap sold in convenience stores has a high sodium content, and the contents of energy, protein, and minerals, except selenium, are insufficient for a single meal.

• Convergence Security Journal
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• v.22 no.2
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• pp.99-104
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• 2022

This study provided a prediction model for solar energy production in Yeongam province, Jeollanam-do. The model was derived from the correlation between climate changes and solar power production in Yeongam province, Jeollanam-do, and presented a prediction of solar power generation through the regression analysis of 6 parameters related to weather and solar power generation. The data used in this study were the weather and photovoltaic production data from January in 2016 to December in 2019 provided by public data. Based on the data, the machine learning technique was used to analyzed the correlation between weather change and solar energy production and derived to the prediction model. The model showed that the photovoltaic production can be categorized by the three-stage production index and will be used as an important barometer in the agriculture activity and the use of photovoltaic electricity.

• Journal of Soil and Groundwater Environment
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• v.28 no.6
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• pp.33-44
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• 2023

A risk assessment on the heavy metals including arsenic (As), cupper (Cu), lead (Pb), and zinc (Zn) was investigated by setting exposure routes in agricultural fields. Moreover, the factors requiring improvement in risk assessment were also discussed through a review of the dermal absorption slope factor (SF_abs) and total amount of suspended particles (TSP) in the current risk assessment guidelines. Assessment results show that the total cancer risk (TCR) of As through crop and soil ingestion was 1.51E-03 in adults and 6.37E-4 in children, which indicated a carcinogenic risk (exceeding 1E-05). On the other side, the harzard index (HI) was 3.37 in adults and 1.41 in children, which was evaluated as having a non-carcinogenic risk (>1). The carcinogenic purification targets for As were calculated to be 6.84 mg/kg in adults and 6.86 mg/kg in children, while the non-carcinogenic purification targets were calculated to be 13.43 mg/kg for adults and 22.54 mg/kg for children. When applying SF_abs 61 of the current guidelines, it appears that there is a carcinogenic risk even though the As exposure concentration is below the area of concern 1 standard (25 mg/kg), which suggestes that additional research on this factor is required for the risk assessment. In order to apply the measured suspended particle concentration to risk assessment, TSP should be derived from PM10 using an appropriate correlation equation. As a result, it is suggested to improve the risk assessment guidelines so that the mesured PM10 value measured in the field can be used directly.