• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.2
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• pp.102-114
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• 2013

The basin of Lake Shihwa is one of highly industrialized region of Korea and a current environmental issue of study area is the operation of tidal power plant (TPP) to improve water quality. The application of water quality index (WQI) which integrates five physiochemical parameters (transparency, DO, DIN, DIP and chlorophyll-a) of water quality in Lake Shihwa and outer sea during 2011~2012 were performed not only to evaluate the spatial and temporal distribution of the water quality but also to assess the effect of water quality improvement by the operation of tidal power plant. The higher WQI values were observed in monitored sites near the industrial complexes in Lake Shihwa and the outfall of wastewater treatment plants (WWTPs) in outer sea. This indicates that the quality of seawater is influenced by diffuse non-point sources from industrial, municipal and agricultural areas in Lake Shihwa and by point sources from the effluence of municipal and industrial wastewater throughout WWTPs in outer sea. Mean WQI value decreased from 53.0 in 2011 to 42.8 in 2012 of Lake Shihwa. Water quality has improved significantly after TPP operation because enhancement of seawater exchange between Lake Shihwa and outer sea leads to improve a hypoxic condition which is primarily a problem in Lake Shihwa. Mean WQI of outer sea showed similar values between 2011 and 2012. However, the results of hierarchical cluster analysis and the deterioration of water quality in summer season indicate that the operation of tidal power plant was not improved the water quality in the upper most area of Lake Shihwa. To successfully improve overall water quality of Lake Shihwa, it is urgently necessary to manage and reduce of non-point pollution sources of the basin of Lake Shihwa.

• Economic and Environmental Geology
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• v.49 no.5
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• pp.371-380
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• 2016

This study aims to identify the mineraloical and petrographical characteristics of caprock from drilling cores of Pohang basin as a potential $CO_2$ storage site. Experiments and modeling were conducted in order to investigate the geochemical and mineralogical caprock effects of carbon dioxide. A series of autoclave experiments were conducted to simulate the interaction in the $scCO_2$-caprock-brine using a high pressure and temperature cell at $50^{\circ}C$ and 100 bar. Geochemical and mineralogical alterations after 15 days of $scCO_2$-caprock-brine sample reactions were quantitatively examined by XRD, XRF, ICP-OES investigation. Results of mineralogical studies, together with petrographic data of caprock and data on the physicochemical parameters of brine were used for geochemical modeling. Modelling was carried out using the The Geochemist's Workbench 11.0.4 geochemical simulator. Results from XRD analysis for caprock sample showed that major compositional minerals are quartz, plagioclase, and K-feldspar, and muscovite, pyrite, siderite, calcite, kaolinite and montnorillonite were included on a small scale. Results from ICP-OES analysis for brine showed that concentration of $Ca^{2+}$, $Na^+$, $K^+$ and $Mg^{2+}$ increased due to dissolution of plagioclase, K-feldspar and muscovite. Results of modeling for the period of 100 years showed that the recrystallization of kaolinite, dawsonite and beidellite, at the expense of plagioclase and K-feldspar is characteristic. Volumes of newly precipitation minerals and minerals passing into brine were balanced, so the porosity remained nearly unchanged. Experimental and modeling results indicate the interaction between caprock and $scCO_2$ during geologic carbon sequestration can exert significant impacts in brine pH and solubility/stability of minerals.

• Korean Journal of Food Science and Technology
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• v.27 no.2
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• pp.156-163
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• 1995

The practical shelf-life of pasteurized Korean rice wine ‘Yakju’, aseptically packed in Tetra-pak, was determined. The test sample products were stored at $4^{\circ}C,\;20^{\circ}C,\;30^{\circ}C\;and\;35^{\circ}C$ for 19 weeks, and the quality assessment was made at two weeks interval. The quality parameters evaluated were pH, acidity, reducing sugar, absorbance at 370 nm, total and acid producing bacteria, yeast and mold, and sensory quality. No meaningful changes of pH and reducing sugar were noticed during the storage for 19 weeks at temperatures tested. The absorbance at 370 nm increased slightly during storage. The total numbers of microorganisms in the product decreased during storage and a drastical reduction of acid producing bacteria was observed after 6 weeks of storage. Both yeast and mold were not found in the pasteurized products. The sensory quality of stored rice-wine was evaluated by triangle test and scoring test. The panels could distinguish the product stored at $4^{\circ}C$ from other products stored at the higher temperatures for over 6 weeks. The overall acceptance of the product decreased gradually during storage, and the rate constants for the changes were $7.93{\times}10^{-3},\;at\;20^{\circ}C,\;9.69{\times}10^{-3}\;at\;30^{\circ}C\;and\;13.4{\times}10^{-3}\;at\;35^{\circ}C$, respectively. The activation energy estimated by Arrhenius equation was 24,795 kJ/kmol. The estimated shelf-life of Yakju pasteurized and aseptically packed was 24 months at $10^{\circ}C$, 16 months at $25^{\circ}C$ and 14 months at $25^{\circ}C$. The shelf-life of Yakju in Seoul was calculated to be 20 months, based on the monthly average temperature of the city.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.165-173
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• 2010

A cloud detection method is introduced to improve the reliability of NOAA/AVHRR Sea Surface Temperature (SST) data processed during the daytime and nighttime in the TeraScan System. In daytime, the channels 2 and 4 are used to detect a cloud using the three tests, which are spatial uniformity tests of brightness temperature (infrared channel 4) and channel 2 albedo, and reflectivity threshold test for visible channel 2. Meanwhile, the nighttime cloud detection tests are performed by using the channels 3 and 4, because the channel 2 data are not available in nighttime. This process include the dual channel brightness temperature difference (ch3 - ch4) and infrared channel brightness temperature threshold tests. For a comparison of daytime and nighttime SST images, two data used here are obtained at 0:28 (UTC) and 21:00 (UTC) on May 13, 2009. 6 parameters was tested to understand the factors that affect a cloud masking in and around Korean Peninsula. In daytime, the thresholds for ch2_max cover a range 3 through 8, and ch4_delta and ch2_delta are fixed on 5 and 2, respectively. In nighttime, the threshold range of ch3_minus_ch4 is from -1 to 0, and ch4_delta and min_ch4_temp have the fixed thresholds with 3.5 and 0, respectively. It is acceptable that the resulted images represent a reliability of SST according to the change of cloud masking area by each level. In the future, the accuracy of SST will be verified, and an assimilation method for SST data should be tested for a reliability improvement considering an atmospheric characteristic of research area around Korean Peninsula.

• Journal of Nutrition and Health
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• v.41 no.2
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• pp.147-155
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• 2008

Medical nutrition therapy (MNT) is considered a keystone of medical treatment of chronic diseases. However, only few studies have evaluated medical and economical outcome of MNT. The study was performed on the patient with type 2 diabetes mellitus to evaluate the effect of clinical and cost-effective outcomes of MNT. Subjects from two general hospitals were randomly assigned to two different groups; One receiving basic nutritional education (BE) (n = 35), and the other receiving intensive nutritional education (IE) (n = 32) for a 6-month clinical trial. The group which received BE had a single visit with a dietitian, while the other group which received IE had an initial visit with a dietitian addition to two visits during the first 4 weeks of the study periods. Anthropometric parameters, blood components, and dietary intake were measures at the beginning of study period and after 6 month. Cost-effective analysis included direct labor costs, educational materials and medication cost difference during 6 months. After 6 month, subjects from IE group showed significant reduction of body weight (p <0.05) and systolic blood pressure (p <0.05), whereas BE group did not show any significant changes. Result from biochemical indices showed glycated hemoglobin concentration was significantly reduced by 0.7% (p <0.05) only in the IE group. The ratio of energy intake to prescribed energy intake decreased significantly in both groups (p <0.05). Mean time taken for a dietitian to educate the subject was 67.9 ${\pm}$ 9.3 min/person for BE group, while 96.4 ${\pm}$ 12.2 min/person for IE group. Mean number of educational materials was 1.9 ${\pm}$ 0.7/person for BE group and 2.5 ${\pm}$ 0.7/person for IE group. Change in glycated hemoglobin level along the 6 month period of study can be achieved with an investment of \88,510/% by implementing BE and \53,691/% by implementing IE. Considering the net cost-effect of blood glucose control and HbA Ic, IE which provides MNT by dietitian had a cost efficiency advantage than that of BE. According to this study, MNT provided by dietitian had a significant improvements in medical and clinical outcomes compared to that of BE intervention. Therefore, MNT protocol should be performed by systemic intensive nutrition care by dietitian in clinical setting to achieve good therapeutic results of DM with lower cost.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.388-394
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• 2010

Metabolomics aims at the comprehensive, qualitative and quantitative analysis of wide arrays of endogenous metabolites in biological samples. It has shown particular promise in the area of toxicology and drug development, functional genomics, system biology and clinical diagnosis. In this study, analytical technique of MS instrument with high resolution mass measurement, such as time-of-flight (TOF) was validated for the purpose of investigation of amino acids, sugars and fatty acids. Rat urine and serum samples were extracted by selected each solvent (50% acetonitrile, 100% acetonitrile, acetone, methanol, water, ether) extraction method. We determined the optimized liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) system and selected appropriated columns, mobile phases, fragment energy and collision energy, which could search 17 metabolites. The spectral data collected from LC/TOFMS were tested by ANOVA. Obtained with the use of LC/TOFMS technique, our results indicated that (1) MS and MS/MS parameters were optimized and most abundant product ion of each metabolite were selected to be monitorized; (2) with design of experiment analysis, methanol yielded the optimal extraction efficiency. Therefore, the results of this study are expected to be useful in the endogenous metabolite fields according to validated SOP for endogenous amino acids, sugars and fatty acids.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.4
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• pp.203-215
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• 2006

Field observations on the spatio-temporal distribution of organic matter of the surface sediment were carried out at 15 stations in the central parts of the South Sea of Korea from April 2002 to January 2003. The range of water temperature and salinity in bottom waters, mud content and water content of surface sediment were $8.06{\sim}23.35^{\circ}C,\;29.20{\sim}34.51\;psu,\;71.2{\sim}99.9%$ and $38.7{\sim}68.9%$, respectively. Measured parameters on the surface sediments of ignition loss (IL), chemical oxygen demand (CODs), phaeopigment, particulate organic carbon (POC) and particulate organic nitrogen (PON) also ranged in $3.9{\sim}l2.5%,\;9.60{\sim}44.05\;mgO_2/g-dry,\;1.58{\sim}29.51\;{\mu}g/g-dry,\;3.12{\sim}13.01\;mgC/g-dry$ and $0.49{\sim}2.00\;mgN/g-dry$, respectively. The spatio-temporal distribution of organic matter demonstrated higher concentrations offshore than at lesions near the coastal line. Higher concentrations occurred in the summer and spring. The results indicated that the origin of organic matter in surface sediments in the central part of the South Sea was autochthonous rather than allocthonous because the organic matter had an average C/N ratio of 6.44 (${\pm}0.51$). However, the composition of autochthonous organic matter was mainly derived from detritus rather than living phytoplankton, which was Indicated by the results of the POC/phaeopigment ratio. A principal component analysis (PCA) indicated that 73.2% of the variability in the data was described by two factors: 1) an 'environmental factor concerning the accumulation of materials (57.3%)' and 2) 'origin of organic matter and the composition by primary production (15.9%)'. The sedimentary environment in the central part of the South Sea was divided into four regions from the factor score of the PCA by the concentrations of organic matter and the composition ratio of organic matters from phytoplankton in surface sediments.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.5
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• pp.689-695
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• 2011

Diabetic patients need nutritional education more than those suffering from other diseases because of the necessity of controlling blood glucose levels with dietary treatment. The purpose of this study was to find out the effectiveness of nutrition education on diabetes control and antioxidant status, both of which are related to diabetic complications. Thirty (15 males and 15 females) type 2 diabetes mellitus patients aged $66.7{\pm}8.8$ years participated in a 4-week nutrition education program. Nutrient intakes, blood glucose level, antioxidant status, and DNA damage were evaluated before, immediately after, and three months after the education program. Changes in those parameters over time were analyzed using repeated-measures analysis of covariance. Over time, HbA1c (p=0.000), plasma total cholesterol (p=0.002), plasma thiobarbituric acid related substances (TBARS; p=0.000), and leukocyte DNA damage (p=0.000) significantly decreased; plasma retinol (p=0.001), plasma tocopherol (p=0.000), erythrocyte catalase (CAT; p=0.000), and erythrocyte glutathione peroxidase (GPx; p=0.000) significantly increased. In an evaluation of nutrient intakes by Dietary Reference Intakes for Koreans (KDRI), energy (p=0.009), phosphorus (p=0.033), sodium (p=0.001), potassium (p=0.019), zinc (p=0.043), riboflavin (p=0.050), folic acid (p=0.048) and vitamin C (p=0.008) intakes had significant positive changes. In a correlation analysis of the biochemical and nutritional changes resulting from the education program, plasma TBARS were negatively correlated with potassium (r=-0.418, p<0.05), iron (r=-0.443, p<0.05), riboflavin (r=-0.432, p<0.05), and folic acid (r=-0.446, p<0.05) intakes, while plasma retinol was positively correlated with energy (r=0.543, p<0.01), protein (r=0.543, p<0.01), phosphorus (r=0.425, p<0.05), iron (r=0.485, p<0.05), zinc (r=0.570, p<0.01) and niacin (r=0.510, p<0.05) intakes. Erythrocyte CAT was positively correlated with folic acid intake (r=0.605, p<0.01). From these results, we suggest that an improvement in nutrition resulting from a diabetic education program for type 2 diabetes patients led to improvement in their antioxidant status, also possibly reducing complications resulting from diabetes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.855-864
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• 1996

The purpose of this study is to evaluate nutritional status of tube feeding patients, and to investigate the effects of giving enteral nutritional support to them. 83 in-patients have been examined for their nutritional status. The mean caloric density was 0.77kca1/m1. 36.1% to 75.9% of them were malnourished in terms of biochemical assessment. The energy intake showed the significant and positive correlation in all biochemical parameters. And the protein intake showed the significant and positive correlation in total protein, serum albumin, serum iron, hemoglobin, hematocrit and TLC. But age was correlated negatively to serum albumin and transferrin. The amount of energy and protein intake has been significantly increased as the tube feeding duration became longer. Also the effect of enteral nutritional support for 6 weeks has been investigated. Case group(n=8) was administered 250kca1 of polymeric formula in addition to their usual diet, while control group(n=8) kept the amount of their original intake. When comparing the biochemical changes of the case group and those of control group at week 0 and week 6 respectively, it showed significant differences in total protein, serum transferrin and TLC. This study suggests that the malnourished status of tube feeding patients can be improved and even prevented if nutritional support is properly administered.

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.275-282
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• 2010

A characteristic study of aqueous chlorine dioxide generation from sodium chlorite($NaClO_2$) by an undivided electrochemical cell with different anode materials were performed. $IrO_2$-coated Ti, $RuO_2$-coated Ti and DSA were used as anode materials and Pt-coated Ti electrode was used as cathode. Various electrochemical cell operating parameters such as cell residence time($t_R$), initial feed solution pH, sodium chlorite and sodium chloride(NaCl) concentration and applied current for the generation of chlorine dioxide in an un-divided cell were investigated and optimized. Estimated optimal cell residence times in $IrO_2$-coated Ti, $RuO_2$-coated Ti and DSA anode material systems were around 2.27, 1.52 and 1.52 sec, respectively. Observed optimum initial feed solution pH was around 2.3 in all anode material systems. Optimum sodium chlorite concentrations in $IrO_2$-coated Ti, $RuO_2$-coated Ti and DSA anode systems were around 0.43, 0.43 and 0.32 g/L, respectively. Optimum electrolyte concentration and applied current were around 5.85 g/L and 0.6 A in all anode systems. Current efficiencies of $IrO_2$-coated Ti, $RuO_2$-coated Ti and DSA anode systems under optimum conditions were 79.80, 114.70 and 70.99%, respectively. Obtained energy consumptions for the optimum generation of chlorine dioxide were 1.38, 1.03 and $1.61W{\cdot}hr/g-ClO_2$, respectively.