• Journal of Korean Society on Water Environment
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• v.26 no.5
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• pp.754-760
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• 2010

This study was carried out not only to evaluate optimal operating condition to increase biogas production, but also to estimate feasibility of renewable energy from anaerobic digester of sewage sludge. Semi- continuous Fed and Mixed Reactors (SCFMRs) were operated in various condition to quantify the reactor variables. The result of SCFMR operation showed that the biogas productivity and total volatile solids (TVS) removal of total solids (TS) 4% reactor at hydraulic retention time (HRT) 20 days with Organic Loading Rate (OLR) of $1.45kg/m^3-d$ were $0.39m^3/m^3-d$ and 26.7%, respectively which was two times higher than that of TS 2.5% reactor. Consequently the daily biogas production of $20,000m^3$ would be possible from the total volume of $52,000m^3$ of anaerobic digesters of the municipal wastewater treatment plant in D city. In feasibility study for the Biogas utilization, combined heat and power system (CHP) and CNG gasification were examined. In case of CHP, the withdrawal period of capital cost for gas-engine (GE) and micro gas-turbine (MGT) were 7.7 years and 9.1 years respectively. biogas utilization as Clean Natural Gas (CNG) shows lower capital cost and higher profit than that of CHP system. CNG gasificaion after biogas purification is likely the best alternative for Biogas utilization which have more economic potential than CHP system. The withdrawal period of capital cost appeared to be 2.3 years.

• Atmosphere
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• v.29 no.4
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• pp.501-509
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• 2019

Asian Dust is a meteorological phenomenon that sand particles are raised from the arid and semi-arid regions-Taklamakan Desert, Gobi Desert and Inner Mongolia in China-and transported by westerlies and deposited on the surface. Asian dust results in a negative effect on human health as well as environmental, social and economic aspects. For monitoring of Asian Dust, Korea Meteorological Administration operates 29 stations using a continuous ambient particulate monitor. Kim et al. (2016) developed an automatic quality check (AQC) algorithm for objective and systematic quality check of observed PM₁₀ concentration and evaluated AQC with results of a manual quality check (MQC). The results showed the AQC algorithm could detect abnormal observations efficiently but it also presented a large number of false alarms which result from valid error check. To complement the deficiency of AQC and to develop an AQC system which can be applied in real-time, AQC has been modulated. Based on the analysis of instrument status codes, valid error check process was revised and 6 status codes were further considered as normal. Also, time continuity check and spike check were modified so that posterior data was not referred at inspection time. Two-year observed PM₁₀ concentration data and corresponding MQC results were used to evaluate the modulated AQC compared to the original AQC algorithm. The results showed a false alarm ratio decreased from 0.44 to 0.09 and the accuracy and the probability of detection were conserved well in spite of the exclusion of posterior data at inspection time.

• Atmosphere
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• v.29 no.4
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• pp.429-438
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• 2019

Organic carbon (OC) and elemental carbon (EC) in PM_2.5 were measured with Sunset Laboratory Model-5 Semi-Continuous OC/EC Field Analyzer by NIOSH/TOT method at Anmyeondo Global Atmosphere Watch (GAW) Regional Station (37°32'N, 127°19'E) in July and August, 2017. The mean values of OC and EC were 3.7 ㎍ m^-3 and 0.7 ㎍ m^-3, respectively. During the study period, the concentrations of reactive gases and aerosol compositions were evidently lower than those of other seasons. It is mostly due to meteorological setting of the northeast Asia, where the influence of continental outflow is at its minimum during this season under southwesterly wind. While the diurnal variation of OC and EC were not clear, the concentrations of O₃, CO, NOx, EC, and OC were evidently enhanced under easterly wind at night from 20:00 to 8:00. However, the high concentration of EC was observed concurrently with CO and NOx under northerly wind during 20:00~24:00. It indicates the influence of thermal power plant and industrial facilities, which was recognized as a major emission source during KORUS-AQ campaign. The diurnal variations of pollutants clearly showed the influence of land-sea breeze, in which OC showed good correlation between EC and O₃ in seabreeze. It is estimated to be the recirculation of pollutants in land-sea breeze cycle. This study suggests that in general, Anmyeondo station serves well as a background monitoring station. However, the variation in meteorological condition is so dynamic that it is primary factor to determine the concentrations of secondary species as well as primary pollutants at Anmyeondo station.

• BMB Reports
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• v.45 no.6
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• pp.337-341
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• 2012

Different from humans, who have a continuous dentition of teeth, mice have only three molars and one incisor separated by a toothless region called the diastema in the hemi mandibular arch. Although tooth buds form in the embryonic diastema, they regress and do not develop into teeth. In this study, we evaluated the proteins that modulate the diastema formation through comparative analysis with molar-forming tissue by liquid chromatography-tandem mass spectroscopy (LC-MS/MS) proteome analysis. From the comparative and semi-quantitative proteome analysis, we identified 147 up- and 173 down-regulated proteins in the diastema compared to the molar forming proteins. Based on this proteome analysis, we selected and evaluated two candidate proteins, EMERIN and RAB7A, as diastema tissue specific markers. This study provides the first list of proteins that were detected in the mouse embryonic diastema region, which will be useful to understand the mechanisms of tooth development.

• Journal of Community Nutrition
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• v.3 no.2
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• pp.103-109
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• 2001

With a continuous and steep increase in life expectancies, Korean society is expected to enter the aged society by year 2020. And as the number of elderly increases, the burden of medical and health care expenses for them becomes greater in every developed society. Hence, the preventive approach for chronic degenerative diseases remains to be the best solution for the above-mentioned problem and warranting optimal nutrition would be one of the most important approaches. We performed a nutrition survey on 585 older adults of 50 years of age and older, residing in 3 metropolitan areas including Daejun, Daeku and Kwangju. Anthropometry, including body composition analysis based on the bioelectrical impedance analysis using InBody 3.0 and dietary intake survey by semi-quantitative flood frequency questionnaires, were used in collecting data. As one of the most important factors affecting the health and nutritional status of the elderly, we focused on living arrangements. Analyses were performed on the data from 550 subjects only, after excluding statistical outliers. Three hundred and sixty-eight of them(66.9%) were female and the number of elderly(65 years of age and older) was 485. According to the statistical analyses, the female elderly were more vulnerable to malnutrition than the male elderly. And the older they befame, the less adequate they were in nutrient intake. In addition to this, the elderly living alone showed the poorest patterns of nutrient intake and anthropometry. Although the exact effect of living alone could differ among different sex-age groups, the fact that the elderly living alone is vulnerable to malnutrition would remain concrete. This raises the utmost necessity of nutrition intervention to be devised and directed to the targeted population, namely the living-alone elderly from the government level. The intervention may include nutrition education, nutrition counseling and support In forms of meal service by networking the efforts of central as well as local governments to ensure the good health of the Korean elderly.

• Korean Journal of Community Nutrition
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• v.15 no.3
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• pp.393-402
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• 2010

The purpose of this study was performed to evaluate the prevalence of overweight and to compare the dietary behaviors, nutrient intake and physical activities of specialized game high school students. Total of 163 subjects participated and their weight, height, waist circumference, hip circumference and bone status by a quantitative ultrasound method were measured. The subjects were surveyed by a self-administered questionnaire about general characteristics, dietary behaviors and physical activities. Nutrient intakes of the subjects were assessed by semi-quantitative food frequency questionnaire. The subjects were divided into four groups on their obesity level by BMI. The prevalence of underweight, normal, overweight and obese group was 6%, 58%, 16%, and 20% respectively. BMI was negatively correlated with bone mineral density (p < 0.01) and positively correlated with WHR (p < 0.01). The dietary guideline compliance score for "Enjoy Korean rice food style" was 2.63, followed by "Prepare food sanitarily"2.48, "Do not skip breakfast"2.29, "Eat a variety of vegetables, fruits, dairy products daily"2.25, "Drink water instead of beverage"2.10, "Choose less fried foods"2.09 and "Maintain healthy weight"1.91. The exercise frequency of walking was not significantly different between groups; however, heavy exercise frequency was significantly lower in underweight group than the other groups (p < 0.05). The energy intake was 2153 kcal, which was 81.2% of the Estimate Energy Requirement, and the intake of calcium and vitamin $B_2$ was 66.7% and 77.8% of KDRIs. Particularly, the intake of iron, vitamin A and vitamin C was about 59.4%, 52.2% and 55.4% of KDRIs and INQ was 0.71, 0.63 and 0.65 respectively, and intake of folic acid fell behind 39.1% of KDRIs and INQ was 0.46. Our study suggests that the systematic and continuous nutrition education will have to be provided at schools to improve dietary and health behaviors and prevent chronic metabolic disease for students of specialized game high school.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.3
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• pp.42-50
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• 2003

Pyrolysis of maize is experimentally investigated in bench-scale rotary kiln in semi-continuous operation. The operational parameters varied are the temperature($450{\sim}800^{\circ}C$), the solids residence time(7~20 min). Important parameters studied include the running time, water content of sewage sludge, solids amount of sewage sludge(TS%) by the varied temperature. Also, with the increasing of temperature, how the yield of oil and char product change was observed, and the distribution of gas production components was observed. The gas of $C_1{\sim}C_3$ yield increased and oil of $C4{\sim}C6$ yield decreased along with pyrolysis temperature of $670^{\circ}C$ by the run time of 9 min. The results showed the expected strong influence of pyrolysis temperature and a noticeable influence of running time.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.5009-5018
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• 2014

Introduction: Numerous countries have launched campaigns regarding sun protection in the last decades. Aim: The aim of the present study was to assess an intervention program aimed at higher knowledge and healthier attitudes regarding sun protection. Materials and Methods: The sample consisted of 4,133 students aged 8-12 years from a single Greek province. Results: In most items, knowledge levels after the intervention were found to be higher than those before ($2.8{\pm}0.9$ vs $3.3{\pm}0.9$), while knowledge about sun protection factors seems to have had the highest improvement (27.1% vs 56.6%). However, student attitudes did not appear to improve, with the exception of applying sunscreen with a higher SPF (29.7% vs 54.8%). Girls seemed to have healthier attitudes compared to boys, but gender played no role with regard to knowledge levels. Also, place of residence did not play any role regarding knowledge levels, although those living in semi-urban areas seemed to have more unhealthy attitudes. Logistic regression by correlating knowledge and attitudes established that higher knowledge levels are usually accompanied by healthier attitudes, albeit marginally. Conclusions: The intervention had a positive contribution to the student knowledge level regarding sun protection and also led to small improvements regarding some attitudes. Continuous similar interventions could lead to better results and the adoption of healthier attitudes.

• Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.182-188
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• 1999

Production of extracellular polysaccharide by Monilinia fructigena in B-I medium containing cereals was higher than that in glucose medium. Productivities in B-I medium and glucose medium were 0.7g/l nd 0.2-03g/l respectively. The maximum content of polysaccharide occurred at the rising point from the lowest pH of culture. As the apparent viscosity of the polysaccharide solution increased, the flow Index (m) decreased, and the consistency Index (Kc) also increased. The polysaccharide solution was a typical pseudoplastic fluid. The mycelium was separated from the culture solution by $300\mu m$ mesh-filter and the polysaccharide was precipitated by adding 50% of ethanol (v/v). The amount of the polysaccharide removed from the filtrated solution was 0.45 g/l and the amount adhered to the mycelium was 0.25g/l. In experiments for investigating growth enhancement of rotifer (Brachionus plicatilis) by the polysaccharide, the dose of the polysaccharide was 1mg per 10,000 organisms of rotifer. Maximum specific growth rate of rotifer with feed consisting of sea Chlorella sp. and the polysaccharide was 1.095/day in the batch culture for 10 days. A semi-continuous culture was done for 30 days, the biomass of rotifer could be harvested twice. Maximum specific growth rate with sea Chlorella sp. and the polysaccharide was 0.734/day before the first harvest, and 1.685/day before the second harvest. Productivity was 38 $cells/ml\; \cdot\; day$ with sea Chlorella sp. and the polysaccharide.

• Journal of Korea Water Resources Association
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• v.38 no.9 s.158
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• pp.713-725
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• 2005

The objective of this study is to evaluate the applicability and simulation capability of PRMS, developed by U.S. Geological Survey, over the seven multi-purpose dam watersheds in Korea. The basic concepts of model components and their parameters are investigated for the evaluation of model applicability and the possibility of model parameter estimation is suggested based on the data availibility. For model parameter estimation, some parameters are directly estimated from measurable basin characteristics, but the others are estimated by Rosenbrock's automatic optimization scheme. The results show that the simulated flows from the model were very close to the observed ones. Although the default values for snowmelt model parameter are used, the results from snowmelt simulation is also acceptable. The model shows that the simulation capability is not sensitive to the basin size, however, according to increasing basin area, simulation characteristics are close to those for lumped model rather than semi-distributed model.