• 한국지하수토양환경학회지:지하수토양환경
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• 제18권1호
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• pp.123-128
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• 2013

Water quality and contamination of sediment is a growing concern in the Iksan stream of Korea. Heavy metal contamination and changes in the physicochemical properties of the stream were evaluated. Water and sediment samples were collected from six sites during the dry and rainy seasons; pH, DO, EC, ORP, turbidity, $PO_4$-P, $NO_3$-N and selected heavy metals (Cu, Pb, Ni, As, Zn, Cd, Hg) were measured. Results showed almost no change in pH between seasons. DO was highest at site 2 (~2.63 mg/L) in the dry season; EC (1,540 ms/m) was greatest at site 1 in both seasons. The ORP gradually increased from the dry to rainy season at most of the sites and was highest at site 5. Turbidity was highest at site 1 and gradually decreased from the dry to rainy season at all sites except site 3. $PO_4$-P ranged from a high of 1,193mg/L at site 1 to in the dry season to a low of ~1.2 mg/L at site 4. In contrast, $NO_3$-N was highest at site 3 in the rainy season (12,531 mg/L). Among the heavy metals measured, Cu and Zn concentrations were highest at all sediment sites. Cu and Zn are added to livestock feed to improve reproductive rates and can be carried to the stream with manure. Transport of sediment and heavy metals during the rainy season is the major source of stream contamination and it is important to continue monitoring and take necessary action in these areas.

• 패션비즈니스
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• 제10권3호
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• pp.78-86
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• 2006

Coffee extract dyeing on silk fabric using various mordanting agents at different mordanting condition was studied in our previous research. Coffee extract dyeing can exert beautiful colors and have several advantages over the conventional natural dyeing. Since most of natural dyes are expensive for mass production, strongly season and source dependent, and hard to store, and therefore, coffee waste was used as natural dye to create beautiful colors in this study. Coffee waste is inexpensive and easy to store, and provide a comparatively regular quality regardless of season and source. The effects of dyeing condition such as dyeing temperature, dyeing time, and liquor ratio on dyeing characteristics of silk fabrics were investigated. Coffee extract dyed silk showed brilliant colors, and the colors were different with the kind of mordant. Cu, Sn, and Al mordanted silks showed golden yellow with subtle change of hue and value, while Fe mordanted silk showed a brownish green color upon coffee extract dyeing. As the dyeing temperature increased, the dyeability generally increased in all mordanted silk fabrics except Fe mordanted silk until $45^{\circ}C$. The dyeing temperature did not affect the dyeability of Fe mordanted silk fabric. As the liquor ratio increased, the dyeability showed a gradual increase in all mordanted silk except Cu mordanted silk. Cu mordanted silk fabric showed an abrupt increase in dyeability at liquor ratio1:150. The dyeing time effect can be separated into 2 stages. During the initial half an hour, the dyeability did not change significantly, and then, increased after 45 min. dyeing time duration. A further increase in dyeing time after 45 min. did not affect the dyeing efficiency in all mordanted silk fabrics except the Cu mordanted.

• 한국대기환경학회지
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• 제26권1호
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• pp.34-47
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• 2010

Long-range transport of air pollutants was simulated using Comprehensive Acid Deposition Model (CADM) and Yonsei University-Sulfuric Acid Deposition Model (YU-SADM). For the simulation, weather patterns that represent the four seasons were derived through a clustering analysis with 5-years of meteorological data. The simulation result showed that in spring, influenced by strong low pressure from China, air pollutants of moved to the Korean Peninsula. In summer, humid air moved into the Korean Peninsula across the Yellow Sea while the north pacific high pressure extended, making the concentration of air pollutants lower than that in the other seasons. In autumn, air pollutants were transported by the northwest wind caused by the movement of high pressure over the Yellow Sea, while in winter air pollutants were influenced by northwest winds from continental highs. The amount of air pollutants in each season showed that high amount of pollutants were transported in winter due to the strong northwest wind. The in-flows were 3 to 8 times higher than those of the other seasons, and out-flows were about as twice as high. The amount of wet deposition in summer and autumn increased significantly compared to the amount in the other seasons due to the increase of rainfall. Source-receptor relationship analysis for sulfur showed that 70 to 91 precent of the total deposition came from the self-contribution by the Korean Peninsula. In winter, contribution from China was about 25 percent of the total deposition which was higher amount than any other season.

• 한국토양비료학회지
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• 제47권5호
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• pp.313-318
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• 2014

The remote monitoring system of water salinity was assessed in Wando reclaimed land lake during a farming season in 2009. Increasing of water salinity in this lake used to bring about salt damage on rice plant occasionally. At the early stage of the rice growing period, rice growth was not damaged due to enough rainfall with more than 120 mm from the mid-May to the first ten days of June. Data collection using on-site water salinity measuring sensors every 2 hours and real-time transmission in system were carried out for the experiment. We compared the transmitted values from the sensor system with water sample values collected and analyzed by a local technical office. Salt concentrations measured by sensor in real-time monitoring system were available data. The regression equation between rainfall and water salinity was presented as (water salinity after rainfall) = $0.621{\times}$(water salinity before rainfall)${\times}exp(-0.0139{\times}rainfall)$, ($r^2=0.579$, p<0.01). It is suggested that the system is useful for stable farming in the area where farmer use water in reclaimed lakes as an irrigation source.

• 한국환경농학회지
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• 제38권4호
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• pp.219-224
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• 2019

BACKGROUND: Soil bacteria play important roles in organic matter decomposition and nutrient cycling during the non-growing season. The purpose of this study was to investigate the effects of soil management and chemical properties on the utilization of carbon sources by soil bacteria in paddy fields. METHODS AND RESULTS: The Biolog EcoPlate was used for analyzing community-level carbon substrate utilization profiles of soil bacteria. Soils were collected from the following three types of areas: plain, interface and mountain areas, which were tested to investigate the topology effect. The results of canonical correspondence analysis and Kendall rank correlation analysis showed that soil C/N ratio and NH₄⁺ influenced utilization of carbon sources by bacteria. The utilization of carbohydrates and complex carbon sources were positively correlated with NH₄⁺ concentration. Cultivated paddy fields were compared with adjacent abandoned fields to investigate the impact of cultivation cessation. The level of utilization of putrescine was lower in abandoned fields than in cultivated fields. Monoculture fields were compared with double cropping fields cultivated with barley to investigate the impact of winter crop cultivation. Cropping system altered bacterial use of carbon sources, as reflected by the enhanced utilization of 2-hydroxy benzoic acid under monoculture conditions. CONCLUSION: These results show that soil use intensity and topological characteristics have a minimal impact on soil bacterial functioning in relation to carbon substrate utilization. Moreover, soil chemical properties were found to be important factors determining the physiological profile of the soil bacterial community in paddy fields.

• 한국농공학회지
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• 제26권4호
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• pp.52-65
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• 1984

In general precise estimation of hourly of daily distribution of the long-term run-off should be very important in a design of source of irrigation. However, there have not been a satisfying method for forecasting of stationar'y long-term run-off in Korea. Solving this problem, this study introduces unit-hydrograph method frequently used in short-term run-off analysis into the long-term run-off analysis, of which model basin was selected to be Sumgin-river catchment area. In the estimation of effective rainfall, conventional method neglects the Soil moisture condition of catchment area, but in this study, the initial discharge (qb) occurred just before rising phase of the hydrograph was selected as the index of a basin soil moisture condition and then introduced as 3rd variable in the analysis of the reationship between cumulative rainfall and cumulative loss of rainfall, which built a new type of separation method of effective rainfall. In next step, in order to normalize significant potential error included in hydrological data, especially in vast catchment area, Snyder's correlation method was applied. A key to solution in this study is multiple correlation method or multiple regressional analysis, which is primarily based on the method of least squres and which is solved by the form of systems of linear equations. And for verification of the change of characteristics of unit hydrograph according to the variation of a various kind of hydrological charateristics (for example, precipitation, tree cover, soil condition, etc),seasonal unit hydrograph models of dry season(autumn, winter), semi-dry season (spring), rainy season (summer) were made respectively. The results obtained in this study were summarized as follows; 1.During the test period of 1966-1971, effective rainfall was estimated for the total 114 run-off hydrograph. From this estimation results, relative error of estimation to the ovservation value was 6%, -which is mush smaller than 12% of the error of conventional method. 2.During the test period, daily distribution of long-term run-off discharge was estimated by the unit hydrograph model. From this estimation results, relative error of estimation by the application of standard unit hydrograph model was 12%. When estimating by each seasonal unit bydrograph model, the relative error was 14% during dry season 10% during semi-dry season and 7% during rainy season, which is much smaller than 37% of conventional method. Summing up the analysis results obtained above, it is convinced that qb-index method of this study for the estimation of effective rainfall be preciser than any other method developed before. Because even recently no method has been developed for the estimation of daily distribution of long-term run-off dicharge, therefore estimation value by unit hydrograph model was only compared with that due to kaziyama method which estimates monthly run-off discharge. However this method due to this study turns out to have high accuracy. If specially mentioned from the results of this study, there is no need to use each seasonal unit hydrograph model separately except the case of semi-dry season. The author hopes to analyze the latter case in future sudies.

• 한국지반신소재학회논문집
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• 제13권1호
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• pp.63-70
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• 2014

본 연구에서는 강우가 석산개발 주변에 위치한 하천의 오염도에 미치는 영향을 평가하기 위하여, 강우량과 중금속 오염도의 관계 및 강우량과 수질 오염도의 관계를 분석하였다. 석산개발 부지 인근의 하천에 대한 중금속 오염도 조사 결과, 매립부지에 사용된 전석, 잔사 및 석분이 직접적인 오염원으로 작용한 것으로 분석되었다. 또한 강우량 증가에 따른 하천 내 유수량이 중금속 오염도에 큰 영향을 미치는 것으로 확인되었다. 수질오염도는 우기철에서 건기철로 변화되는 시기에 증가하였으며, 강우량이 증가하면서 과거 석산개발 부지로부터 많은 부유물질이 배출된 후, 강우가 감소함에 따라 하천에 저류되어 오염도가 증가하는 것으로 나타났다. 따라서 S하천에서 지속적인 중금속 오염 및 수질오염이 발생하고 있는 원인으로는 과거 석산개발 완료 후, 매립층에 사용된 재료 및 석산개발 부지에서 오염원이 강우에 의해 배출되는 것으로 판단되었다.

• 패션비즈니스
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• 제9권6호
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• pp.29-38
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• 2005

Natural dyes have attracted the worldwide attention because of its environmental advantage over synthetic dyes. However, most of natural dyes are expensive for mass production, strongly season and source dependent, and hard to store. In this study, coffee waste were used as natural dye to create beautiful colors. Coffee waste is inexpensive and easy to store, and provides a comparatively regular quality regardless of seasonand source. The effects of mordant agent concentration and mordanting temperature on dyeing efficiency of silk fabrics were investigated. Coffee extract dyed silk showed brilliant colors, and the colors were different with the kind of mordants. Cu, Sn, and Al mordanted silks showed golden yellow with subtle change of hue and value, while Fe mordanted silk showed a brownish green color. The increase in mordant concentration did not always increase the dyeability, and 0.5% o.w.f. mordant concentration was enough to get a satifactory result. Mordanting temperature also had little effect on the dyeability in case of Al, Cu, and Sn mordanted fabrics. Only Fe mordanted fabrics showed a better dyeability in the increase in mordating temperature. Coffee extract dyeing is an effective way using waste as resource and can create brilliant colors with minimal amount of mordant and under mild mordanting condition.

• Journal of Preventive Medicine and Public Health
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• 제23권2호
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• pp.185-193
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• 1990

The purpose of this study is to observe the pattern of change in medical care utilization over time in early years of insurance coverage. The source of data is the benefit records file of a voluntary medical insurance society for covering the four-year period, from 1982 to 1985. The measure of medical care utilization used in this study is the age-sex standardized percentage of the enrollee who have visited a physician over total analytical population during a three-month period. For six cohorts by the year of enrollment ($1979{\sim}1984$), the relationship between the utilization and duration of insurance coverage was examined controlling for the calender year and season. In the analysis, logistic multiple regression and residual analysis were employed. It was observed that medical care utilization rapidly increased during the early stage of insurance coverage, and after then increased at a slower rate over time to become almost stable in about twenty months.

• 한국물환경학회지
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• 제28권3호
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• pp.453-459
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• 2012

In this study, Song-Cheon river Basin located at Dae-kwan-lyong Meyn in Kang-Won Province was monitored to analyze characteristics of non-point source pollution during the snowmelt period. The characteristics of NPS pollution such as runoff, change in water quality and pollutant loads by snowmelt were investigated from 23th February 2010 to 27th April 2010. The results showed that The climate change effects flow, turbidity and concentration of SS and COD with showing similar trend of fluctuation. Daily pollutant loads per unit area were SS 74.43 kg/ha/day, COD 1.25 kg/ha/day, BOD 0.21 kg/ha/day, TN 0.717 kg/ha/day, TP 0.141 kg/ha/day and the flow weight mean concentration has been SS 985.97 mg/L, COD 16.28 mg/L, BOD 2.67 mg/L, TN 9.302 mg/L, TP 1.834 mg/L, respectively. The flow and pollutant loads both of SS and of COD significantly increased during the snowmelt period. Because structurally loosen soil by freezing and thawing deteriorates water quality, research and management measures will be needed.