• Journal of Environmental Impact Assessment
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• v.18 no.2
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• pp.59-67
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• 2009

Water quality of the Lake Youngrang in the Sokcho City is eutrophic. Jangcheon is the largest inflow source to the lake. Major pollutant sources are stormwater runoff from resort areas and various land uses in the Jangcheon watershed. A storm sewer on the southern end of the lake is also an important pollution source. In this study, water quality modelling for Lake Youngrang was carried out considering the rainfall-runoff pollution loads from the watershed. The rainfall-runoff curves and the rainfall-runoff pollutant load curves were derived from the rainfall-runoff survey data during the recent 4 years. The rainfall-runoff pollution loads and flow from the Jangcheon watershed and the storm sewer were estimated using the two kinds of curves, and they were used as the flow and the boundary data of the WASP model. With the measured water quality data of the year 2005 and 2006, WASP model was calibrated. Non-point pollution control measures such as wet pond and infiltration trench were considered as the alternative for water quality management of the lake. The predicted water quality were compared with those under the present condition, and the improvement effect of the lake water quality were analyzed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.6
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• pp.599-607
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• 2004

The purpose of this study is to reevaluate the performance of Hanji as an architectural material. Hanji has good things in controlling indoor space comfortably. Particularly, ability of controlling humidity of Hanji affects indoor space comfort and human health. The major focuses of this experimental research are (1) how much of water vapor passes through Hanji, (2) how much of water vapor is absorbed into Hanji. In the first case, indoor humidity is higher than outdoor humidity. In this case, approximately 38 g of water vapor passes through Hanji 1, genarally utilized in window paper (Changhoji), per square meter in one hour. And approximately 4 g of water vapor is absorbed into Hanji 2, genarally utilized in wallpaper, per square meter. In the second case, outdoor humidity is higher than indoor humidity. In this case, Hanji passes water vapor to inner space at first, but when indoor relative humidity reach approximately 66%, although outdoor humidity is higher than indoor humidity, water vapor doesn't pass through Hanji. If Hanji is utilized in window material and wallpaper, indoor space is maintained comfortably without mechanical devices in humidity control.

• Journal of the korean Society of Automotive Engineers
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• v.14 no.2
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• pp.34-43
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• 1992

The purpose of this study is to consider the performance and exhaust characteristics in the practical engine according to the cooling water temperature change of engine and to set up the optimum cooling condition and to obtain the optimum operating condition of thermostat in the cooling system. In order to accomplish the purpose of this study, authors have used the following procedure. 1. This study is to investigate the influence of the cooling water temperature on the engine performance and the exhaust gas, authors regulated the cooling water temperature by using the special closing circuit and measured the concentration of exhaust gas by using the exhaust gas measuring system in the exhaust pipe. 2. This study carried out the experiment by regulating the opening degree of throttle valve and engine speed in the dynamometer and by changing the cooling water temperature, at the same time kept air-fuel ratio constant and made the spark ignition time MBT(Minimum spark advance for Best Torque) 3. This study measured the cooling water temperature by using the K-type thermocouple centring around the easy over-heated parts and by installing a special closing circuit. Therefore, in this study, authors intend to examine the influence of the cooling water temperature on the engine performance, exhaust gas and present the basic materials needed in the engine design including the optimum operating time control system for the cooling water temperature.

• Journal of Environmental Science International
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• v.21 no.2
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• pp.233-240
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• 2012

In this study, the alkiline water washing condition of mackerel(Scomber japonicus) dark meat was investigated to improve processing conditions of red muscle fish meat paste heating gel. Chemical alkaline water(CWM) and electrolytic alkiline water(EWM, pH 12) were used for washing the mackerel raw meat. Washed meats were minced with 2.5% salt and heated at $90^{\circ}C$/15 min to testing texture profile analysis. Moisture of CWM and EWM was increased with both washing times(p<0.05). Crude lipids and protiens were decreased with washing times. Lightness of chemical alkaline water washed mackerel heated paste gel(CWHPG) was higher than electrolytic alkaline water washed mackerel heated paste gel(EWHPG). Redness and yellowness were more decreased than control meats. Jelly strength of CWHPG and EWHPG was not increased more than 2 times wased meat and was increased with protein decrease. Texture profile analysis, max force1 of CWHPG and EWHPG was higher hardeness than the control meat except gel strains. From these results, it could be suggested that electric alkialine water washing is also effective in advance the red meat paste heating gel process of kamaboko industry.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.412-416
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• 2006

A magnetic field oscillator was designed and made. The oscillator was installed around a water pipe and radiated into water which was provided for vegetables cultivation. The oscillator was made with a helmholtz coil and installed a magnetic field sensor inside. The class E amplifier circuit with frequency variance was also used. Hydroponic and soil cultural methods were used for cultivation of lettuce and chinese cabbage with magnetic field water and without. Vitamin C ingredients in the lettuce and chinese cabbage which were grown with magnetic field water were 2.8 times and 1.2 times higher than without the magnetic water. Moreover, the growth acceleration effect of vegetables was shown in lettuce cultivated with the magnetic field water.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.148-155
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• 2010

Water quality and plankton community dynamics after the introduction of two domestic freshwater shellfishes (Unio douglasiae Griffith & Pidgeon and Cipangoplaudina chinese malleata Reeve), were monitored daily in enclosures, which constructed in the tidal zone of eutrophic agricultural reservoir (Shingu reservoir, Korea) for one week between July 31 and August 6, 2007. This biomanipulation study to improve the water quality of eutrophic lake, comprised eight enclosures (duplicate x four kinds), enclosure had no mussels (Control), stocked only with U. douglasiae at density of 60 individuals (UD), stocked only with C. chinese malleata at density of 60 individuals (CCM), and combined-stocked with 30 individuals of UD and 30 individuals of CCM (MIX), respectively. Our results clearly indicate that UD strongly decreased the concentration of chlorophyll-a and increased the water transparency, whereas CCM and MIX (included CCM) did increase algal density or decrease transparency, due perhaps to the disturbance of C. chinese malleata. Therefore, the field application of shellfish to enhance the water quality of eutrophic agricultural reservoir, should consider the grazing characteristics of biological control agents, especially active moving animals like snail.

• Food Science of Animal Resources
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• v.33 no.2
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• pp.170-180
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• 2013

This study was conducted to evaluate the antioxidant activity of oven-dried ($60^{\circ}C$) tomato powder (TP) as affected by water solubility and to evaluate the effects of TP on the physico-chemical properties, and antioxidant and antimicrobial activities of emulsified pork sausages with two levels of TP (1% and 2 %). After fresh tomatoes were homogenized and dried at $60^{\circ}C$ oven, they were extracted by stirring with water. Then, the aqueous solution was filtered, and water soluble and insoluble tomato powders were obtained with freeze drying. In experiment I, total phenolic contents in oven-dried tomato powder, water soluble and insoluble powder were more than 2 g/100 g. The radical scavenging activity and iron-chelation ability of the water-insoluble extracts were higher than those of dried TP and water-soluble extracts. In experiment II, pH values and Hunter L values of pork sausages formulated with TP were reduced. However, hunter a and b values were higher than those of the control, and those effects were increased with increased levels of TP. 2-Thiobarbituric acid reactive substance values of pork sausages containing TP were lower than that of the control during refrigerated storage, regardless of the TP level. These results indicated that TP could be used as a natural color agent and antioxidant in meat products without defects.

• Environmental Engineering Research
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• v.24 no.4
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• pp.582-590
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• 2019

Currently, the waterfront facility was constructed in New Songdo City, South Korea. It has the various water leisure areas and especially an artificial urban canal with filtered seawater by re-circulating flow system. However, due to excessive amount of nutrients from seawater combined with complicated geometry, it is highly vulnerable to deterioration of water quality. In this study, flow characteristics and pollutant transport were analyzed with comprehensive numerical models, MIKE 3 FM and ECO-lab. Based on these numerical results, notable sampling points were selected for field measurements and comparison between modeling and measured results were conducted. In addition, the integrated water quality evaluation index, Water Quality Index was applied to analyze various water quality issues. We also set up scenarios to control the two kinds of water quality factors, dissolved oxygen (DO), and total phosphorus (TP). As a result, the effect of 20% reduction of TP was less than 10% and it was almost ineffective for a year but it was reduced by up to 40% in case of scenario which DO is increased by 20%. Therefore, it was recommended to control the DO concentration, usually by applying re-aeration facility, rather than TP in artificial urban canal with seawater.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.1006-1015
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• 2010

We studied sea water pollution by opening the water gate of Bunam Lake in Seosan City. SS and COD were simulated. If we control the flow rate to 100ton/s, and the gate opening time to 3 hours, SS of 50ppm can be clear with in 19hours. Also, COD of 8ppm can flow for 1 hour without damaging total sea water(COD less than 2ppm). Thus, If we control the flow rate and flow time, the fish cultivation will be free from danger of water pollution.

• Journal of Soil and Groundwater Environment
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• v.18 no.6
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• pp.56-68
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• 2013

Community drinking water (CDW), mostly naturally flowing groundwater, plays important roles in supplying drinking water for urban and rural residents in Korea. Over 1,600 CDW facilities are distributed throughout the country, many of them situated in the outskirts of metropolitan cities. A large proportion of Korean people have become dependent on CDW for drinking due to a distrust of piped water's quality and a strong belief in the special medicinal effects of some CDWs. However, administrative and official management and the control of CDW facilities have been inadequate when compared with the strict examination and control of commercial bottled water, which is physically treated groundwater from deep bedrock aquifers. In this study, even though signs of anthropogenic contamination were not generally found, the tested chemical compositions of selected CDWs featured high enrichment of some constituents including Ca, Mg, Na, and HCO3 with natural origins such as water-rock interactions. Careless consumption of particular CDWs, which has no scientific basis, will not guarantee health improvement. Consequently, more intensive management of CDW facilities and a long-term interdisciplinary examination of the health effects of CDWs are needed to effectively protect people's health.