• Asian-Australasian Journal of Animal Sciences
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• v.21 no.8
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• pp.1196-1200
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• 2008

An experiment was conducted to evaluate the physiological changes of laying hens subjected to feed removal during induced molting while received probiotics in the drinking water. Post-molt performance and egg quality criteria were also studied. Ninety 78-week-old Hy-line W36 laying hens were divided into two treatment groups according to equal body weight and subjected to induced molting by continuous feed removal until around 30% BW reduction. The experiment lasted 12 wks consisting of 4-wk molting and 8-wk post-molt periods. Treatment 1 received no probiotics and was considered as the control. Treatment 2 was similar to the control except that hens received probiotics in the drinking water at 400 mg/L during feed deprivation. The results indicated that hens in both groups went out of production by Day 5. However, hens received probiotics reached 5 and 50% egg production sooner than the control (30 and 52 days vs. 31 and 54 days). Starvation during molting increased heterophil to lymphocyte (H/L) ratio, hematocrit and plasma T4 and $Na^+$ levels while plasma T3 and Cl- levels were decreased. Probiotics had no significant impact on BW reduction during molt. Post-molt egg production and egg mass were higher in hens which previously received probiotics, but these responses were not significant. However, feed conversion ratio was significantly better in hens which received probiotics. Hematocrit, plasma thyroid hormone concentrations (T3 and T4) and plasma $Na^+$, $K^+$ and Cl- levels during molting were not significantly influenced by supplementation of probiotics. However, H/L ratio showed a significant (p<0.05) reduction in birds which received probiotics suggesting beneficial effects of this product for feed-deprived laying hens. No significant difference was observed in post-molt egg quality criteria.

• Korean Journal of Ecology and Environment
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• v.45 no.4
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• pp.347-355
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• 2012

In this study, non-point pollution sources in the Yeongsan river basin are analyzed; then, the priority regions (areas divided on a small scale) of management are selected for efficient water management of the Seungcheon and Jooksan reservoirs, which were constructed as one of the 4 major rivers restoration projects. The priority regions are decided by using the criteria of the excessive rate of target water quality, non-point pollution load per unit area, total TP load and down flow distance. The results of this study are as follows. The upper 10% of the priority regions for non-point pollution management includes YB15, YB05, YB10, YB24, YB14 and YB11 for the Seungcheon reservoir watershed, and YC24, YC25, YC30, YC34, YC22 and YC17 for the Jooksan reservoir watershed. However, a few regions in each of the Seungcheon and Jooksan reservoirs need to be selected in higher order, and the non-point pollution removal facilities in the regions need to be installed with respect to budget, urgent matter, and so on.

• Journal of Environmental Impact Assessment
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• v.20 no.3
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• pp.397-409
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• 2011

This study was carried out for improving the effectiveness of water resources development project through local resident opinions in the environmental impact assessment(EIA). The EIA reports of seven dams were examined. Four dams -Youngju Dam, Seongduck Dam, Buhang Dam and Hantangang Dam- which included many local opinions including 470 opinions of 341 local residents were selected to be analyzed. Local residents submitted their opinions in the six fields which are meteorological phenomena, water quality, land use, fauna and flora, noise and vibration, and residence, and the major opinions of those opinions came from the atmosphere environment field which is 32% of total opinions and social and economic field which is 38% of total opinions, respectively. In submerged area, opinions of the measure for migration and compensation were 91% and in non-submerged area, opinions of the measure for meteorological phenomena was 86%. Those percentages were maximum in each area. Opinions concerned meteorological phenomena were 86% and 53% in Youngju Dam and Seongduck Dam where area is surrounded by existing dam, but there was only 9% and 0% of opinions in Buhang Dam and Hantangang Dam where area is without existing dam nearby. The reformation methods which reflected the resident's opinions were suggested on EIA in dam development projects. First of all, reliability and objectivity of the field of meteorological phenoma should be enhanced by scientific prediction of the phenomenon days. Secondly, techniques reducing uncertainty of various water quality prediction models ought to be developed and effectiveness of the reduction strategies in environmental impact should be quantified. Finally, the draft of EIA report should involve the detailed plans of migration and compensation's procedures, criteria and measures to support.

• Korean Journal of Environmental Agriculture
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• v.10 no.1
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• pp.67-75
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• 1991

The QUAL-II E Model was applied to predict the water quality of the Mankyong drainage System, and lead to following conclusion. 1. The difference between computed and measured BOD at the M-3 (Bakgugeong) station was within 10%, indicating that the application of the QUAL-IIE Model for the prediction of water quality was satisfactory thus far. 2. The application of the model states that the discharge of concentrated pollutants at the M-1 station on the Jeonju stream, located 41Km upstream from the estuary, causes the worst problems. The sluice which extends residence time and enlarges watery surface improves water quality by a Self-purification process at the M-3 station, 28km upstream from the estuary. 3. The accuracy of the model diminished when this model was applied on the estuary downstream of the sluice. Hence, the application of the model on the estuary needs to be used with caution. 4. Among the conputed water quality parameters, BOD is the worst problem. At the M-3 station, BOD is computed to be 26.6 mg/1 in 1996, 30.7 mg/1 in 2,001, 33.0 mg/l in 2006, and 37.5 mg/1 in 2011. When preventive measures against water pollution are not properly exercised, severe problems in irrigation and water resources are expected. This study will be of used in the selection of irrigation water intake points, the criteria of effluent treatment, the management of water resources, and the establishment of water quality managemont policy.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.3
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• pp.139-146
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• 1978

The annual variations of some heavy metal concentrations, Al, Mn, Fe, Cu, Pb, Zn, Cd, Hg were determined on tile day of spring tides in every month from May 1977 to April 1978 at eight stations in the Nagdong River downstream. Samples were taken at intervals of one or two hours from 7 a.m. to 7 p.m. at each station. Annual ranges and means of concentrations of the heavy metals are as follows : aluminium 40.7-3700 ppb, 286 ppb; manganese 10.3-261.5 ppb, 80.8 ppb; iron ND-1237 ppb, 147.7 ppb; copper ND-30.9 ppb, 2.49 ppb; lead ND-29.9 ppb, 1.10 ppb; zinc ND-156.8 ppb, 5.61 ppb; cadmium ND-1.22 ppb, 0.09 ppb; mercury ND-0.37 ppb, 0.02 ppb respectively. In general, the contents of heavy metals except managanese and mercury were higher at the stations above station one, Kupo, though the ranges of the contents showed remarkable difference according to the sampling stations. Annual means of the concentrations of iron and manganese were exceeded already the desirable standards for industrial water and closed to the criteria of raw water for public supply. The values that over the criteria of raw water were sometimes found. Mercury concentration showed comparative high level such as ND-0.37 ppb in annual range but it was not over the environment criterion, 0.5 ppb. Aluminium, iron and mercury showed generally high values in summer period and other metals in winter period, through the patterns of seasonal variations were difference depending on the sampling stations and the kind of metals.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.4
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• pp.113-120
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• 2015

The objectives of this study were to monitor and assess the effects of saline irrigation water on lettuce and carrot growth in protected cultivation. One control and 4 treatments with three replications, which were differentiated according to the level of salinity in irrigated water, were employed for each vegetable to assess the effects of the irrigation with saline water. Monitoring results showed that the use of irrigation water containing above a certain level of salinity was found to cause excessive accumulation of salts in the soil as saline irrigation water increased electrical conductivity (EC) and sodium ($Na^+$) content in both lettuce and carrot soil samples, while tap water irrigation used as control decreased the salinity in the samples. The salinity higher than the threshold level of irrigation water was found to reduce the yields of lettuce and carrot, while in less than the threshold level the higher the salinity of the irrigation water increased the yields. The salinity of the irrigation water also appeared to increase the internal salinity of the plant as the $Na^+$ content in plant increased as the salinity of irrigation water increase. Increased $Na^+$ content was analyzed to be able to increase the sugar content in carrot. This study could contribute to suggest water quality criteria for safe use of saline water in protected cultivation, although long-term monitoring is needed to get more representative results.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.4
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• pp.445-452
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• 2004

Intermittent deep draw artificial circulation system is one of the most widely used destratification systems to control algal bloom in reservoirs in Korea. However, there have been neither theoretical background of design criteria nor operation guide line for efficient application of the system available for such systems. A design method was developed to calculate required compressor capacity and number of circulation units considering physical interactions between stratified water layers and plumes induced by the intermittent deep draw artificial circulation system. The program was tested with data observed in Yeoncho Lake. The results indicated that the developed method can applied in the fields successfully. Further validation processes would improve design and operation methods.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.52-59
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• 2005

The goal of this project is to estimate the instream flow of the Han River Basin to ensure the adequate supply of suitable quality water for preservation and enhancement of aquatic ecosystems. A applied model is Physical Habitant Simulation System(PHABSIM) of Instream Flow Incremental Methodology(IFIM). The parameters which are needed to simulation by PHABSIM such as flow depth, velocity distribution and channel cover with cross section data are obtained by field survey. The Habitat Suitability Criteria with the application of univariate curve on Zacco platypus as a target species was able to be established by conducting the field investigation. The estimated results of ecological recommended instream flow by this study has important meanings that the future river management have to seriously take into account for the natural environment and functions of river system.

• Journal of Soil and Groundwater Environment
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• v.17 no.2
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• pp.28-36
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• 2012

This study carried out several kinds of investigations such as geology, hydrogeology, groundwater level and quality, surface-water quality, and the quantity and quality of groundwater discharge from the subway to identify the causes of groundwater contamination around the subway tunnel at Suyeong District in Busan City. Geostatistical analyses were also conducted to understand the characteristics of groundwater level and quality distributions. There are Kwanganri Beach and Suyeong River in the study area, which are basically influenced by seawater. The total quantities of groundwater utilization and groundwater discharge from the subway tunnel in Suyeong District are 2,282,000 $m^3$/year, which is 2.4 times larger than the sustainable development yield of groundwater. The lowest groundwater level around the subway tunnel is about 32 m below the mean sea-level. The large drawdown of groundwater led to the inflow of seawater and salinized river water toward the subway tunnel, and therefore the quality of groundwater didn't satisfy the criteria of potable, domestic, agricultural and industrial uses. Distribution maps of groundwater level and qualities produced by kriging were very useful for determining the causes of groundwater contamination in the study area. The distribution maps of electrical conductivity, chloride and sulfate showed the extent of seawater intrusion and the forceful infiltration of the salinized Suyeong River. This study revealed that seawater and salinized river water infiltrated into the inland groundwater and contaminated the groundwater around the subway tunnel, because the groundwater level was seriously drawdowned by groundwater discharge from the subway tunnel. The countermeasure for the minimization of groundwater discharge from the subway tunnel is necessary to prevent the groundwater obstacles such as groundwater depletion, groundwater-quality deterioration, and land subsidence.

• Fisheries and Aquatic Sciences
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• v.11 no.1
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• pp.7-14
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• 2008

The sanitary quality of a shellfish-growing area in Kamak Bay, Korea, was assessed through a bacteriological examination of seawater and oysters from January 2004 to December 2006. From seawater samples collected at 28 stations, the range of geometric mean (GM) and the estimated 90th percentile for most-probable-number (MPN) values of fecal coliforms were <1.8-2.4 MPN/100 mL and 1.8-6.0 MPN/100 mL, respectively. The observed fecal coliform GM and the estimated 90th percentile did not exceed the fecal coliform water quality standards of 14 MPN/100 mL and 43 MPN/100 mL. Therefore, the bacteriological quality of seawater at this shellfish-growing area met the Korean Shellfish Sanitation Program (KSSP) criteria for a growing area used for export. The range of the fecal coliform GM and the estimated 90th percentile MPN values of oyster samples were 19.2-160 MPN/100 g and 20.2-166.9 MPN/100 g, respectively, and the range of the viable cell count was 30-1900 CFU/g. Thus, the fecal coliform value for the oysters and the viable cell count were less than the current shellfish quality standards of 230 MPN/100 g and 50,000 CFU/g, respectively. The bacteriological quality of the oysters complied with the criteria for domestic use and export of shellfish.