• Journal of Environmental Science International
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• v.24 no.12
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• pp.1657-1671
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• 2015

In this study, the wind direction and the wind speed of the nearest temperature observations point of the National Weather Service was analyzed in order to investigate the rapid rise and drop of water temperature in the East Coast appeared after passing of the 2015 typhoon No. 9 and 11. Then the figures were simulated and analyzed using the WRF(weather research and forecast) model to investigate in more detailed path of the typhoon as well as the changes in the wind field. The results were as follows. A sudden drop of water temperature was confirmed due to upwelling on the East coast when ninth typhoon Chanhom is transformed from tropical cyclones into extra tropical cyclone, then kept moving eastwards from Pyongyang forming a strong southerly wind after 13th and this phenomenon lasted for two days. The high SST(sea surface temperature) is confirmed due to a strong northerly wind by 11th typhoon Nangka. This strong wind directly affected the east coast for three days causing the Ekman effect which transported high offshore surface waters to the coast. The downwelling occurred causing an accumulation of high temperature surface water. As a results, the SST of 15m and 25m rose to that of 5m.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.217-219
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• 2006

This study focused an water quality response to land-based pollution loads and the appropriate pollutant load reduction in Chinhae Bay using an eco-hydrodynamic model. Land-based discharge foam urban areas, industrial complex and sewage treatment plant was the greatest contributor to cause red-tide blooms and summer hypoxia. Tidal currents velocity af the ebb tide was about 10 cm/s stronger than that of the flood tide. A residual current was simulated to. have a slightly complicated pattern with ranging from 0.1 to. 2.7 cm/s. In Masan Bay, pollutant materials cannot flaw from the inner to the outer bay easily because af residual currents flaw southward at surface and northward at the bottom. The simulation results of COD distribution showedhigh concentrations aver 3 mg/L in the inner part of Masan Bay related pollutant discharge, and charge, and lower levels less than 1.5mg/L in the central part of Chinhae Bay. For improvement water quality in Chinhae Bay, it is necessary to reduce the organic and inorganic loads from paint sources by mare than 50% and ameliorate severe polluted sediment.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.2
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• pp.76-86
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• 1999

It is necessary to estimate the groundwater recharge rate properly to predict the demand of groundwater and to establish the plan for the development of groundwater in the future. In this paper, A small basin in Chojung area is selected to calculate the groundwater recharge rate. In the calculation, water balance analysis, SCS-CN (Soil Conservation Service-Curve Number) method. groundwater-level analysis and hydrograph of outflow analysis are applied to this area. Data of precipitation measured by Chungju climatological station for about 10 years are used for water balance analysis and SCS-CN method. For the groundwater-level analysis. variations of groundwater-level measured from the 3 test wells in 1997's are used and stage-discharge rating curves in this area for 3 years are used for the hydrograph of outflow. The recharge rate calculated by water balance is 19%, 12.95% by SCS-CN method. 16.51% by groundwater-level analysis and 10.9% by hydrograph of outflow analysis and the overall average recharge rate is about 14.84%.

• Korean Journal of Ecology and Environment
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• v.43 no.1
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• pp.142-149
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• 2010

Tadpole shrimps are aquatic crustaceans adapted to temporary water pool. Since they have been recorded as the living fossil, there are a number of reports on their past and present distribution as well as their morphology and reproduction in foreign countries. However, there are few studies of biology and ecology of tadpole shrimps despite registration as an endangered species by Ministry of Environment, in Korea. This study was carried out to examine the distribution and habitat characteristics of tadpole shrimps (Triops longicaudatus) collected from May 2006 to July 2008 in Korea. Tadpole shrimps were found from the paddy fields and ephemeral pools at 21 countries in South Korea. They appeared between May and July and survived for 30 days, and temperatrue range was $10.7^{\circ}C$ to $33.5^{\circ}C$. The average turbidity of experimental paddy fields was 176.8 (${\pm}239.3$) NTU, and controlled field was 28.9 (${\pm}26.7$) NTU. The life pattern of tadpole shrimps is adapted to a temporary water pool and unstable environmental conditions, and also there was great effect of agricultural activity on the development and growth of tadpole shrimps.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.459-468
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• 2022

Long-term data analyses and bioassay experiments were conducted to assess limiting nutrients in Cheonsu Bay and Taean sea. First, long-term nutrient data (2004-2016) provided by the National Water Quality Monitoring Network were used to assess potential limiting nutrients. Analysis of the long-term data showed that the dissolved inorganic nitrogen/dissolved inorganic phosphate (DIN/DIP) ratio was mostly below 16, with N limitation being dominant. A subsequent analysis using the concentration ratios of N, P, and Si showed that N limitation was dominant during summer and autumn but that Si limitation occasionally occurred during winter and spring in relatively limited areas. However, the dominant limiting nutrient was not determined. The nutrient analysis of the field water collected during the bioassay experiment showed that DIN/DIP revealed P limitation at all stations in March and May, whereas N limitation was dominant in July and October. In the analysis using the concentration ratios of N, P, and Si, P and Si limitation appeared in March and May, but there were points with no dominant limiting nutrient. However, N limitation was dominant in July and October. In the bioassay experiment for assessment of the actual limiting nutrient, the results showed no specific limiting nutrient in March, whereas NH₄⁺ and NO₃^- showed responses in May, July, and October, which confirmed that N was a substantial limiting nutrient directly involved in phytoplankton growth during this period.

• Journal of Bio-Environment Control
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• v.20 no.3
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• pp.204-210
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• 2011

This experiment was conducted to investigate the effect of water states (water, osmotic potential and turgor pressure) of fruit vesicle and leaf on soluble solids and organic acid contents of fruits of 'Shiranuhi' mandarin hybrid, M16 A line during the fruit maturing season in plastic house cultivation. The 'Shirauhi' grafted on 'Swingle citrumelo', strong strength of rootstock, produced fruit with lower soluble solids and organic acid content than 'Trifoliate' orange rootstock. The fruits vesicle water potential and turgor pressure measured before dawn in 'Swingle citrumelo' were higher tendency than the 'Trifoliate' orange, but osmotic potential values were lower than the 'Trifoliate' orange. The changes of leaf water potential were very similar to the fruit. The results suggest that in the 'Shirauhi' fruits grafted on two rootstocks changes of soluble solids and organic acid content of the fruit were influenced by the leaf water potential and the osmotic potential of the fruit vesicles, which might be caused by the difference of root distribution between two rootstocks.

• Journal of Periodontal and Implant Science
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• v.52 no.5
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• pp.411-421
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• 2022

Purpose: In this study, we aimed to evaluate the degree of heat generation when a novel drill design with an irrigation slot was used with metal sleeve-free (MF) and metal sleeve-incorporated (MI) surgical guides in an environment similar to that of the actual oral cavity. Methods: A typodont with a missing mandibular right first molar and 21 bovine rib blocks were used. Three-dimensional-printed MF and MI surgical guides, designed for the placement of internal tapered implant fixtures, were used with slot and non-slot drills. The following groups were compared: group 1, MI surgical guide with slot drill; group 2, MI surgical guide with a non-slot drill; and group 3, MF surgical guide with a slot drill. A constant-temperature water bath at 36℃ was used. The drilling was performed in 6 stages, and the initial, highest, and lowest temperatures of the cortical bone were measured at each stage using a non-contact infrared thermometer. Results: There were no temperature increases above the initial temperature in any drilling procedure. The only significant difference between the non-slot and slot groups was observed with the use of the first drill in the MI group, with a higher temperature in the non-slot group (P=0.012). When the heat generation during the first and the second drilling was compared in the non-slot group, the heat generation during the first drilling was significantly higher (P<0.001), and there was no significant difference in heat generation between the drills in the slot group. Conclusions: Within the limitations of this study, implant-site preparation with the surgical guide showed no critical increase in the temperature of the cortical bone, regardless of whether there was a slot in the drill. In particular, the slotted drill had a cooling effect during the initial drilling.

• KIEAE Journal
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• v.12 no.5
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• pp.29-34
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• 2012

A rental housing has a key role to supply the living space to non-ownership. A public rental housing is particularly aimed at providing the living space for the low-income households with a low rent fee. Therefore, the local government would try to maintain the facilities of the rental housing and to get the decent living condition. For getting the required living condition, it should make a maintenance plan, which contains the repair time, repair scope and targeted component and finishings. This study is aimed at providing the optimal repair time in 12 components and components of the rental housing which is controlled by the local government. The optimal repair time has two steps to get the final result. First, it would draw the 1'st repair time with the probabilistic and empirical approach. Second, comparing the drawn data and the service life, the optima repair time would be provided with considering the components' attributes. Result are as follows : First, the optimal repair time would be considered with the component attributes. There are user's convenience, its safety and physical aspect. Second, the kitchen utensils, elevator and water tap has a optimal time of 16, 19, 17 years respectively which is considered with physical aspect. In addition, the optima repair time of the wiring appliance and lighting equipment are 12 years and 10 years respectively.

• Hwankyungkyoyuk
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• v.18 no.2 s.27
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• pp.1-13
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• 2005

The purpose of this study was to investigate the environmental awareness and attitude of elementary school teachers. For this study, 100 elementary school teachers from H graduate school of education were sampled. The results of this study were summarized as follows. First, the biggest concern of environmental problems were water-pollution and garbage problems by the lack of understanding about the environment and injudicious development. Second, most teachers recognized the need for environmental education and they answered that they were doing best to teach students with the main purpose of helping them develop values of environmental preservation. Third, most environmental education was carried out during class using current events and the emphasis on garbage separation and recycling. They also showed the lack of teaching materials and field trips for environmental education. Fourth, it appeared to come from media-oriented environmental education. Most teachers mainly used newspapers and visual materials. 1'hey were obtaining knowledge and information related to environmental education through the media. Since in-service teachers' conceptions could directly effect present education, it is necessary to establish a more systematic educational system for environmental education, for in-service elementary school teachers.

• Korean Journal of Veterinary Service
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• v.24 no.2
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• pp.147-159
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• 2001

This Study was conducted to determine vaccination programs for the control of Newcastle Disease(ND) in chickens and investigate protective effect against Newcastle disease virus (NDV) after live ND vaccination. Maternal HI antibody titer level of chickens according to day(age) 1, 7, 14, 21, 28 and 35 were decreased gradually as 7.10$\pm$0.74, 6.57$\pm$0.74, 3.71$\pm$1.25, 2.20$\pm$1.03, 1.20$\pm$1.23 and 0.50$\pm$0.71. As a result of HI test and ELISA, both chickens vaccinated with VG/GA strain live vaccine at 1-day-old and chickens not vaccinated do not have antibody titer for protection against NDV at 14-day-old. Except for LaSota strain vaccine, in case of vaccination with VG/GA spray and VG/GA, B1 and LaSota strain drinking water at 14-day-old, the protective effect was 100% in chickens inoculated NDV($10^{7.2}$ $EID_{50}$/50${\mu}\ell$, eye drop) at 21-day-old, but not 10～50% at 28-day-old. These data suggest that live NDV vaccination should be given at 10-day-old 20-25day-old for protect against NDV at periodic outbreaks of ND caused by velogenic viscerotropic NDV in the environment of a farm.