• The Korean Journal of Physiology
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• v.7 no.2
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• pp.39-47
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• 1973

The influences of the acute hemorrhage on the intestinal functions were studied in the rabbits subjected to acute bleeding, amounting 1.5-2% of the body weight. The motility and the absorptive capacity of the ileum were compared before and after the bleeding. Transfusion of shed blood was also performed in order to see whether the deteriorations were reversible or not. The tension developed in the direction of the longitudinal axis of the ileum was recorded through an appropriate transducer, and the frequency of the rhythmic contraction was counted throughout the procedure. Test solution, 10ml in amount, was placed in the loop of the ileum, and the samples were drawn at zero time and at 20 minutes. Triplicated procedures were repeated on the same loop;namely, before and after bleeding and after transfusion. The test solution was composed of 200 mg% urea, 218 mEq/l of NaCl and 150 mg% of polyethylene glycol (PEG) No. 4,000 in distilled water. The latter substance was used as a marker substance for the volume change of the loop. The results obtained were as follows; 1. The motility of the ileum suffered little effects by acute hemorrhage. However, minor fluctuations were seen in the frequency of the rhythm, showing a slight tendency of decreasing rhythmicity, and it was reversed by transfusion. 2. Diminution of absorptive capacity of urea was noticed in acute hemorrhage and it was interpreted as the consequence of the secondary effect of the retardation of the active transport mechanism governing the sodium transport 3. Absorption rate of the sodium ion was dropped in the hemorrhage, suggesting the indispensable need of the blood supply. 4. Osmolarity of the luminal fluid remained higher in the case of acute hemorrhage. 5. There was a tendency of retaining more fluid in the intestinal lumen in acute hemorrhage, comparing with that observed prior to the bleeding. 6. The deteriorations in the absorptive capacity were restored by transfusion of shed blood.

• Water for future
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• v.29 no.3
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• pp.197-205
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• 1996

Flow carrying capacity of water distribution systems is getting reduced by deterioration of pipes in the systems. The objective of this study is to develop a managerial decision-making model for the rehabilitation of water distribution systems with a minimum cost. The decisions made by the model also satisfy the requirements for the discharge and pressure at demanding nodes in the system. The replacement cost, pipe break repair cost, and pumping cost are considered in the economic evaluation of the decision along with the break ratio and interest ratio to determine the optimal replacement time for each pipe. Then, the hydraulic integrity of the water distribution system is checked for the decision by a pipe network simulator, KYPIPE, if the discharge and pressure requirements, the decision made for the optimal replacement time is revised until the requirements are satisfied. The model is applied to an existing water distribution system, the Metropolita Water Supply Project (1st Phase). The result shows that the decisions for the replacement time determined by the economix analysis are accepted as optimal and the hydraulic integrity of the system is in good condition.

• Journal of the Korean Solar Energy Society
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• v.36 no.6
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• pp.25-35
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• 2016

In this study, the evaluation of the dynamic behavior and thermal performance of the "Façade integrated Natural circulation Solar Water Heating System" installed in the residential house was carried out. Experimental tests were performed during the all year around in the rural houses of $166m^2$ in size. Facade integrated solar collector of $5m^2$ were installed on the south-facing. Electrical heater of 1 kW capacity as an auxiliary heater was installed at the upper part of the heat storage tank. The analyzing results are as follows. (1) Monthly average solar fraction was 51 to 87% and yearly average value is 64%. (2) Hot water supply temperature in December which has the lowest solar altitude is 37 to $76^{\circ}C$. The highest working fluid temperature of solar collector in this period was below $84^{\circ}C$. The temperature difference of working fluid between the collector inlet and outlet has been shown to be around 9 to $26^{\circ}C$. (3) Overheating which is one of the biggest problems during summer did not appear at all, but rather had hot water supply temperature is rather low as $30{\sim}47^{\circ}C$ in summer than winter, which is supplied by a small solar load. The solar collecting temperature has been shown to maintain below $55^{\circ}C$. (5) The thermal performance of Facade integrated solar collector can be increase due to the reduction of heat loss to the back of the collector wall integration of the collector is reduced. As a conclusion, Facade integrated natural circulation type Solar Water Heating System is a well-functioning without any pumps or controllers, and it was found that the disadvantages of conventional solar water heaters, hot water or hot water system can be greatly improved.

• Journal of Environmental Impact Assessment
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• v.15 no.1
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• pp.79-92
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• 2006

Environmental capacity assessment of Busan city was conducted to provide basis for planning on sustainable development and growth of the city. Using Onish model, assessment was carried out on amenities and service facilities for the citizens of Busan city. Ecological Footprint model was used to judge if the city exceeds the its environmental capacity and to estimate the extent of the excess if it exists. The analysis using Onish model revealed that the citizens of Busan city are generally well supported by the infrastructure and service facilities of the city. Water treatment and supply facilities have enough capabilities to support the city, whereas the relatively low rate of sanitary sewer supply (78%) suggests the need for further improvement in the wastewater area. The capacities of sanitary landfills are found sufficient enough to support the city for the next 10 years. The high value for the line length served per capita in the subway sector hints on certain inconvenience of commuters. All the air quality indicators meet the Korean and WHO standards except for $NO_2$. The ecological footprint model analysis produced EF indicators for Busan city of 3.04 ha/person and 2.54 ha/person for the years of 1993 and 2003, respectively. The decrease of the indicator from 1993 to 2003 is mainly due to the incorporation of Gijang area by Busan city in 1995, suggesting the importance of the ecologically productive area in the evaluation using this model. The analysis on the ecological deficit that is based on ecologically productive land shows that the consumption by Busan city exceeds its ecologically available production by 19,600% as of 2003. The area needed to support the consumption of Busan city in 2003 is 123 times as large as the present area of Busan city, which is substantially lower than the multiplier (742) obtained for Seoul city in 1997 but is higher than those observed for Chongju city (71 in 1999) and Ulsan city (39 in 2001).

• Plant Journal
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• v.10 no.4
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• pp.35-41
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• 2014

The height and capacity of the thermal storage tank can be decided by the altitude and heat load of the heat supply area. Evaporation in heat pipe can be prevented by pressurizing it with the hydraulic head of the thermal storage tank. In addition, it absorbs the expanded volume from the temperature changes and supplies water to the pipelines in case of the shortage of water. One of the most important roles of the thermal storage tank is a stable heat supply facility. It can control the heat demand by accumulating the surplus heat and supplying in changing heat demand time. The purpose of this thesis is to be helpful for the operation and maintenance of the thermal storage tanks. The study has been carried out for 18 thermal storage tanks, which have been used polyurethane foam as insulation, among 27 tanks in district heating plants. The characteristics of the insulation materials, the reasons for the damages of the insulation and how impact the insulation damages to the corrosion of the thermal storage tank have been studied.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.3
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• pp.175-194
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• 1979

The soil organic matter contents in arable land are generally low in Korea. Thus it is generally agreed that the application of organic materials to soils would be much beneficial. Present paper is a review on the effectiveness of organic mat ter application in uplands and lowlands. 1. The effect of organic matter application in uplands are of more clear and simple to explain as compared to that in lowlands. In uplands, appropriate application of organic matters such as compost and various crops residues improves the physical properties of soils leasing to increased water holding capacity, better aeration, and decrease in soil erosion. 2. In lowland, rice soils under water logged conditions the effect of organic matter application on rice yield is not straight borward and demands more refined knowledges for the interpretation of it. 3. It is found that the application of compost in rice soils is more effective when nitrogen fertilizer application is limited it dicating that nitrogen contained in the organic maerials can become available to rice plant and plays an important role for increased yield of rice under the condition where nitrogen fertilizer supply is limited. 4. Application of organic matter does not always bring about the desirable effects. Very often the organic matter application results in more intensive soil reduction leading to the accumulation of harmful substances which would can cancel out the positive effects of organic matter. This is partiunlarly true in poorly drained soils. 5. Rice straw or compost, when applied rice soils, supply sizeable amounts of available silicate to rice plant resulting in yield increase. 6. Although the effectiveness of organic matter application on rice yield in short term experiments is not consistent due to many reasons, the long term effect of organic matter is significant. 7. The term of the $O.M/SiO_2$ ratio in rice soils can serve as a criterion for the judgement of whether organic matter or silicate fertilizer is needed to be applied in a certain soil.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.222-229
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• 2006

The treatment performance and operational parameters of a tertiary wastewater treatment process a biological filtration system were investigated. The biological filtration system consisted of a nitrification filter (Fiter 1) and a polishing filter with anoxic and aerobic parts (Filter 2). SS, T-C-BOD, and T-N in effluent were kept stable at less than 3, 5 mg/L, and 5 mgN/L, respectively, under a HRT in Filter (filter-bed) of 0.37~2.3 h. T-N at the outlet of Filter 2 were about 1~5 mgN/L under the condition of LV of 50~202 m/d. In Filter 2, denitrification was accomplished under LV of 50~168 m/d in a 1 m filter-bed. However, the denitrification capacity reached the maximum when the linear velocity was increased to 202 m/d. Relationship between increase in microorganism and headloss was clearer in Filter 2. As a result, the denitrification rate increased from 1.0~2.3 kgN/($m^3-filter-bed{\cdot}d$) as the headloss increased. The COD removal rate was 6.0~9.6 kgCOD/($m^3-filter-bed{\cdot}d$) when operated with Filters 1 and 2. These results mean that captured bacteria contributed a part of COD consumption and denitrification. The maximum nitrification and denitrification rate was 0.5 and 4 kgN/($m^3-filter-bed{\cdot}d$) in Filter 1 and 2.The ratio of backwashing water to the treated water was about 5~10 %. In Filter 1, wasted sludge in backwashing was only 0.7~5.3 gSS/($m^3$-treated water). In Filter 2, added methanol was converted into sludge and its value was 8.0~24 gSS/($m^3$-treated water). These results proved that this process is both convenient to install as tertiary treatment and cost effective to build and operate.

• Korean Journal of Agricultural Science
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• v.48 no.1
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• pp.103-117
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• 2021

The severe effects of climate change, such as global warming and the El Niño phenomenon, have become more prevalent. In recent years, natural disasters such as drought, heavy rain, and typhoons have taken place, resulting in noticeable damage. Korea is affected by droughts that cause damage to rice fields and crops. Societal interest in droughts is growing, and measures are urgently needed to address their impacts. As the demand for high-quality agricultural products expands, farmers have become more interested in water management, and the demand for field irrigation is increasing. Therefore, we investigated water demand in the irrigation of drought-vulnerable crops. Specifically, we determined the water requirements for crops including cabbage, red pepper, apple, and bean in four regions by calculating the consumptive water use (evapotranspiration), effective rainfall, and irrigation capacity. The total consumptive water use (crop evapotranspiration) estimates for Dangjin-si (cabbage), Yesan-gun (apple), Cheongyang-gun (pepper) in Chungnam, and Goesan-gun (bean) in Chungbuk were 33.5, 206.4, 86.1, and 204.5 mm, respectively. The volumes of groundwater available in the four regions were determined to be the following: Dangjin-si, 4,968,000 m³; Yesan-gun, 4,300,000 m³; Cheongyang-gun, 1,114,000 m³, and Goesan-gun, 3,794,000 m³. The annual amounts available for the representative crops, compared to the amount of evapotranspiration, were 313.9% in Dangjin-si, 29.5% in Yesan-gun, 56.1% in Cheongyang-gun, and 20.1% in Goesan-gun.

• Journal of Environmental Impact Assessment
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• v.6 no.1
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• pp.151-160
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• 1997

The Yangyang Pumped Storage Power Plant is being constructed by Korea Electric Power Corporation in Namdae-Chun River, Korea. The Yangyang Pumped Storage Power Plant has 1000MW capacity with upper reservior, lower reservior, hydrauric tunnel and underground power plant facilities. But NGO(Non Governmental Groups) and residents are worried about the power plant construction because of some problems, as follows. (1) Namdae-Chun River is principal salmon returning river in Korea. (2) Namdae-Chun River is main water supply source of the Yangyang country. So, brief explanation of Environmental Impacts Assessment executed by Korea Electric Power Corporation, main environmental impacts and countermeasures will be introduced.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.46-52
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• 2007

As flue gas desulfurization (FGD) wastewater contains high concentrations of nitrate and is very low in organic carbon, the feasibility of nitrate removal by autotrophic denitrification using Thiobacillus denitrificans was studied. This autotrophic bacteria oxidizes elemental sulfur to sulfate while reducing nitrate to elemental nitrogen gas, thereby eliminating the need for addition of organic compounds such as methanol. Owing to the unusually high concentrations of dissolved salts $(Ca^{2+},\;Mg^{2+},\;Na^+,\;K^+,\;B^+,\;SO_4^{2-},\;Cl^-,\;F^-,)$ in the FGD wastewater, extensive laboratory-scale and pilot-scale tests were carried out in sulfur-limestone reactors (1) to determine the effect of salinity on autotrophic denitrification, (2) to evaluate the use of limestone for pH control and as source of inorganic carbon for microbial growth, and, (3) to find the optimum environmental and operational conditions for autotrophic denitrification of FGD wastewater. The experimental results demonstrated that (1) autotrophic denitrification is not inhibited up to 1.8 mol total dissolved salt content; (2) inorganic carbon and inorganic phosphorus must be present in sufficiently high concentrations; (3) limestone can supply effective buffering capacity and inorganic carbon; (4) the high calcium concentration may interfere with pH control, phosphorus solubility and limestone dissolution, hence requiring pretreatment of the FGD wastewater; and, 5) under optimum conditions, complete autotrophic denitrification of FGD wastewater was obtained in a sulfur-limestone packed bed reactor with a sulfur:limestone volume ratio of 2:1 for volumetric loading rates up to 400g $NO_{3^-}N/m^3.d$. The interesting interactions between autotrophic denitrification, pH, alkalinity, and the unusually high calcium and boron content of the FGD wastewater are highlighted. The engineering significance of the results is discussed.