• Journal of Korean Society on Water Environment
• /
• v.23 no.6
• /
• pp.850-862
• /
• 2007

This study was carried out to survey the actual conditions of wastewater treatment facilities to obtain basic data for the management of wastewater from industrial complexes in Chungcheongnam-do province. Wastewater production flow per site area by watersheds was $49.2m^3/km^2/d$ for Sapgyoho, $8.1m^3/km^2/d$ for Anseongcheon, $5.7m^3/km^2/d$ for Seohae, and $2.9m^3/km^2/d$ for Geumgang. Sapgyoho showed 75% of the total production flow, which was the highest value, Geumgang showed 4% of total flow, which was the lowest value. Average total extra rate as production flow/capacity flow in the wastewater treatment facilities for industrial complex is 49%. Considering by watersheds, the extra rates of Seohae, Geumgang, Anseongcheon, and Sapgyoho, are 73%, 65%, 62%, and 33% respectively. This means that the design of capacity flow in wastewater treatment facilities was too large. Effluent concentration of wastewater treatment facilities did not exceed discharge limit mostly. The removal efficiency rate for water quality item was 90% in BOD, 70% in COD, 80% in SS, 30 to 80% in TN, and 20 to 90% in TP, so the organic removal was good, but the nutrient removal was low and interval of variation was high. The removal efficiency rate of the agricultural was industrial complexes is lower than the national and local complexes. The construction cost of the wastewater treatment facilities in Chungcheongnam-do was $1,756Won\;per\;m^3$, treatment cost was $189Won\;per\;m^3$, and they were about two times and 1.2 times higher than the nation-wide cost, respectively. The treatment cost consists of 39% for man power, 21% for chemical, 16% for power, 11% for sludge treatment, and 13% for others.

• Proceedings of the KIEE Conference
• /
• 1994.07b
• /
• pp.1652-1654
• /
• 1994

The Extra-high voltage XLPE cable is characterized by low transmission loss, large capacity, and high reliability. Conventionally, for XLPE cables of l54kV and above, aluminium sheath was used to be moisture barrier (thus preventing water tree deterioration of the insulation) and to protect cable core from physical stresses. However, as transmission capacity of the cable increases, so does the cable diameter and the corresponding aluminium sheath outer diameter and thickness. As a result, eddy-current loss in the sheath is increased, limiting the maximum current capacity of the cable itself. As an alternative to aluminium sheath, we have adopted stainless steel sheath with non-magnetic properties and a large resistivity, The new XLPE cable with stainless-steel sheath (CSZV cable) has drastically reduced eddy-current loss in the sheath.

• Journal of Korean Society of Water and Wastewater
• /
• v.28 no.3
• /
• pp.277-286
• /
• 2014

Water discolouration and increased turbidity in the local water service distribution network occurred from hydraulic incidents such as drastic changes of flow and pressure at large consumer. Hydraulic incidents impose extra shear stresses on sediment layers in the network, leading to particle resuspension. Therefore, real time measuring instruments were installed for monitoring the variation of water flow, pressure, turbidity and particulates on a hydrant in front of the inlet point of large apartment complex. In this study, it is attempted to establish a more stable water supply plan and to reduce complaints from customers about water quality in a district metering area. To reduce red or black water, the water flow monitoring and control systems are desperately needed in the point of the larger consumers.

• Proceedings of the KIEE Conference
• /
• 2000.07a
• /
• pp.162-164
• /
• 2000

소수력 발전은 국토의 효율적 이용과 함께 녹색의 재생에너지로 정부차원에서 건설자금과 기술을 지원하고 있다. 1984년부터 한국에너지기술연구소에서 소수력입지 조사분석, 한국형 소수력발전시스템 개발연구가 활발하게 수행되었다. 소수력발전소의 중요한 과제는 경제성 있는 지점의 선정과 운영기술의 확립으로 나타났다. 본 연구에서는 저수지에서 취수하는 광역상수도에서 소수력발전소에 대한 설계와 운영방안을 제시하고자 한다.

• Nuclear Engineering and Technology
• /
• v.56 no.1
• /
• pp.275-282
• /
• 2024

Lead bismuth eutectic (LBE) is used as coolant for MicroURANUS, a small marine nuclear power plant, and this coolant is transported in the plant by an electromagnetic pump. Given the considerable heat generated by the electromagnetic pump, the cooling of the pump is essential. This study compared air cooling and water-cooling methods and found that the maximum temperatures during air and water cooling were 640 K and 372 K, respectively. These findings were utilized to design an electromagnetic pump with water-cooling. The maximum temperature of the pump was lower than the boiling point of water; thus, the pump did not require a separate pressurization. Consequently, the resistance problem of the coil and the deformation problem of the material caused by generated heat can be solved through water-cooling.

• Korean Journal of Poultry Science
• /
• v.17 no.4
• /
• pp.310-317
• /
• 1990

An experiment was conducted to investigate the effects of adding extra dietary salt on the blood acid－base balance, water intake and egg quality in heat stressed layers. Eighteen 44－wk－old brown commercial layers(Dekalb Warren) were randomly alloted to 0.25 and 0.75% dietary salt treatments, with nine replicates per treatment and one bird per replicate. After 3 d of preliminary period at 13~$16^{\circ}C$(normal temperature), layers were subjected to 3 d of collection period. Then the room temperature was raised to 33－$35^{\circ}C$f(hot temperature), and another 3 d of collodion period was followed. The experiment was designed as a $2\times2$ factorial and analyzed as suck The ANOVA test and comparison among treatment means were done at 5% probability levels. Results obtained were summarized as follows. L The heat stressed layers decreased feed intake, and increased water intake and excreta moisture content significantly. The addition of extradietary salt significantly increased excreta moisture content 2. The heat stressed layers showed significantly higher blood pH and lower $pCO_2$ values than the control bird However, the addition of extra salt did not change any acid－base variables. 3. The egg weight and shell quality decreased significantly, and haugh unit increased significantly by the heat stress. However, these values were not affected by the salt addition. In summary, the heat stressed layers displayed respiratory alkalosis and poor egg quality, as expected However, the addition of ex03 salt to the diet failed to alleviated the heat stress in this layer experiment.

• Geomechanics and Engineering
• /
• v.29 no.6
• /
• pp.627-643
• /
• 2022

Water-rock interactions have a significant influence on the mechanical behavior of rocks. In this study, uniaxial compression and tension tests on different water-treated sandstone samples were conducted. Acoustic emission (AE) monitoring and micro-pore structure detection were carried out. Water-rock interactions and their effects on rock mechanical behavior were discussed. The results indicate that water content significantly weakens rock mechanical strength. The sensitivity of the mechanical parameters to water treatment, from high to low, are Poisson ratio (𝜇), uniaxial tensile strength (UTS), uniaxial compressive strength (UCS), elastic modulus (E), and peak strain (𝜀). After water treatment, AE activities and the shear crack percentage are reduced, the angles between macro fractures and loading direction are minimized, the dynamic phenomenon during loading is weakened, and the failure mode changes from a mixed tensile-shear type to a tensile one. Due to the softening, lubrication, and water wedge effects in water-rock interactions, water content increases pore size, promotes crack development, and weakens micro-pore structures. Further damage of rocks in fractured and caved zones due to the water-rock interactions leads to an extra load on the adjoining coal and rock masses, which will increase the risk of dynamic disasters.

• Journal of Integrative Natural Science
• /
• v.14 no.1
• /
• pp.6-10
• /
• 2021

New materials are very useful due to their wide range of applications, however, they also have caused new pollutants that damage our environment. Chemists have been conscious of the severity of these environmental problems and a great deal of effort has been put into developing environmentally benign chemical processes to synthesize new materials (green synthesis). We also have reported a green synthesis method of synthesizing silver nanoparticles using water-glycerol solution in a previous study. While conducting further research, we have recently discovered that the size of silver nanoparticles is proportional to the quantity of water present in glycerol. This method is completely benign and ecofriendly pathway, as the size of silver nanoparticles is adjusted solely by controlling the quantity of water added to glycerol, without extra additives and energy.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.6A
• /
• pp.419-426
• /
• 2012

Fresh concrete has 10~20% extra water in it. As those water remain entrapped air in the concrete, life span of structures is reduced. For that reason, if extra water is eliminated, it will be useful to improve the durability of the structures. Though there were many reports about permeable formwork, the study on the properties of permeable liner itself has been insufficient. In addition, making holes on the form causes lowering of workability. Therefore, this study reviewed the properties of woven and non-woven permeable liner and formwork which has no holes on the form. For the woven and non-woven permeable liner, they showed great application with W/C decrease, lowering roughness, increased compressive strength of surface area and slight loss of cement paste, when the were applied to concrete. In addition, they showed different performance according to the density of woven liner or thickness of non-woven liner. Furthermore, when using the draining non-woven permeable liner which has drainage path inside, concrete surface showed required performance with high workability, without drilling the holes on the form.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.28 no.2
• /
• pp.91-108
• /
• 2015

Objectives : The aim of this study was to investigate the effect of Omibaekchul-san on postpartum edema in women hospitalized at korean medical postpartum care center in comparison with Saenghwa-tang. Methods : The body composition data was collected from 102 women, who took postpartum care in postpartum care center attached to Won-kwang University Jeonju Korean Medical Hospital, from March 2012 to July 2013. The data was analyzed by Body Composition Analyzer (Inbody 720). Specifically the data was composed of the Extra Cellular Fluid/Total Body Fluid (ECF/TBF), Total Body Water (TBW), Intra Cellular Water (ICW), Extra Cellular Water (ECW), Body Weight, Body Mass Index (BMI), Waist Hip Ratio (WHR), and the ECF/TBF of each body parts such as the upperlimb, lowerlimb and trunk. The body composition was measured twice during 2~8.5 days from childbirth and once again after 7~13.5 days from childbirth by Body Composition Analyzer. Results : The Omibaekchul-san -treated group showed a significant decrease of ECF/TBF, ECW, TBF, Body weight, BMI, ECF/TBF of each body parts and increase of WHR in comparison with the data of the Saenghwa-tang-treated group. In two groups, only the change of ICW was unsignificant. Conclusions : Statistically this study suggests that the Omibaekchul-san will help the quality of life of women who are in postpartum edema.