• Title/Summary/Keyword: Water distribution ratio

Search Result 736, Processing Time 0.03 seconds

Optimization of distribution basin and ratio at valve opening in the water treatment process (정수공정에서 분배조 및 밸브 개도율 최적화)

  • Cho, Youngman;Ryu, Dongchoon;Yoo, Pyungjong
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.29 no.5
    • /
    • pp.559-564
    • /
    • 2015
  • Distribution basins are used widely in the water treatment process. Uniform distribution at the distribution basin is an important because it affect precipitation efficiency of sedimentation basin. Generally distribution basin has a free surface water and is consisted of a weir. Study result, when inflow of distribution basin is less, amount of overflow is much at the nearest weir from the inlet. But when inflow is much, amount of overflow is much at the far weir from the inlet. The difference of distribution amount at the pipe is affected by the curvature and length of the pipe. The magnitude of the effect is determined by the relative energy loss and the flow state of the distribution basin. Optimization of the response surface method for minimizing an amount of deviation of the distribution is a very useful technique to determine the optimal ratio of the valve opening.

Probability Distribution Characteristics of water Supply Demand (상수사용량(上水使用量)의 확률분포(確率分布) 특성(特性))

  • Mock, Dong-Woo;Hyun, In-Hwan
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.8 no.2
    • /
    • pp.35-42
    • /
    • 1994
  • This study is to analyse probability distribution characteristics of water supply demand. Two cities located near Seoul were selected as study areas. In this study, two probalility distribution types were tested using the K-S(Kolmogorov-Smirnov) method. The K-S method was used to prove the goodness of the selected distribution type. And also, the goodness of maximum day demand to average day demand ratio which was obtained by field data was tested. Conclusions are as follows. 1.Bothl normal distribution type and lognormal distribution type are appropriate as the probalility distribution type for the water supply demand. 2. The probability distribution characteristics can be used to test the goodness of the maximum day to average day demand ratio.

  • PDF

Distribution of Water Masses and Characteristics of Temperature Inversion in the Western Seas of Jeju Island in Spring (봄철 제주도 서부해역의 수괴 분포와 수온역전 특징)

  • Kang, So-Young;Moon, Jae-Hong
    • Ocean and Polar Research
    • /
    • v.44 no.3
    • /
    • pp.191-207
    • /
    • 2022
  • Using the results of CTD casts made in Spring from 2017 to 2021, in this study we investigated the water mass distribution and occurrence of temperature inversion in the western seas of Jeju Island in spring. The distribution of water masses was characterized by cold and fresh water in the northwest and warm and saline water in the southeast, forming a strong thermohaline front running in the southwest-to-northeast direction. Strong temperature inversion mainly occurred in the frontal boundary when the cold water intrudes beneath the warm water at depths of 30-50 m. Analysis of the mixing ratio demonstrated that Jeju Warm Water is dominantly distributed in the western seas of Jeju Island, but its ratio can be modified depending on the southward extension of Yellow Sea Cold Water (YSCW). Results of in situ measurement showed that in 2020, the YSCW largely expanded to the western seas of Jeju Island, occupying approximately 40 % of the mixing ratio. Due to the expansion of YSCW, a strong thermohaline front was formed in the study area, thereby causing thick and strong temperature inversion. On the other hand, in 2018 the mixing ratio of YSCW was minimum (~18%) during the study period of 2017-2021, and thus a relatively weak frontal boundary was formed, without the occurrence of temperature inversion. The observational results also suggest that the interannual changes of water mass distribution and the associated temperature inversion in the western seas of Jeju Island are closely related with wind-driven Yellow Sea circulation in spring, which is the summer monsoon transition period.

Sensitivity Analysis of ILLUDAS Model Parameters Based on Rainfall Conditions (강우조건이 ILLUDAS 모형 매개변수의 민감도에 미치는 영향 분석)

  • Lee, Jong Tae;Kim, Tae Hwa
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.18 no.6
    • /
    • pp.748-757
    • /
    • 2004
  • In this study, we analyzed the sensitivity of parameters which affect the result of ILLUDAS model, in the various rainfall conditions. The three basins including Namgaja, Kings creek, Gray haven were selected for this research. The rainfall conditions are considered in terms of the rainfall frequency, the duration and the distribution. In most cases, the impermeability area ratio, the sewer slope, and the sewer roughness coefficient give more significant effects on the results than others. The results show that as increasing the rainfall frequency, the sensitivity of the parameters, sewer slope and roughness coefficient are rised, while the impermeability area ratio is decreasing. And also, for the duration of rainfall, the impermeability area ratio's sensitivity shows similar tendency. In case of the rainfall distribution, the parameters of the sewer roughness and the impermeability area ratio show more sensitive in Huff distribution. Especially, The impermeability area ratio is the most sensitive parameter in Central blocking and Yen & Chow distributions respectively.

Effect of Flow Direction on Two-Phase Flow Distribution of Refrigerants at a T-Junction

  • Tae Sang-Jin;Cho Keum-Nam
    • Journal of Mechanical Science and Technology
    • /
    • v.20 no.5
    • /
    • pp.717-727
    • /
    • 2006
  • The present study experimentally investigated the effect of flow direction and other flow parameters on two-phase flow distribution of refrigerants at a T-junction, and also suggested a prediction model for refrigerant in a T-junction by modifying previous model for air-water flow. R-22, R-134a, and R-410A were used as test refrigerants. As geometric parameters, the direction of the inlet or branch tube and the tube diameter ratio of branch to inlet tube were chosen. The measured data were compared with the values predicted by the models developed for air-water or steam-water mixture in the literature. We propose a modified model for application to the reduced T-junction and vertical tube orientation. Among the geometric parameters, the branch tube direction showed the biggest sensitivity to the mass flow rate ratio for the gas phase, while the inlet quality showed the biggest sensitivity to the mass flow rate ratio among the inlet flow parameters.

Synthesis and Characterization of Yttrium-doped Core-Shell SiO2 Nanoparticles by Reverse Micelle and Sol-gel Processing

  • Kim, Jun-Seop;Chu, Min-Cheol;Cho, Seong-Jai;Bae, Dong-Sik
    • Journal of the Korean Ceramic Society
    • /
    • v.45 no.9
    • /
    • pp.512-517
    • /
    • 2008
  • In this study, yttrium-doped $SiO_2$ nanoparticles are synthesized using a reverse micelle technique combined with metal alkoxide hydrolysis and condensation. Spherical Y-doped $SiO_2$ nanoparticles with a uniform size distribution are prepared using selfassembly molecules in conjunction with the hydrolysis and condensation of organometallic precursors. The water/surfactant molar ratio influenced the Y-doped $SiO_2$ particles distribution of the core-shell composite particles and the distribution of Y doped $SiO_2$ particles was broadened as the water to surfactant ratio increased. The particle size of Y increase linearly as the $Y(NO_3)_3$ solution concentration increased. The average size of the cluster was found to depend on the micelle size, the nature of the solvent, and the concentration of the reagent. The effects of synthesis parameters, such as the molar ratio of water to surfactant and the molar ratio of water to TEOS, are discussed.

Statistical Analysis of Irrigation Reservoir Water Supply Index (관개용저수지 용수공급지수(IRWSI)의 확률통계 분석)

  • 김선주;이광야;강상진
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.40 no.4
    • /
    • pp.58-66
    • /
    • 1998
  • Irrigation Reservoir Water Supply Index(IRWSI), which can be applied to the effective supply and management of the irrigation water resources, was developed. IRWSI was formulated as resealed nonexceedance probabilities of two hydrologic components : reservoir storage ratio and precipitation. To generate nonexceedance probability of hydrologic component, it was important to define the optimal one among the various probability distribution function in the state of nature. To define an optimal probability distribution, in this study, four types of probability distribution function were tested by the K-S fitting, and for the calculation of IRWSI, reservoir storage ratio(%) and precipitation used Normal distribution & Gamma distribution, respectively. In this study, the weight coefficients of a and b for each hydrologic component, which is precipitation and reservoir storage ratio, was decided as 0.8 and 0.2, respectively. While some studies changed weight coefficients according to the size of basin area, this study used same values without considering that. From the analysis of drought characteristics, it was found that the IRWSI was sensitive to the size of irrigation area rather than the size of basin area, and the south-eastern region of Korea had been suffered from severe drought damage.

  • PDF

Prediction of the Degree of Saturation Using the Soil-Water Characteristic Curves on an Unsaturated Soil (흙-수분 특성곡선 방정식을 이용한 포화도의 예측)

  • Song, Chang-Seob
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.46 no.6
    • /
    • pp.61-69
    • /
    • 2004
  • The aim of the work described in this paper was to confirm the application of the equation of the soil-water characteristic curves on an unsaturated soil. A series of suction test for unsaturated soils was conducted on the selected 4 kinds of soil using modified pressure extractor apparatus. And it was carried out to analyse The experimental parameters which can be describe the soil-water characteristics, were determined by using the data obtained from the experiment. From the results, it was found that The matric suction varied according to the grain size distribution, amount of fine grain particles and void ratio. Also it was found that the residual degree of saturation was decreased with in crease of the void ratio, but the pore size distribution index and air entry value were increased with in crease of the void ratio. And The application of the soil-water characteristic curve equation was confirmed for the various conditions and the various state by the comparison between the measured degree of saturation and the predicted degree of saturation.

Prediction of the Volumetric Water Content Using the Soil-Water Characteristic Curve on an Unsaturated Soil (흙-수분 특성곡선 방정식을 이용한 체적함수비의 예측)

  • Song, Chang-Seob
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.7 no.6
    • /
    • pp.39-48
    • /
    • 2004
  • The purpose of this paper was to confirm the application of the equation of the soil-water characteristic curve on an unsaturated soil. To this ends, a series of suction test was conducted on the selected 4 kinds of soil which is located in Korea, using the modified pressure extractor apparatus. And it was carried out to analyze the experimental parameters which can describe the soil-water characteristics, were determined by using the data obtained from the experiment. From the results, it was found that the matric suction was varied according to the grain size distribution, amount of fine grain particle and void ratio. Also it was found that the residual volumetric water content was decreased with the void ratio, but the index related air entry value, the soil parameter related water content and the parameter with residual water content were increased with the void ratio. And the application of equation of the soil-water characteristic curve was confirmed for the various conditions and the various state by the comparison between the volumetric water content measured by the experiment and the predicted values.

A Study on Correlations between Muscle Circumference Ratio, Water Distribution and BMI Obese and Normality (비민인과 정상인의 근육둘레비율 및 수분분포와 BMI의 상관성 연구)

  • Park, Won-Hyung;Kim, Dong-Gun;Cha, Yun-Yeop;Kim, Jin-Yeon;Park, Byung-Cheol;Yoon, Yong-Kwan;Pyun, Ki-Wook;Hwang, Man-Young
    • Journal of Korean Medicine Rehabilitation
    • /
    • v.15 no.2
    • /
    • pp.45-54
    • /
    • 2005
  • Objectives : This study aims to confirm the importance of behavior habit and exercise, especially leg exercise in obese. Methods : Out of 2247 people, we divided 1125 people in normal group(BMI<25) and 122 people in obese group($BMI{\geq}25$). We measured each arm, leg, abdomen muscle circumference and right and left water difference using BLA. We Investigated whether ratio of leg muscle circumference to arm and abdomen has differences by statistics between each groups. And analyzed correlation with BMI. We also investigated right and left water distribution difference of two group's limbs and the correlation with BMI. Statistical analysis was performed by using SPSS program. Results : 1. In obese group, ratio of leg muscle circumference to arm and abdomen is significantly lower than normal group(P<0.001). 2. Ratio of leg muscle circumference to arm and abdomen were negatively correlated with BMI(r-0.461, r=0.462, P<0.001). And partial correlation coefficient controlled for age and sex is -0.528, -0.632(P<0.001). 3. In the case of women, there was right and left water distribution difference as statistical in leg. In the case of Obese, the difference is serious. Conclusions : These results suggest that exercise and activity of lower limbs is more needed in the field of obesity treatment and prevention.