• Title/Summary/Keyword: interception factor

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Estimation of Interception in Cheonmi Watershed, Jeju Island (제주 천미천 유역의 차단량 추정)

  • Chung, Il-Moon;Lee, Jeongwoo;Kim, Nam Won
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.4
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    • pp.815-820
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    • 2015
  • For the establishment of effective water resources management platform for Jeju-Island, the characteristics, including surface runoff, evapotranspiration, groundwater recharge and discharge are to be properly quantified. Among these hydrologic components, interception due to vegetation is very important factor but it is hard to be quantified. After Von Hoyningen-Huene (1981) found the relationship between LAI (Leaf Area Index) and interception storage, LAI has been used for key factor to estimate interception and transpiration. In this study the equation suggested by Kozak et al. (2007) is implemented in SWAT-K (Soil and Water Assessment Tool - Korea) model and is tested at the Cheonmicheon watershed in Jeju-Island. The evaporation due to interception was estimated as 85~104mm, 8~11% of whole evaporation. Therefore it is necessary to consider the evaporation due to interception as a controlling factor to water budget of this watershed.

An Estimation of Clogging Factors at Stormwater Grate Inlets with Consideration of Urban Area Characteristics (도시 지역특성을 고려한 빗물받이 유입구의 막힘계수 산정)

  • Kim, Jung-Soo;Song, Ju-Il;Yoon, Sei-Eui
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.595-598
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    • 2007
  • Urban storm water collection and conveyance systems are critical components of the urban infrastructures. During a storm event, street grate inlets are usually loaded with debris by the first-flush runoff volume. Grate inlets are subject to clogging effects. Effective interception area of grate inlets was decreased by clogging. It also decreased the interception capacity of grate inlets and increased the inundation area in street. Therefore, it is necessary to analyze the clogging characteristics and interception capacity change by clogging for appropriate design and management of grate inlets. In this study, field survey was executed to investigate debris and clogging pattern of grate inlet in 9 areas. The clogging factor with consideration of urban area characteristics was estimated with the field survey results.

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An Experimental Study for Clogging Factors Estimation of Grate Inlets in Urban Area (도시지역에서 빗물받이의 막힘계수 산정에 관한 실험적 연구)

  • Kim, Jung Soo;Kwon, In Sup;Yoon, Sei Eui;Lee, Jong Tae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.2B
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    • pp.179-186
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    • 2006
  • Effective interception area of street grate inlets was decreased by clogging with trash, debris, and sand. It also decreased the interception capability of grate inlets and increased the inundation area in street. Therefore, it is necessary to analyze the clogging characteristics and interception capability change by clogging for appropriate design and management of grate inlets. Hydraulic experimental apparatus which can be changed the gutter transverse slopes, longitudinal slopes of street and clogging condition of grate inlet ($40{\times}50cm$) was installed for this study. 81 total experiments were conducted with 8 different clogging condition. The interception capacities of grate inlets clogged curb direction are smaller than those of clogged flow direction. As the longitudinal slopes of street increase, the interception capacity of grate inlet decreases due to splash-over phenomena. This is also observed at grate inlets which has no clogging condition. In general, 50% of clogging factor was selected in design of grate inlet in foreign country. The clogging factor for same clogging condition are suggested 0.25~0.65 in domestic urban area.

The Dyeing Properties and The Functionality of Fabrics Dyed with Chelidonium Majus Extract (백굴채 추출물을 이용한 염색직물의 염색성 및 기능성)

  • Park, Young-Hee
    • Fashion & Textile Research Journal
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    • v.10 no.2
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    • pp.242-248
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    • 2008
  • This study was aimed to find whether the Chelidonium majus which grows naturally in Korean soil and has a various medical ingredient is valuable as a natural dyeing material and to examine the functionality of Chelidonium majus extract. As the test result of dyeing colorfastness, colorfastness to sunlight was 1st grade for all the dyed fabrics. The colorfastness to laundry for discoloration showed from 1st to 4th grade and that for discoloration showed from 4th to 5th grade through all the dyed fabrics. Colorfastness to perspiration, rubbing, and drycleaning showed from 4th to 5th grade through all the dyed fabrics. In the result of antibiosis test, the dyed cotton fabric showed the bacteria reduction rate of 99.0% for Staphylococcus aureus and Escherichia coli evenly when washed one, three, and five times, The dyed silk fabric, when washed one, three, and five times, showed the bacteria reduction rate of 99.0% for Staphylococcus aureus, but didn't showed the significant bacteria reduction. As the test result of sun protection test, in the case of the cotton fabric which was dyed but don't use mordant, after one-time washing, S.P.F.(Sun Protection Factor) showed 20.4, the interception rate of UV-A showed 94.3%, and that of UV-B showed 95.2%. After five-time washing, S.P.F. showed 14.3, the interception rate of UV-A showed 90.0%, and that of UV-B showed 93.2%. In the case of the silk fabric which was dyed but don't use mordant, after one time washing, S.P.F. showed 30.5, the interception rate of UV-A showed 95.9%, and that of UV-B showed 96.9%, after five-time washing, S.P.F. showed 31.0, the interception rate of UV-A showed 95.6%, and that of UV-B showed 96.7%.

Contamination of Chinese Cabbage with $^{85}Sr$, $^{103}Ru$ and $^{134}Cs$ Related to Time of Foliar Application ($^{85}Sr$, $^{103}Ru$, $^{134}Cs$의 엽면처리 시기에 따른 배추의 방사능 오염)

  • Choi, Yong-Ho;Lim, Kwang-Muk;Park, Hyo-Guk;Lee, Won-Yun;Lee, Chang-Woo
    • Journal of Radiation Protection and Research
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    • v.23 no.4
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    • pp.219-227
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    • 1998
  • A solution containing $^{85}Sr$, $^{103}Ru$ and $^{134}Cs$ was applied to Chinese cabbage in a greenhouse via foliar spraying at 5 different times during its growth. Interception of the applied activity by plant showed no difference among radionuclides and increased with decreasing time interval between application and harvest. The maximum interception factor observed was 0.87. Percentages of the intercepted activity remaining in the whole leaves at harvest varied $16{\sim}58%$ for $^{85}Sr$, $15{\sim}73%$ for $^{103}Ru$ and $33{\sim}64%$ for $^{134}Cs$, with application time and those for the inner leaves (without 6 outmost leaves) varied $2{\sim}35%$, $0.4{\sim}46%$ and $14{\sim}40%$, respectively. It was demonstrated that rain plays an important role in weathering loss of the activity. Tying the upper end of the plant prior to the last application lowered interception and remaining activity in the inner leaves by factors of $3{\sim}4$. Present results can be referred to in predicting the radionuclide concentration in Chinese cabbage and deciding counter-measures at the time of an accidental release from the nuclear installation.

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A Study on the Electromagnetic Transients in A Power System (전력계통의 전자과도현상에 관한 연구)

  • 김경철;강창원;이일무
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2001.11a
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    • pp.59-64
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    • 2001
  • Transient in an electrical system are generated by lightning and switching. This paper presents analysis of switching and lightning surge, and means of limiting the voltage magnification transient for high voltage power systems by using EDSA's EMTAP software package. One means of limiting the voltage magnification transient is to convert the end-user power factor correction banks to harmonic filters. An inductance in series with the power factor correction bank was used to decrease the transient voltage at the customer bus to acceptable levees. The interception of the impulse from the phase wire is fairly straight forward by properly installed surge arresters. The simulation shows that the addition of the surge arrester at the customer location can achieve a substantial reduction of the transient magnitude.

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Reduction of the Flow Accelerated Corrosion within Low Pressure Evaporator Connection Pipe by Interception of Hydrazine for Water Treatment (탈산소제 차단 수처리에 의한 배열회수보일러 저압증기발생기 연결배관내의 유동가속부식 저감)

  • Son, Byung-Gwan;Lee, Jae-Heon
    • Plant Journal
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    • v.9 no.4
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    • pp.26-30
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    • 2013
  • Based on case that HRSG low pressure steam generator tube was damaged by FAC in 500 MW A CCPP. This case analyzed the effect of application about the block of hydrazine water treatment which is applied for increasing dissolved oxygen. And also try to deduce the major factor of FAC Which is caused by lacking of dissolved oxygen of boiler feed system. After 1 year of water treatment, the figure of dissolved oxygen in the boiler feed water has increased from 0.15 ppb to 3~5 ppb and the figure of oxidation reduction potential has increased from -245 mV to 170 mV. And Iron content, the corrosion products by FAC has decreased from 18.5 ppb to 5~7 ppb. According to the result of experiment, we could able to confirm that the interception of hydrazine of water treatment is effective to reduce FAC.

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Effect of the climate change on groundwater recharging in Bangga watershed, Central Sulawesi, Indonesia

  • Sutapa, I Wayan
    • Environmental Engineering Research
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    • v.22 no.1
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    • pp.87-94
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    • 2017
  • This study was conducted to determine the effect of the climate change to the level of groundwater recharging. This research was conducted on the watershed of Bangga by using the Soil Water Balance of MockWyn-UB model. Input data compose of evapotranspiration, monthly rainfall, watershed area, canopy interception, heavy rain factor and the influence of climate change factors (rainfall and temperature). The conclusion of this study indicates that there is a decreasing trend in annual groundwater recharge observed from 1995 to 2011. The amount of groundwater recharge varied linearly with monthly rainfall and between 3% to 25% of the rainfall. This result implies that rain contributed more than groundwater recharge to runoff and evaporation and the groundwater recharge and Bangga River discharge depends largely on the rainfall. In order to increase the groundwater recharge in the study area, reforestation programmes should be intensified.

Development of Measurement System for Harmonic Analysis of Electric Equipment (전기설비의 고조파 분석을 위한 측정 시스템의 개발)

  • Yoo, Jae-Geun;Lee, Sang-Ik;Jeon, Jeong-Chay
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.259-261
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    • 2002
  • Recently, according to the spread of semiconductor applied technology like motor speed control contrivance, power conversion installation and so on, harmonic ingredients occurred in switching operation flow into a distribution system and increase voltage distortion of distribution system and bring on obstacles like damage, lowering of capability, false operation and so on of various electrical installation. So, in order to consider a countermeasure to limit occurrence quantity of harmonic source, harmonic interception and others, precision measurement and analysis on voltage, current, power, power factor, the each ingredient of harmonic order, the percentage of total harmonic distortion and so forth are needed. In this paper monitoring system to measure and analyze power quality connected with power harmonics was developed and it's performance is verified by measuring and analyzing three-phase voltage and current of R, S, T in the three-phase and four-wire system using the developed measurement system.

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Combining Four Elements of Precipitation Loss in a Watershed (유역내 네가지 강수손실 성분들의 합성)

  • Yoo, Ju-Hwan
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.200-204
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    • 2012
  • In engineering hydrology, an estimation of precipitation loss is one of the most important issues for successful modeling to forecast flooding or evaluate water resources for both surface and subsurface flows in a watershed. An accurate estimation of precipitation loss is required for successful implementation of rainfall-runoff models. Precipitation loss or hydrological abstraction may be defined as the portion of the precipitation that does not contribute to the direct runoff. It may consist of several loss elements or abstractions of precipitation such as infiltration, depression storage, evaporation or evapotranspiration, and interception. A composite loss rate model that combines four loss rates over time is derived as a lumped form of a continuous time function for a storm event. The composite loss rate model developed is an exponential model similar to Horton's infiltration model, but its parameters have different meanings. In this model, the initial loss rate is related to antecedent precipitation amounts prior to a storm event, and the decay factor of the loss rate is a composite decay of four losses.

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