• Title/Summary/Keyword: Water Cycle

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Recent(2008-2019) trend and expectations in future of the water reuse capacity based on the statistics of sewerage in Republic of Korea (최근(2008-2019년) 하수도통계 자료 분석 기반 국내 하수재이용량 예측)

  • Ma, Jeong-Hyeok;Jeong, Seongpil
    • Journal of Korean Society of Water and Wastewater
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    • v.35 no.6
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    • pp.477-487
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    • 2021
  • Due to the global climate change, Korean peninsula is has been experiencing flooding and drought severely. It is hard difficult to manage water resources sustainably, because due to intensive precipitation in short periods and severe drought has increased in Korea. Reused water from the wastewater treatment plant (WWTP) could be a sustainable and an alternative water source near the urban areas. In order to understand the patterns of water reuse in Korea, annual water reuses data according to the times and regional governments were investigated from 2008 to 2019. The reused water from WWTP in Korea has been mainly used for river maintenance flow and industrial use, while agricultural use of water reuse has decreased with time. Metropolitan cities in Korea such as Seoul, Busan, Daegu, Ulsan, and Incheon have been mainly used reused reusing water for river maintenance flow. Industrial water reuse has been limitedly applied recently for the planned industrial districts in Pohang, Gumi, Paju, and Asan. By using the collected annual water reuse data from the domestic sewerage statistics of sewerage, the optimistic and pessimistic future estimations of for future annual water reuse were suggested from 2020 to 2040 on a five year interval for every five years.

Viscum Album Var Hot Water Extract Mediates Anti-cancer Effects through G1 Phase Cell Cycle Arrest in SK-Hep1 Human Hepatocarcinoma cells

  • Cruz, Joseph Flores dela;Kim, Yeon Soo;Lumbera, Wenchie Marie Lara;Hwang, Seong Gu
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6417-6421
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    • 2015
  • Viscum album var (VAV) also known as mistletoe, has long been categorized as a traditional herbal medicine in Asia. In addition to its immunomodulating activities, mistletoe has also been used in the treatment of chronic hepatic disorders in China and Korea. There are numerous reports showing that VAV possesses anti-cancer effects, however influence on human hepatocarcinoma has never been elucidated. In the present study, hot water extracts of VAV was evaluated for its potential anti-cancer effect in vitro. SK-Hep1 cells were treated with VAV (50-400ug/ml) for both 24 and 48 hours then cell viability was measured by cell counting kit-8 (CCK-8). Flow cytometry analysis was used to measure the proportion of SK-Hep1 in the different stages of cell cycle. RT-PCR and Western blot analysis were conducted to measure expression of cell cycle arrest related genes and proteins respectively. VAV dose dependently inhibited the proliferation of SK-Hep1 cells without any cytotoxicity with normal Chang liver cell (CCL-13). Flow cytometry analysis showed that VAV extract inhibited the cell cycle of SK-Hep1 cells via G1 phase arrest. RT-PCR and Western blot analysis both revealed that cyclin dependent kinase 2 (Cdk2) and cyclin D1 gene expression were significantly down regulated while p21 was upregulated dose dependently by VAV treatment. Combined down regulation of Cdk2, Cyclin D1 and up regulation of p21 can result in cell death. These results indicate that VAV showed evidence of anti-cancer activity through G1 phase cell cycle arrest in SK-Hep1 cells.

Improvement of the Design Process of LID Retrofit Testbed for Effect Analysis of the Water Cycle (LID Retrofit 시범단지 설계 절차 개선)

  • Jung, Jong-Suk;Lim, Jung-Min;Hyun, Kyoung-Hak
    • Land and Housing Review
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    • v.8 no.4
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    • pp.267-274
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    • 2017
  • Since LID design process for the urban regeneration has not yet been established in Korea, this study was extablished in LID design process through reterauture reviews and expert opinions. But the extablished LID design processes have many limitations to be applied to proper LID facilities to the site because of not considering characteristics and water flow of the site. To solve the limitations of existing design processes, it is necessary for analysis of water flow through GIS analysis at the site. After analysis of water flow, it is important to find areas cut off water flow and to install LID facilities at those points. Through these considerations, this study present the improved LID design process to apply to urban regeneration.

Examination on High Vibration of Recirculation System for Feed Water Piping in Combined Cycle Power Plant (복합 발전소 주급수 재순환 배관계의 고진동 현상 및 대책)

  • Kim, Yeon-Whan;Kim, Jae-Won;Park, Hyun-Gu
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.04a
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    • pp.648-654
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    • 2011
  • The feed-water piping system constitutes a complex flow impedance network incorporating dynamic transfer characteristics which will amplify some pulsation frequencies. Understanding pressure pulsation waves for the feed-water recirculation piping system with cavitation problem of flow control valve is very important to prevent acoustic resonance. Feed water recirculation piping system is excited by potential sources of the shock pulse waves by cavitation of flow control valve. The pulsation becomes the source of structural vibration at the piping system. If it coincides with the natural frequency of the pipe system, excessive vibration results. High-level vibration due to the pressure pulsation affects the reliability of the plant piping system. This paper discusses the piping vibration due to the effect of shock pulsation by the cavitation of the flow control valves for the recirculation piping of feed-water pump system in combined cycle power plants.

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Practical Experiences with Corrosion Protection of Water Intake Gates in Mekong River

  • Phong, Truong Hong;Tru, Nguyen Nhi;Han, Le Quang
    • Corrosion Science and Technology
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    • v.7 no.6
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    • pp.328-331
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    • 2008
  • Corrosion behaviour of water intake gate steel structures with different protective measures was investigated. Five material alternatives were taken for investigation, including: imported and recycled stainless steel, carbon steel with hot zinc spraying, painting and composite coatings. Results of corrosion rate for carbon steel, SUS 304, hot zinc spray coats in three water systems of Mekong river basin (saline, blackish and fresh) were also presented. Corrosion rate of carbon steel decreased with decreasing salinity in the investigated water environments. Meanwhile, these values for zinc coated steel, behaved by another way. Environmental data for these systems were filed and discussed in relation with corrosion characteristics. Method of Life Cycle Assessment (LCA) was applied in materials selection for water intake gate construction. From point of Life Cycle Cost (LCA) the following ranking was obtained: Zinc sprayed steel < Recycled stainless steel < Composite coated steel < Painting steel < SUS 304 From investigated results, hot zinc spray coating has been applied as protective measure for steel structures of water intake systems in Mekong river basin.

The Strategy for the Advancement of Groundwater Management in Korea (국내 지하수 통합관리 선진화 전략)

  • Kang, Sunggoo;Kim, Jiwook;Choi, Yongjun;Park, Minyoung;Park, Hyunjin;Lee, Jinkwan
    • Journal of Soil and Groundwater Environment
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    • v.27 no.2
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    • pp.36-40
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    • 2022
  • To respond to rapidly changing water circumstances such as climate change, drought, etc., the korean government (MOE) established four advanced strategies for integrated groundwater management. The first strategy is watershed-based management of groundwater. The second strategy is total quantity management of groundwater including improvement of groundwater preservation area policy and procedure of investigation for groundwater influence area, additional construction of groundwater dam, installation of large-scale public wells, extention of spilled groundwater use. The third strategy is prevention of groundwater contamination including expansion of monitoring wells, introducing declaration of groundwater contamination. The last strategy is advancement of groundwater information management including integrated management of data, setting up a big-data based open platform. The above-mentioned four strategies will be reflected in the 4th National Groundwater Management Plan to secure implementation power, and it is expected to laid the foundation for advanced and rational groundwater management system.

Experimental study of dynamic interaction between group of intake towers and water

  • Wang, Haibo;Li, Deyu;Tang, Bihua
    • Earthquakes and Structures
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    • v.6 no.2
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    • pp.163-179
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    • 2014
  • Dynamic test with scaled model of a group of intake towers was performed to study the dynamic interaction between water and towers. The test model consists of intake tower or towers, massless foundation near the towers and part of water to simulate the dynamic interaction of tower-water-foundation system. Models with a single tower and 4 towers were tested to find the different influences of the water on the tower dynamic properties, seismic responses as well as dynamic water-tower interaction. It is found that the water has little influence on the resonant frequency in the direction perpendicular to flow due to the normal force transfer role of the water in the contraction joints between towers. By the same effect of the water, maximum accelerations in the same direction on 4 towers tend to close to each other as the water level increased from low to normal level. Moreover, the acceleration responses of the single tower model are larger than the group of towers model in both directions in general. Within 30m from the surface of water, hydrodynamic pressures were quite close for a single tower and group of towers model at two water levels. For points deeper than 30m, the pressures increased about 40 to 55% for the group of towers model than the single tower model at both water levels. In respect to the pressures at different towers, two mid towers experienced higher than two side towers, the deeper, the larger the difference. And the inside hydrodynamic pressures are more dependent on ground motions than the outside.

A Study on Typical Rates of Water-use for Primary School, Middle School and High School Facilities (초.중.고등학교 시설의 급수 사용량에 대한 연구)

  • Kim, Kyu-Saeng
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.12
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    • pp.802-807
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    • 2008
  • A Study on Typical Rates of Water-use for School Facilities has been carried out in this work. Water supply system is given much weight in school facilities. Therefore, it set up a basis efficiency using of water sources to calculate typical rates of water use. The results are summarized as follows; 1) On the whole, typical rates of water-use was founded out 15 L/stu. d in pirmary school, 10 L/stu. d in middle school and 30 L/stu. d in high school smaller than the existing it. It was rate of water-use change as season and Max. Rates of water-use was July. 2) I deem that school hours are 5 hour's in primary school, 7 hour's in middle school and 8 hour's in high school. It the concept of 1 hour that is lesson time 40 minutes and resting time 10 minutes in primary school, lesson time 45 minutes and resting time 10 minutes in middle school and lesson time 50 minutes and resting time 10 minutes in high school. 3) It is desired that we calculate the volume of pump and water tank throughout this concept and the size of water tank should be 1.5 times with taking peak load into consideration by this study on typical rate of water-use. 4) The amount of using water increases in gradually and I consider the life cycle of facilities is more than 10 years. As a result, I can forecast that the size will be insufficiency but I deem that if we devise a plan about parallel pumping on water tank space, we can cope with it. Also, it is expected that we can cut back the transport energy by controlling pump volume.

Hydrogen Prodution by Sulfur Thermochemical Water Splitting Cycle: Part 1. H2O-SO2-I2 Reaction and Separation (황 - 요오드의 열화학적 물분리에 의한 수소제조연구 Part I. 물-이산화황-요오드 반응 및 분리)

  • Lee, K.I.;Min, B.T.;Kwon, S.G.;Kang, Y.H.
    • Transactions of the Korean hydrogen and new energy society
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    • v.1 no.1
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    • pp.40-47
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    • 1989
  • The sulfur-iodine thermochemical water splitting process of GA(General atomic) cycle was studied to produce hydrogen from water by $H_2-I_2-SO_2$ reactions. The experimental scale was 500g based on iodine. The reaction took 100 minutes, products could be separated two liquid phases due to their density difference:HI solution had a density of 2.39~2.61g/cc, and $H_2SO_4$ solution had 1.37~1.38g/cc. The condition of reaction was when weight ratio of $I_2/H_2O$ was 2/1 resulting in good phase separation and productivity.

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Research about point adhesion disconnection type non-exposure composition waterproof method of construction development that use embossing PVC sheet (엠보싱 PVC 시트를 이용한 부분절연(部分絶緣) 블록형 옥상(屋上) 비노출 복합방수(複合防水)공법 개발(開發)에 관(關)한 연구(硏究))

  • Wi, Tae-Hwan;Kang, Hyo-Jin;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.11a
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    • pp.37-40
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    • 2003
  • This present paper mainly contains adhesion part disconnection type exposure composition waterproof method using embossing PVC sheet. The existing polymer resin coating and sheet waterproofing construction method have, however, some weak point such as being decrease life cycle of concrete with water leaking from materials be affected by crack and movement dash bond concrete through the whole-adhere construction. Above the reason, this paper has particular method increasing crack-defending performance from stress occurred concrete movement by part disconnection, adds maintain waterproofing performance subordinate sheet, that can be contributed a convenience of maintenance which is decreasing industrial waste and repair construction cycle through the part repair in case of leaking water.

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