• Title/Summary/Keyword: Water movement

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Estimation of Return Flow Rate According to Demand Water Movement on Geum River (금강수계의 용수이동에 의한 회귀율 추정)

  • Maeng, Seung-Jin;Lee, Sang-Jin;Hwang, Man-Ha;Koh, Ick-Hwan;Kim, Man-Sik
    • Proceedings of the KAIS Fall Conference
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    • 2007.11a
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    • pp.367-370
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    • 2007
  • 한국수자원공사에서 개발한 유출모의 모형인 RRFS의 입력자료로 사용되는 소유역별 각 용수에 대한 회귀율은 생공용수의 경우에는 65%, 농업용수의 경우에는 35%로 하여 일괄적으로 입력되어 있으나 이러한 값은 대략적으로 추정된 값이다. 따라서 본 연구에서는 금강수계내 전체에 대한 용수체계도를 대청댐 상류, 청주권, 대전권, 대청댐 하류 및 하구언권으로 구분하여 각 권역별로 작성하여 유출체계에 의한 메커니즘을 도시하였다. 본 연구에서는 체계적인 용수이용별 물이용수급현황 분석을 통해 물이용현황을 파악하는 것에 목적을 삼고 용수계통도 작성을 통한 권역별 용수체계를 분석하고자 하였다. 금강유역내 총 14개의 소유역에 대한 용수계통도 작성을 통해 용수수급현황을 분석하고, 궁극적으로 용수수급현황도를 작성하고자 각 권역별 하천 수계현황 조사, 용수사용현황 조사, 주요 용수시설물 현장조사 및 용수계통도를 작성하였다.

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Removal of Flooding in a PEM Fuel Cell at Cathode by Flexural Wave

  • Byun, Sun-Joon;Kwak, Dong-Kurl
    • Journal of Electrochemical Science and Technology
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    • v.10 no.2
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    • pp.104-114
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    • 2019
  • Energy is an essential driving force for modern society. In particular, electricity has become the standard source of power for almost every aspect of life. Electric power runs lights, televisions, cell phones, laptops, etc. However, it has become apparent that the current methods of producing this most valuable commodity combustion of fossil fuels are of limited supply and has become detrimental for the Earth's environment. It is also self-evident, given the fact that these resources are non-renewable, that these sources of energy will eventually run out. One of the most promising alternatives to the burning of fossil fuel in the production of electric power is the proton exchange membrane (PEM) fuel cell. The PEM fuel cell is environmentally friendly and achieves much higher efficiencies than a combustion engine. Water management is an important issue of PEM fuel cell operation. Water is the product of the electrochemical reactions inside fuel cell. If liquid water accumulation becomes excessive in a fuel cell, water columns will clog the gas flow channel. This condition is referred to as flooding. A number of researchers have examined the water removal methods in order to improve the performance. In this paper, a new water removal method that investigates the use of vibro-acoustic methods is presented. Piezo-actuators are devices to generate the flexural wave and are attached at end of a cathode bipolar plate. The "flexural wave" is used to impart energy to resting droplets and thus cause movement of the droplets in the direction of the traveling wave.

Review of Functional Kinematic Analysis for Clinical Application of Upper Limb (사지경근(上肢經筋)의 임상적 응용을 위한 기능적인 움직임 분석에 대한 고찰)

  • Hong, Seo-Young;Song, Yeun-Kyung;Lim, Hyung-Ho;Cho, Hyun-Chol
    • The Journal of Korea CHUNA Manual Medicine
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    • v.5 no.1
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    • pp.251-262
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    • 2004
  • The purpose of this article is to contribute to the knowledge of meridian muscles and myofascial meridians of upper limb that relate with normal movement and getting a glass of water. We researched on analysis of normal articular movement and the related muscles. In addition this article is suggested to study about the Therapy with apply meridian muscles and myofascial meridian lines to upper limb's motor disturbance.

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Synthesis and Characterization of Glold Nanofluid Prepared by the Solution Plasma Processing (용액 플라즈마 공정을 이용하여 제조된 금 나노유체의 특성평가)

  • Heo, Yong-Kang;Lee, Sang-Yul
    • Journal of Powder Materials
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    • v.17 no.4
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    • pp.342-346
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    • 2010
  • In the present work, water-based gold nanofluids were synthesized by the solution plasma processing (SPP). The size distribution and the shape of gold nanoparticles in the nanofluids were investigated using high resolution transmission electron microscopy (HR-TEM). The dispersion stability of gold nanofluids was characterized using zeta potential, as well. The thermal properties of gold nanofluids were measured by utilizing lambda measurement device. Nanofluids containing nanoparticles with $64.0{\pm}42.1\;nm{\sim}18.10{\pm}5.0\;nm$ in diameter were successfully synthesized. As diameter of nanoparticles decreased, dispersion stability of nanofluids increased and the enhanced ratio of thermal conductivity increased. The nanofluid with nanoparticles of $18.10\;{\pm}\;5.0\;nm$ in diameter showed approximately 3% improvement in thermal conductivity measurement and this could be due to the enhanced Brownian movement.

기름 유출로 인한 토양 및 지하수의 오염

  • Kim Dong-Jin;Yang Jae-Eui;Yu Jin-Yeol;Kim Hui-Gap;Kim Gi-Dong
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2006.04a
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    • pp.424-427
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    • 2006
  • Soil contamination with petroleum oil around a military army was investigated. It showed that soils of a riverside highland, an entrance of the military army, and nearby roads were contaminated with total petroleum hydrocarbons (TPH) released from the military army to the depth of approximately 2 m. The measured concentrations were as high as 15,277 mg/kg. A wide range of soil in the riverside highland was contaminated by the movement of oil to the surface soil, which occurred with the vertical movement of groundwater table caused by the change of river water level and groundwater level. Spilled petroleum oil components were released into Wonju Stream by the increase of hydraulic conductivity and the groundwater flow.

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Analytic Modeling of the Xenon Oscillation Due to Control Rod Movement

  • Song, Jae-Seung;Cho, Nam-Zin;Zee, Sung-Quun
    • Nuclear Engineering and Technology
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    • v.31 no.1
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    • pp.80-87
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    • 1999
  • An analytic axial xenon oscillation model was developed for pressurized water reactor analysis. The model employs an equation system for axial difference parameters that was derived from the two-group one-dimensional diffusion equation with control rod modeling and coupled with xenon and iodine balance equations. The spatial distributions of nu, xenon, and iodine were expanded by the Fourier sine series, resulting in cancellation of the flux-xenon coupled non-linearity. An inhomogeneous differential equation system for the axial difference parameters, which gives the relationship between power, iodine and xenon axial differences in the case of control rod movement, was derived and solved analytically. The analytic solution of the axial difference parameters can directly provide with the variation of axial power difference during xenon oscillation. The accuracy of the model is verified by benchmark calculations with one-dimensional reference core calculations.

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Modeling of rain-wind induced vibrations

  • Peil, Udo;Nahrath, Niklas
    • Wind and Structures
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    • v.6 no.1
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    • pp.41-52
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    • 2003
  • Rain-wind induced vibrations of cables are a challenging problem in the design of cable-stayed bridges. The precise excitation mechanism of the complex interaction between structure, wind and rain is still unknown. A theoretical model that is able to accurately simulate the observed phenomena is not available. This paper presents a mathematical model describing rain-wind induced vibrations as movement-induced vibrations using the quasi-steady strip theory. Both, the vibrations of the cable and the movement of the water rivulet on the cable surface can be described by the model including all geometrical and physical nonlinearities. The analysis using the stability and bifurcation theory shows that the model is capable of simulating the basic phenomena of the vibrations, such as dependence of wind velocity and cable damping. The results agree well with field data and wind tunnel tests. An extensive experimental study is currently performed to calibrate the parameters of the model.

A design of the Artwork for the Atrium (아트리움을 위한 조형물 디자인)

  • Lee, Ran-Pyo
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2005.05a
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    • pp.263-266
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    • 2005
  • This work aims at the design of the artwork for the atrium of a furniture department store. In complying with the request of the building owner I have established the basic concept, 'silence in movement - movement in silence', to design a artwork, which not only can make the various atmospheres in the store to the unique one, but also arrange an emotional stability for the visitors. Most exhibited furnitures are those that demand particular interests from the visitors, and the exhibition scale is enormous. So it is difficult to sustain the continuous inspiration and the emotional stability, and also it is hard to make the store have the consequent image. This problem can be resolved through the installation of the artwork that can evoke the visitor to the abundant sensitive receivability. The materials, which are used tp express the basic concept, are water, concrete, light and aluminium that represent a unified harmony in a contrast each other.

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A Study on Movement Characteristics Analysis of Debris Accumulation at Flood (홍수시 유송잡물 이동 특성 분석에 관한 연구)

  • Oh, Chae-Yeon;Jun, Kye-Won;Yoon, Young-Ho
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.707-710
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    • 2008
  • Recently, a rivers' bridge that locate on among the mountains area is destroyed by debris accumulation and debris flow, because of frequent occurrence of typhoon and a localized torrential downpour. therefore a river make a part of dam's effect. Actually, this situation gives damages like inundation of a bridge upper stream area's. Generally, It the main cause of the occurrence route of the debris accumulation is that outbreaks of driftwood and debris flow because of landslide, that occurred by severe rain storm. Also, a lot of debris are occurred when big flood come up during long period at this time, this kind of debris accumulation remove to other place, in several, and specially, debris accumlation move to the place where the depth of water is deep and velocity is fast river center. According to these kind of fact, this research put in effect and analyze that movement characteristic's numerical simulations of debris accumulation at flood according to a domestic outside literature investigation, on-site monitoring survey and parameter scenario which comes out through the hydraulic modeling analysis.

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DEVELOPMENT OF NANO-FLUID MOVEMENT MEASURING DEVICE AND ITS APPLICATION TO HYDRODYNAMIC ANALYSIS OF DENTINAL FLUID (미세 물 흐름 측정장치의 개발과 상아세관액의 수력학에의 응용)

  • Lee, In-Bog;Kim, Min-Ho;Kim, Sun-Young;Chang, Ju-Hea;Cho, Byung-Hoon;Son, Ho-Hyun;Back, Seung-Ho
    • Restorative Dentistry and Endodontics
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    • v.33 no.2
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    • pp.141-147
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    • 2008
  • This study was aimed to develop an instrument for real-time measurement of fluid conductance and to investigate the hydrodynamics of dentinal fluid. The instrument consisted of three parts; (1) a glass capillary and a photo sensor for detection of fluid movement, (2) a servo-motor, a lead screw and a ball nut for tracking of fluid movement, (3) a rotary encoder and software for data processing. To observe the blocking effect of dentinal fluid movement, oxalate gel and self-etch adhesive agent were used. BisBlock (Bisco) and Clearfil SE Bond (Kuraray) were applied to the occlusal dentin surface of extracted human teeth. Using this new device, the fluid movement was measured and compared between before and after each agent was applied. The instrument was able to measure dentinal fluid movement with a high resolution (0.196 nL) and the flow occurred with a rate of 0.84 to 15.2 nL/s before treatment. After BisBlock or Clearfil SE Bond was used, the fluid movement was decreased by 39.8 to 89.6%.