• Title/Summary/Keyword: Material circulation

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Comprehensive Assessment of the Utilization System for Marine Biomass Resources Using Exergy Flows (엑서지 흐름을 이용한 해양 생물체 자원 이용 시스템의 포괄적인 평가)

  • Kuroda, Kana;Nakatani, Naoki;Otsuka, Koji
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.15 no.2
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    • pp.126-132
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    • 2012
  • In recent years, serious environmental problems occur in coastal area due to high pollution loads from human activity in land. Marine biomass utilization system therefore has been proposed to prompt material circulation between land and sea. Comprehensive assessment is necessary to determine that the proposed system is suitable and sustainable. This study introduces thermodynamic concept exergy, which expresses energy quality, to describe material and energy flowing in the material circulation system. This study presents material, energy and exergy flows in the material circulation system at Sakai city located in the middle of Osaka in Japan. It is found that exergy helps a better understanding of what is a key role is in exergy-efficient material circulation system.

A study on the Optimal Condition for Application with Extracorporeal Membrane Oxygenation (ECMO 시스템 적용을 위한 최적화 조건에 관한 연구)

  • Kim, Jae-Yeol;Song, Min-Jong;You, Sin;Ma, Sang-Dong;Kim, Chang-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.09a
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    • pp.13-18
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    • 2001
  • The ECMO system, including umbilical cord and membrane type oxygenator was connected with extracorporeal circulation unit, was applied to the fetus growth model of goat. The maximum survival time of goat fetus was 48 hours. Average blood rate for the extracorporeal circulation was $223{\pm}15.2 ml/min.$ The survival time of fetus was deeply related to body temperature, blood circulation and water temperature, anesthetized time, and fetus weights. Extern variables that are composed of anesthetized time, fetus weights, change of hemoglobin, circuit pressure, related to the survival time for fetus corrected the problem of previous ECMO model that is controlled by roller pump. It is directly delivered to heart on load. Applying the results from new ECMO model, further research will provide to the system of ECMO for human.

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Analysis of Two Phase Natural Circulation Flow in the Reactor Cavity under External Vessel Cooling (원자로용기 외벽냉각시 원자로공동에서 이상유동 자연순환 해석)

  • Park, Rae-Joon;Ha, Kwang-Soon;Kim, Sang-Baik;Kim, Hee-Dong
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.2141-2145
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    • 2004
  • As part of study on thermal hydraulic behavior in the reactor cavity under external vessel cooling in the APR (Advanced Power Reactor) 1400, one dimensional two phase flow of steady state in the reactor cavity have been analyzed to investigate a coolant circulation mass flow rate in the annulus region between the reactor vessel and the insulation material using the RELAP5/MOD3 computer code. The RELAP5/MOD3 results have shown that a two phase natural circulation flow of 300 - 600 kg/s is generated in the annulus region between the reactor vessel and the insulation material when the external vessel cooling has been applied in the APR 1400. An increase in the heat flux of the inner vessel leads to an increase of the coolant mass flow rate. An increase in the coolant outlet area leads to an increase in the coolant circulation mass flow rate, but the coolant inlet area does not effective on the coolant circulation mass flow rate. The change of the lower coolant outlet to a lower position affects the coolant circulation mass flow rate, but the variation trend is not consistent.

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Simplified Numerical Model of the Wind-driven Circulation with Emphasis on Distribution of the Tuman River Solid Run-off

  • Vanin, N.S.;Moshchenko, A.V.;Feldman, K.L.;Yurasov, G.I.
    • Ocean and Polar Research
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    • v.22 no.2
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    • pp.81-90
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    • 2000
  • Supposed construction of a large port in the mouth of Tuman River requires careful examination of possible unfavorable ecological consequences for the Far Eastern Federal Marine Reserve. Since the Tuman River is the largest source of suspended material and possible contaminants flowing into the sea, and in order to understand how this material is allocated in the coastal zone, analyses are needed to check possible pathways of water transport and circulation system in the region. Linearized shallow water equations were used for numerical simulation of the wind-driven circulation to the north off the Tuman River mouth. The model results satisfactorily agreed with in situ data. The model circulation patterns are largely dependent on the wind direction and are conformed by the distribution of bottom sediments, and by the location of organic carbon and some pollutants accumulation zones. The most unfavorable situation for the Marine Reserve is the case of the southwesterly wind; even with quite moderate wind, the waters polluted by the run-off from the Tuman River can attain the south section of the Marine Reserve during the diurnal period.

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The Concept of Artificial Liver Support by Using the Extracorporeal Circulation System

  • Cheon, Min-Woo
    • Transactions on Electrical and Electronic Materials
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    • v.16 no.1
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    • pp.25-28
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    • 2015
  • In this study, a basic research on artificial liver was performed for its application to people on the waiting list of liver transplant or patients with hepatic insufficiency. Artificial livers are generally classified into mechanic type, bioartificial type, and hybrid type. An extracorporeal circulation device was examined herein, which is indispensable in the application of an artificial liver, for its effectiveness in supporting the recovery of liver functions. Extracorporeal circulation system is a treatment and life-support system which sends out the patient's blood, removes toxicity by various methods, and then sends the blood back to the interior of the body. This study used an extracorporeal circulation system which enables the Plasma Perfusion by CVVH method, and applied the program of Bioateco corp. Animals with acute hepatic insufficiency were produced to apply the extracorporeal circulation device. As a result, their ammonia, bilirubin, SGOT, SGPT, and bile acid levels rose, confirming the liver function restoration in the experimental animals.

A Simulation on the Two-Phase Flow Characteristics in Gas Bubble Driven Circulation Systems (Gas Bubble Driven Circulation Systems에서의 이상유동 특성의 시뮬레이션)

  • 최청렬
    • Journal of the Korea Society for Simulation
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    • v.7 no.2
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    • pp.17-32
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    • 1998
  • The flow fields in Gas Bubble Driven Circulation Systems were numerically analyzed. In various gas flow rate and bubble size, the flow characteristics were predicted. Eulerian-Eulerian approach was used for the formulation of both the continuous and dispersed phases. The modification of the general purpose computer program PHOENICS code was employed to predict the mean flow fields, turbulent characteristics, gas dispersion, volume fraction. The predicted shows very satisfactory agreement with experimental results for all regions of ladle. The results are of interest in the design and operation of wide variety of material processing.

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A Study on the Space Composition and the Visitor Circulation of the Theme Museum in Jeju (제주지역 테마박물관의 공간구성과 관람동선체계에 관한 연구)

  • Park, Chul-Min;Hong, Ji-Ho
    • Journal of the Korean Institute of Rural Architecture
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    • v.10 no.2
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    • pp.53-61
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    • 2008
  • There are many ways to know the social and cultural level of each country. Among them, a theme museum are not only the best place to understand the history, the life style and the culture level. This thesis has the purpose to provide the basic material through analyzing the space composition and the visitor circulation of the theme museum and understanding the relativity of them so that the new theme museums can be designed in the right direction. So I chose the independence museum that opened with in recent 10 years, finally middle & small size's theme museum were selected. The results from the case study are as follow. Firstly, according to a result of analyzing the characteristics of space composition with the ratio of each part's area, space composition of each museum is mainly for the exhibition part, but rarely for the education part. Secondly, theme museums in Jeju have the limit of diversity of circulation method because they have not the free circulation method. Thirdly, the characteristics of space composition is divided into basic type, center-hall enter type, around the center-hall type and guidance type. Fourthly, by analyzing the characteristics of space composition and circulation method of traffic line, it's realized that selective circulation method was applied to basic type and center-hall enter type, and guidance circulation method was applied to around the center-hall type and guidance type.

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Effects of Paddle Wheel on Water Circulation in Shrimp Culture Ponds (축제식 대하양식장에서 수차의 순환기능)

  • 강윤호
    • Journal of Aquaculture
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    • v.14 no.1
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    • pp.43-50
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    • 2001
  • To study the effect of paddle wheel on water circulation, velocity components were measured in shrimp ponds both along the longitudinal direction from a single paddle wheel and at 25 grid points of two ponds, which have mean water depth of 1.2m and aspect ratio (length/width) 1.05 and 0.68, respectively. An analysis of factors related to water quality and circulation showed that I) a single paddle wheel has an effective distance of 33m for de-stratification, 16m for particulate suspension and 25m for removal of organic material, dispersion of DO and prevention of bed sediment disturbance and ii) with doubling the number of paddle wheels at the pond corners, the flow speed increased by 13% over the ponds, while it reduced by 8.5% around the pond centres. Contrary to expectation, increasing the number of paddle wheel did not generate strong circulation around the pond centre and improve water quality.

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A Numerical Simulation of Residual Current and Material Transportation in Hiroshima Bay, Japan (황도만에서의 잔차류와 물질소송의 수치모형실험)

  • 이인철
    • Journal of Ocean Engineering and Technology
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    • v.15 no.1
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    • pp.45-51
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    • 2001
  • In order to clarify the seasonal variation of the residual current and the material transportation process in Hiroshima Bay, JAPAN, the real-time simulation of residual current and particle tracking by using the Euler-Lagrange model were carried out. The calculated tidal current, water temperature, and salinity showed good agreement with the observed ones. The residual currents showed a southward flow pattern at the upper layer, and a northward flow pattern at the lower layer. The flow structure of the residual current in Hiroshima Bay is an estuarine circulation affected by density flow and wind driven current. The residual current plays an important role of material transportation in the bay.

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Performance of Liquid-Cooled Cold Plates for Multiple Heat Sources in a Humanoid Robot (인간형 로봇 내부의 다중 열원에 대한 수냉식 냉각판의 성능)

  • Karng, Sarng-Woo;Kim, Seo-Young;Moon, Jong-Min;Hwang, Kyu-Dae;Rhee, Gwang-Hoon
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2053-2058
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    • 2008
  • It was investigated thermal performances on two array types of a serial circulation and a two-way parallel circulation for six water-cooled cold plates covered with non-metallic material (polycarbonate, PC) to reduce weight of the cooling devices for humanoid robot cooling. Six cold plates attached on $10{\times}10\;mm^2$ copper base : $0.5{\times}0.5\;mm^2$ pin-finned surfaces of 1.5 mm high with 0.5 mm array spacing, was mounted on six copper heating blocks with isothermal conditions of $50{\sim}90^{\circ}C$, respectively. In order to compare thermal characteristics according to two circulation types, the surface temperatures of heating blocks and the cooling water temperatures at inlets and outlets of cold plates were measured. From the results, it was found that a two-way parallel circulation was better performance than a serial circulation in terms of total thermal resistance, total heat transfer rate, and surface temperature rises from $1^{st}$ heating block to last one for six multiple cold plates.

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