• Title/Summary/Keyword: 평형시간

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Development of Steady State Isotope Concentration Analysis Code for Molten Salt Reactor Using Variable Reprocess Time Constant (가변 재처리 시간상수를 고려한 용융염핵연료 원자로 평형핵종농도분석 코드 개발)

  • 원성희;조재국;임현진;김태규;윤정선;오세기
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1999.05a
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    • pp.107-112
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    • 1999
  • AMBIDEXTER(Advanced Molten-salt Break-even Inherently-safe Dual-mission Experimental & Test Reactor) 핵연료계통은 Th/$^{233U}$ 불화용융염으로 구성되어 있으며, 핵분열생성물질의 운전중 연속재처리가 가능하여 운전상태에 따라 원자로내 연료물질의 농도분포를 정확하게 계산하는 것은 원자로 설계에 있어 주요 기술이다.(중략)

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공액근사개념 및 변위장 반복계산에 의한 국부응력장 개선 연구

  • 송기남
    • Proceedings of the Korean Nuclear Society Conference
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    • 1997.05b
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    • pp.495-502
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    • 1997
  • 변위형 유한요소해에 기초하고 공액근사개념 및 Loubignac의 변위장 개선방법을 국부영역에 적용하여 국부영역에서의 응력장의 정확도를 향상시킬 수 있는 방법을 제안하였다. 제안된 방법에서 계산된 국부영역의 응력장은 전체영역에 대한 응력장 개선 결과에 근접하며 유한요소 평형방정식을 잘 만족하친 있을 뿐만 아니라 수회 이내의 반복계산내에 수렴하고 있어서 계산시간이 크게 줄어들 수 있어서 국부영역에 대한 상세응력해석에 적절하게 이용될 수 있다.

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A Study on the Removal Efficiency of a TEDA Impregnated Charcoal Bed for Methyl iodide under Humid Conditions (습윤 조건하에서 TEDA함침탄소층에 의한 Methyl Iodide 제거효율에 관한 연구)

  • Won Jin Cho;Soon Heung Chang
    • Nuclear Engineering and Technology
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    • v.16 no.3
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    • pp.161-168
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    • 1984
  • The adsorption model to predict the time dependent removal efficiency of methyl iodide by triethylenediamine (TEDA) impregnated charcoal bed under humid condition is proposed. Under humid conditions, the reduction of equilibrium adsorption capacity and effective pore diffusivity is considered. The predicted values are compared with the experimental results.

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Effect of Accelerated Storage on the Microstructure and Water Absorption Characteristics of Korean Adzuki Bean (Vigna angularis L.) Cultivar (팥의 가속화 저장에 따른 미세구조 및 수분흡수 특성)

  • Jieun Kwak;Seon-Min Oh;You-Geun Oh;Yu-Chan Choi;Hyun-Jin Park;Suk-Bo Song;Jeong-Heui Lee;Jeom-Sig Lee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.68 no.3
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    • pp.167-174
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    • 2023
  • This study investigated the microstructure and water absorption characteristics of the Korean adzuki bean (Vigna angularis L.) cultivar under accelerated storage. The germination rate, acid value, redness (a*), and yellowness (b*) values showed no significant differences after three months of storage compared to pre-storage under low temperatures (4℃). However, a statistically significant difference was observed under accelerated high temperatures (45℃). In particular, after storage for three months, the germination rate and acid value were 0% and 33.63 mg KOH/100g, respectively, under accelerated high temperatures. After storage for three months, the holes, hilum damage, and spaces between the seed coat and cotyledon shortened the time and speed of water absorption under accelerated high temperatures compared to that under low temperatures. Conversely, further research is required to investigate the reason for the low rate of parallel water absorption.

Finite Element Analysis of Underground Electrical Power Cable Structures Considering the Effects of Construction Sequence (시공단계별 영향을 고려한 터널 전력구의 유한요소해석)

  • Kim, Sun-Hoon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.2
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    • pp.147-155
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    • 2013
  • In this paper structural analysis of underground electrical power cable structures which is excavated below the surface of the earth in the downtown area is carried out considering the effect of construction sequence. There are many various life-line facilities below the surface of the earth in the downtown area. MPDAP was used for finite element analysis of underground electrical power cable structures. Three typical sections are simulated by finite element models. Unbalanced equilibrium problems may be occurred when conventional finite element procedures were used for simulation of tunnel excavation. Therefore equilibrium perturbation concept was applied to solve these problems. The effects of time-dependent deformations in advancing tunnel excavation are considered in the stages of construction sequences as using the load distribution factor. It is shown that values of maximum displacement of both soil and rock surrounding underground electrical power cable structures obtained by our numerical studies are less than allowable values.

A Quasi-Steady Model for Sedimentation and Flushing of Reservoirs (저수지 퇴배사 모의를 위한 준정류모형)

  • Choi, Sung-Uk;Choi, Seong-Wook
    • Journal of Korea Water Resources Association
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    • v.45 no.2
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    • pp.217-227
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    • 2012
  • This paper presents a quasi-steady model for numerical simulations of reservoir sedimentation and reservoir flushing. The quasi-steady model is based on the assumption that the flow is steady with time-dependent stream morphology change. This is reasonable because stream morphology changes over a long period, while the flow changes rapidly. The proposed model is first applied to two laboratory experiments for reservoir sedimentation. The channel is shown to be adjusted to new sediment supply at the upstream by changing both the flow depth and slope. Simulated water surface and bed profiles compare favorably to measured data. The model is also applied to reservoir flushing. Good agreement between simulated and measured data is not obtained due to time variation of outflow generated to facilitate the flushing in the experiment. Finally, relationships for equilibrium flow depth and bed slope are proposed and tested through numerical experiments.

Copper Solubility in Al2O3-CaO-SiO2-MgO Slag (Al2O3-CaO-SiO2-MgO계 슬래그 중 Cu의 용해도)

  • Han, Bo-Ram;Kim, Eung-Jin;Sohn, Ho-Sang
    • Resources Recycling
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    • v.23 no.1
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    • pp.33-39
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    • 2014
  • In this study, the solubility of Cu, which is a main metal component of wasted PCB, in $CaO-SiO_2-Al_2O_3-MgO$ slag system was investigated. Each 20 grams of Cu chips and the quaternary slag manufactured was placed in an carbon crucible and melted for 10 hours in the temperature between 1673 K and 1825 K to confirm the equilibrium state. The oxygen partial pressure was controlled by the ratio of CO and Ar gas in the range of $10^{-17.23}$ to $10^{-15.83}$ atm. The concentration of Cu in the slag increased with increasing oxygen partial pressure, slag basicity, and MgO content in the slag. The concentration of Cu in the slag decreased with increasing temperature. The Cu dissolution reaction in the slag is an exothermic reaction.

The Design Charts for Soil Nailing Slopes Through Limit Equilibrium Method (한계평형해석을 사용한 Soil Nailing보강사면의 설계도표의 제안)

  • Kim, Hak-Moon;Jang, Kyung-Jun;Seo, Jin-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.10
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    • pp.2794-2802
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    • 2009
  • Soil nailing method is widely used in reinforcing slopes and excavating earth. The analysis of nail-reinforced slopes, generally require complicated computer programs. The purpose of this paper is suggest, Soil stability Chart for nailed slopes which are very useful for pre-design, rapidly design, and final check. Three slope types, three nail lengths and three nail angles are selected for the stability analysis by using limit equilibrium method form Bishop and French. From the above results, this study propose the reinforced design charts for examine the necessity of reinforcement can be examined. The suggested stability chart and Taylor's Slope Stability Chart, showed similar safety factors. This Soil Nailing design charts can provide the solutions for necessity of reinforcement, economical of nail's length ratio and installation angle as well.

Characterization of Chromium(VI) Adsorption onto Silk Fabrics (견직물에의 크롬(VI)의 흡착 특성)

  • 김규범;진영길
    • Journal of Sericultural and Entomological Science
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    • v.38 no.1
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    • pp.25-30
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    • 1996
  • The adsorption mechanism of Chromium(VI) uptake in silk fibroin fibers was discussed. The adsorption equilbrium of Chromium(VI) is significantly influenced by the initial adsorption rate and it showed 52% of the equilibrium uptake. The Chromium(VI) uptake by silk fibroin in increased with the acidic range of pH, which react upon Chromium(VI) oxidations. The enthalpy change in the Chromium(VI) on the temperatures, $\Delta$H, was found to be 39.7 KJ.mol-1, It means that the Chromium(VI) adsorption proceeds via a certain complex chemical reaction and the Chromium complex was found to be coordinated with carbonyl group of amides from the result of infrared spectra. The chroming of silk fibroin fibers in moderated in the conditions of 5$0^{\circ}C$, pH 2.4, and 3 hours, which prevent from the loss of physical properties. The equilibrium adsorption is attained at 5 X 10-3M of Chromium(VI) solutions.

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Sterilization and ecofriendly neutralization of seawater using electrolysis (전기분해에 의한 해수살균 및 친환경 중화에 관한 연구)

  • Yang, Jeong-Hyeon;Choi, Jong-Beom;Yun, Yong-Sup
    • Journal of Advanced Marine Engineering and Technology
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    • v.41 no.3
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    • pp.276-280
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    • 2017
  • In this study, we investigated the effect of sterilization and the neutralization of treated ballast water using seawater electrolysis. The electrolysis apparatus has a cation-selective membrane for passing the cation and a titanium electrode in each cell. We examined the sterilization effect after an incubation period of 24 hr. The oxidation reaction during electrolysis caused, the solution to become strongly acidic due to the generation of a hydroxyl group, and the oxidation reduction potentials(ORP) was increased to 800 - 1200mV. After the reduction reaction, the solution became alkaline(pH 9 - 12), and ORP was decreased to - 900 - - 750 mV. It might be possible to control the pH of ballast water through electrolysis. In addition, we demonstrated the effects of sterilization of ballast water containing generated hypochlorous acid using electrolysis under high ORP condition.