• Title/Summary/Keyword: current shroud

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Analysis of Flow Field Characteristics Inside a Shroud for Rotor Positions (로터 위치에 따른 쉬라우드 내부 유동장 특성 분석)

  • Bak, Da In;Han, Seok Jong;Lee, Uk Jae;Lee, Sang Ho;Choi, Hyuk Jin;Im, Jong Seok
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.32 no.1
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    • pp.48-54
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    • 2020
  • Numerical analysis was carried out to analyze the flow fields and mechanical output of a rotor for various positions and inlet flow rates in a shroud, and it was compared with experimental data. Rotor and seawater current largely affects the flow field characteristics in the shroud system. Especially the mechanical output of the rotor increased with axial position near the center of the cylinder, and it gradually decreased close to the entrance and exit. Also, the rotor output increased with the inlet velocity. Axial and angular momentum of flow along the cylinder region rapidly increased and reached a peak, and then decreased as it passed through the rotor, while there was no significant change in the cylinder region. It is expected that these results can be used as applicable design data for the development of the tidal power generation system.

The Analysis of Sensibillity Preference of Women's Shroud Design (여자수의 디자인에 대한 감성선호도 분석)

  • Lee, Choon-Hee;Kim, Jong Moo
    • Journal of the Korea Fashion and Costume Design Association
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    • v.17 no.4
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    • pp.15-29
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    • 2015
  • Apart from keeping the body pleasant and protecting it from the environment, the purpose of clothing is to express one's sensibility, sense of belonging, status, and aesthetic sense. In the past, hanbok was also used to express status and class with the colors and the types and according to the times, the forms of hanbok has changed. Nowadays, people choose and wear hanbok that suits their tastes or purposes and various types of hanbok that considered pros and cons of it are now disseminated. Given this reality, traditional shrouds that are worn by the dead should also be designed newly to fit the modern trend. This research aims to analyze how people's sensibility preferences change on the traditional shrouds and the modern shrouds that are designed to fit the current trend. To see the change, this research analyzes sensibility preferences by using Semantic Differential Method on 4 modern shrouds that are used in preceding research and 1 traditional shroud. The survey was answered by total of 130 ordinary people in groups of 26 people in 5 groups who reside in Seoul and Kyungkhi province. As the result of the analysis, firstly, people preferred "high quality", "elegant", and "Korean" sensibility words for modern shrouds 1, 2, 3, and 4. Secondly, on traditional shroud, "uncomfortable", "neutral-elegant", "neutral-Korean", and "neutral-quality" that is closer to low quality sensibility words are preferred. Thirdly, "modest" and "extravagant" did not show any statistically significant difference. I hope this research can provide basic data that can be used to understand and comprehend on people's sensibility preference about shroud designs.

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Experimental Performance Analysis using a Compact Scale Model for Shroud Tidal Current Power Generation System (쉬라우드 조류발전장치의 축소모형실험을 통한 발전 성능 분석)

  • Han, Seok Jong;Lee, Uk Jae;Park, Da In;Lee, Sang Ho;Jeong, Shin Tark;Lee, Sang Seol
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.31 no.4
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    • pp.221-228
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    • 2019
  • Experimental investigation was performed to analyze the flow field characteristics and power generation performance for a shroud tidal power generation system. Electrical power output was compared with the rotational speed of the turbine blade and electric load connected to the generator for various flow velocity. As the electrical load decreased, the speed of the turbine increased rapidly and reached by about 2 times. The power output also increased remarkably with the decrease of load, and then decreased after maximum power point. In addition, the maximum power point appeared at high electrical loads as the experimental flow velocity increased. These results of the flow field characteristics and power generation performance analysis of the shroud tidal power generation system variation with the flow velocity conditions and electrical load are expected to be the basic data necessary for the development of efficient shroud tidal power generation system.

Performance Assessment of Two Horizontal Shroud Tidal Current Energy Converter using Hydraulic Experiment (수리실험을 통한 수평 2열 쉬라우드 조류에너지 변환장치 성능평가)

  • Lee, Uk-Jae;Choi, Hyuk-Jin;Ko, Dong-Hui
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.34 no.1
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    • pp.1-10
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    • 2022
  • In this study, the two horizontal shroud tidal current energy converter, which can generate power even under low flow speed conditions, was developed. In order to determine the shape of the shroud system, a three-dimensional numerical simulation test was conducted, and a 1/6 scale down model was made to perform a hydraulic model experiment. The hydraulic model experiment was performed under four flow conditions, and the flow speed, torque, and RPM were measured for each experimental case. As a result of the numerical simulation test, it was found that the flow speeds passing through the nozzle were increased by about 2~3 times in the cylinder, and when the extension ratio was 2:1, the highest flow speed was shown. In addition, it was found that the flow speeds increased 2.8 times when the diameter ratio between the nozzle and the cylinder was 1.5:1. Meanwhile, as a result of the hydraulic model experiment, it was found that when the tip speed ratio was between 1.75 and 2, the power coefficient was 0.32 to 0.34.

Electrolytic Reduction of 1 kg-UO2 in Li2O-LiCl Molten Salt using Porous Anode Shroud (Li2O-LiCl 용융염에서의 다공성 양극 슈라우드를 이용한1kg 우라늄산화물의 전해환원)

  • Choi, Eun-Young;Lee, Jeong;Jeon, Min Ku;Lee, Sang-Kwon;Kim, Sung-Wook;Jeon, Sang-Chae;Lee, Ju Ho;Hur, Jin-Mok
    • Journal of the Korean Electrochemical Society
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    • v.18 no.3
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    • pp.121-129
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    • 2015
  • The platinum anode for the electrolytic reduction process is generally surrounded by a nonporous ceramic shroud with an open bottom to offer a path for $O_2$ gas produced on the anode surface and prevent the corrosion of the electrolytic reducer. However, the $O^{2-}$ ions generated from the cathode are transported only in a limited fashion through the open bottom of the anode shroud because the nonporous shroud hinders the transport of the $O^{2-}$ ions to the anode surface, which leads to a decrease in the current density and an increase in the operation time of the process. In the present study, we demonstrate the electrolytic reduction of 1 kg-uranium oxide ($UO_2$) using the porous shroud to investigate its long-term stability. The $UO_2$ with the size of 1~4mm and the density of $10.30{\sim}10.41g/cm^3$ was used for the cathode. The platinum and 5-layer STS mesh were used for the anode and its shroud, respectively. After the termination of the electrolytic reduction run in 1.5 wt.% $Li_2O-LiCl$ molten salt, it was revealed that the U metal was successfully converted from the $UO_2$ and the anode and its shroud were used without any significant damage.

The Actual Condition and Problems of Current Shrouds (현행수의의 실태 및 문제점)

  • 조효숙;안지원
    • Journal of the Korean Society of Costume
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    • v.52 no.3
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    • pp.123-137
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    • 2002
  • The purpose of this study is to analyze the actual condition and problems of current ready-made shrouds. Current shrouds were formed after the 20th century and therefore are quite apart from its traditional precedents of Chosun Dynasty. In this respect, several problems can be pointed out. 1. The use of natural colored hemp as a primary textile of current shrouds is far from our tradition. Silk, ramie, and cotton have to be used together with hemp. Also, more variety of colors can be used other than natural white. 2. The size of ready-made shrouds has to be categorized at least into three: large, medium and small 3. The pattern and sowing method of Dopo(도포) and Wonsam(원삼) should be corrected in line with those of the traditional Dopo(도포) and Wonsam(원삼). 4. The design and items of current ready-made shrouds have to break away from the standardized convention and should seek more of a variety that our rich tradition provide. 5. The rational index should be suggested so that consumers can compared the quality and price of ready-made shrouds available at their hands.

A Study of Choson Shrouds and Current Shrouds How the Deceased Are Clothed (조선시대 수의와 현행 수의의 착의법에 관한 연구)

  • 남민이;한명숙
    • The Research Journal of the Costume Culture
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    • v.8 no.6
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    • pp.822-841
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    • 2000
  • The purpose of this study is to organize how the deceased are clothed. Although there are many people who have seen the dead clothed once or twice and although the clothing has been constantly going on, there have been no books or studies on how the deceased are clothed. Instead, the methods have only been handed down orally by seniors and others who are experienced in it. I see the necessity of systematizing the method of clothing the deceased so that both ordinary people as well as experts can utilize it properly to show their sincerity and courtesy towards the dead. This study is based on literature including old books, dissertations, publications, and reports on ethnic customs. It also refers from interview results of shrouds makers, those experienced in clothing the dead, and seniors knowledgeable in the trade. Funeral manifested the social status of the dead. Shrouds of the olden days had different colors, such as white, black, blue, red, etc. according to items. However, nowadays they are white, pink, or partially light blue or sometimes people just keep the colors of their original cloths. Current items do not differ much from those of the ancient times, though Kwadu, Km, and Po, which were used to cover the belly, have been relatively simplified. The form of shrouds has changed nowadays. There are differences in the funeral procedures and how the deceased are clothed. In the olden days, when a person died, the body was cleaned up and clothed the very next after death. Nowadays, the cleansing and clothing of the body and placing the body in the coffin are all done together the following day. According to the foregoing, though there are no big differences in the way the deceased are clothed between the olden days and the present, the order in which Aksu and B누 are placed, differs and the procedures, items and shape have been simplified.

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Effect of Cl2 on Electrodeposition Behavior in Electrowinning Process

  • Kim, Si Hyung;Kim, Taek-Jin;Kim, Gha-Young;Shim, Jun-Bo;Paek, Seungwoo;Lee, Sung-Jai
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2017.10a
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    • pp.73-73
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    • 2017
  • Pyroprocessing at KAERI (Korea Atomic Energy Research Institute) consists of pretreatment, electroreduction, electrorefining and electrowinning. SFR (Sodium Fast Reactor) fuel is prepared from the electrowinning process which is composed of LCC (Liquid Cadmium Process) and Cd distillation et al. LCC is an electrochemical process to obtain actinides from spent fuel. In order to recover actinides inert anodes such as carbon material are used, where chlorine gas ($Cl_2$) evolves on the surface of the carbon material. And, stainless steel (SUS) crucible should be installed in large-scale electrowinning system. Therefore, the effect of chlorine on the SUS material needs to be studied. LiCl-KCl-$UCl_3$-$NdCl_3$-$CeCl_3$-$LaCl_3$-$YCl_3$ salt was contained in 2 kinds of electrolytic crucible having an inner diameter of 5cm, made of an insulated alumina and an SUS, respectively. And, three kinds of electrodes such as cathode, anode, reference were used for the electrochemical experiments. Both solid tungsten (W) and LCC were used as cathodes. Cd of 45 g as the cathode material was contained in alumina crucibles for the deposition experiments, where the crucible has an inner diameter of 3 cm. Glassy carbon rod with the diameter of 0.3 cm was employed as an anode, where shroud was not used for the anode. A pyrex tube containing LiCl-KCl-1mol% AgCl and silver (Ag) wire having a diameter of 0.1cm was used as a reference electrode. Electrodeposition experiments were conducted at $500^{\circ}C$ at the current densities of $50{\sim}100mA/cm^2$. In conclusion, Fe ions were produced in the salt during the electrodeposition by the reaction of chlorine evolved from the anode and Fe of the SUS crucible and thereby LCC system using SUS crucible showed very low current efficiencies compared with the system using the insulated alumina crucible. Anode shroud needs to be installed around the glassy carbon not to influence surrounding SUS material.

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A Study of Myokmok (멱목에 관(關)한 연구(硏究))

  • Yoo, Kwan-Soon
    • Korean Journal of Human Ecology
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    • v.9 no.4
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    • pp.459-469
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    • 2000
  • The purpose of this study is to investigate the Myokmok, a kind of shroud. This study classifies Myokmok by its size, shape, cloths and color. Korean Myokmok through literatures are as follows. The size of Myokmok was one Ch'ok(尺) two Ch'on(寸). The surface of Myokmok were mostly black and the lining was mostly red. The cloths of Myokmok were Paek(帛) and Chu(紬). Myokmok through relics was various in size and the cloths were Kongdan(貢緞), Myongchu(明紬) and the color was various. Actual conditions of current Myokmok were various. The size, shape and cloths were more variable than the literatures and relics. In the Chinese Myokmok through literatures, the size were one Ch'ok two Ch'on, one Ch'ok and one Ch'ok five Ch'on. The cloths of Myokmok were Paek and Kyon(絹). The surface of Myokmok were mostly black and the lining was mostly red. Myokmok in Munkonggaryoieuichul was tide by the strings of four corners. The size of the Chinese Myokmok was various. The shape of the current Myokmok was various than the literatures and relics.

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Numerical Study on the Effect of Cavity Vanes to Control the Axial Thrust of a Turbopump (터보펌프 축추력 조절용 캐비티 베인에 대한 수치해석적 연구)

  • Choi, Chang-Ho;Kim, Jin-Han;Noh, Jun-Gu
    • The KSFM Journal of Fluid Machinery
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    • v.9 no.2 s.35
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    • pp.39-43
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    • 2006
  • The magnitude of the axial force acting on turbopump bearings has a great influence on the operational reliability and service life of a turbopump. In the turbopump under current investigation the cavity vanes are introduced to the pump shroud casing to control the axial thrust of the turbopump. To investigate the effect of the cavity vanes, 3D computational flow analyses for a propellant pump stage including an inducer, impeller, volute and secondary flow passages are performed with and without the vanes. The results show that the cavity vanes are very effective in reducing the magnitude of axial thrust without notable changes on the overall performance of the turbopump.