• 제목/요약/키워드: Korean Liquid

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Development of cryogenic liquid-vapor separator and liquid-level meter operating under high pressure condition (고압 상황에서 작동되는 극저온 기액 분리기와 액체 계면 측정기의 개발)

  • Lee, Cheon-Kyu;Hwang, Gyu-Wan;Jeong, Sang-Kwon
    • Progress in Superconductivity and Cryogenics
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    • v.13 no.1
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    • pp.51-55
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    • 2011
  • In this study, the liquid-vapor (L-V) separator equipped with liquid-level meter is developed. In the developed L-V separator, the flange is designed to be attachable so that the separator can be flexibly applied under any cases where the volumetric of L-V separator is varied by the system requirement. The leak-tightness between the attachable flange and the chamber is experimentally confirmed with the use of double groove indium wire sealing even under the high pressure up to 20 bar. In addition, the liquid-level meter is designed and fabricated to figure out the inner state of L-V separator. It consists with 19 carbon composition resistors in series. All resistors are separately calibrated in the temperature range from 77 K to 200 K. The performance of the L-V separator and the liquid-level meter is investigated with experimental tests, and the result is presented in this paper.

Development of Handles for Liquid Container through the Evaluation of User Preferences (사용자 선호도 평가를 통한 액체 저장용기의 손잡이 개발)

  • Jung, Hwa-Shik;Jung, Hyung-Shik
    • IE interfaces
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    • v.16 no.4
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    • pp.515-525
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    • 2003
  • In this study, a prototype liquid container combined with auxiliary handles was designed to increase the safety of manual handling and protect from contamination of hands of people who use these containers. Likert summated rating method as well as pairwise ranking test was applied to evaluate the user preferences for provided handles of the container under the conditions of different shapes and positions. The results show that the subjects preferred perpendicular orientation of the handle on the top of the liquid container while carrying the containers and the crosswise position of the handle at the side of the container while pouring the liquid were preferred. A prototype liquid container with provided auxiliary handles was developed based on the results of evaluation. It is thus recommended that the liquid container provide extra handles to reduce the musculoskeletal stress and in turn to increase the user satisfaction.

The History of Liquid Ear Acupuncture and the Current Scientific State of the Art

  • Litscher, Daniela;Litscher, Gerhard
    • Journal of Pharmacopuncture
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    • v.19 no.2
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    • pp.109-113
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    • 2016
  • This short review article presents a current overview of existing publications and scientific results regarding liquid (ear) acupuncture. The injection of liquids into defined acupuncture points of the ear is not a method commonly used in the Western world. The term liquid acupuncture has different definitions, which makes understanding each definition and differentiating one from the other difficult. General terms like pharmacopuncture, homeosiniatry, and liquid acupuncture, which all describe the method of injecting different kinds of drugs into a defined body acupuncture point, are used. This article presents the history of liquid acupuncture, as well as the current scientific state of the art, from the point of view of two European researchers. Some articles are discussed and a few practical examples are presented.

Laminar Film Condensation Model of Pure Steam in a Vertical Tube (수직관 내 순수 증기의 층류 액막 응축 모델)

  • Kim, Dong Eok
    • The KSFM Journal of Fluid Machinery
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    • v.17 no.3
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    • pp.33-40
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    • 2014
  • In this study, a new model for calculating the liquid film thickness and condensation heat transfer coefficient in a vertical condenser tube is proposed by considering the effects of gravity, liquid viscosity, and vapor flow in the core region of the flow. In order to introduce the radial velocity profile in the liquid film, the liquid film flow was regarded to be in Couette flow dragged by the interfacial velocity at the liquid-vapor interface. For the calculation of the interfacial velocity, an empirical power-law velocity profile had been introduced. The resulting liquid film thickness and heat transfer coefficient obtained from the proposed model were compared with the experimental data from other experimental study and the results obtained from the other condensation models. In conclusion, the proposed model physically explained the liquid film thinning effect by the vapor shear flow and predicted the condensation heat transfer coefficient from experiments reasonably well.

Effect of droplet size on electro-optical switching properties of polymer dispersed liquid crystals (폴리머 분산 액정의 전기 광학적 스위칭 특성에 대한 액정방울 크기의 효과)

  • Kim, In-Tae;Yu, Yeon-Serk
    • Korean Journal of Optics and Photonics
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    • v.17 no.1
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    • pp.23-30
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    • 2006
  • Effects of liquid-crystal droplets size on electro-optical properties of the polymer dispersed liquid crystals are investigated experimentally The liquid crystal droplets size was varied by controlling the Laser power for phase separation and LC/oligomer composition ratio. Electro-optical switching voltage is dependent on the LC/oligomer composition ratio and liquid crystal droplet size. The experimental results showed droplet size will be small and saturation voltage is increased but rise time will be short at high power illumination laser light for phase separation.

Behavior of cryogenic gases in a closed space (밀폐된 공간에서 초저온 액화가스의 거동)

  • 이현철;강형석;박두선;손무룡
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2000.02a
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    • pp.48-51
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    • 2000
  • The behavior of cryogenic liquid stored in a closed cryogenic tank has been studied at various liquid levels, as a function of pressure and temperature on time, assuming heat leak(NER) is 0.7%/day. The pressure depends, as expected, on the liquid-vapor ratio in a tank. The calculation shows that if liquid level is as high as 90%,much higher than the critical volume ration, in a closed tank of designed pressure 11 bar, it takes 5.4 to 15days for the entire volume of the tank to be filled with liquid and 11 to 22 days for the tank to be exploded. If a closed tank is full of liquid, it is extremely dangerous because of abrupt pressure increase so that the safety devices are necessary to vent out pressurized gas. These phenomena can be explained with the liquid heat capacity, latent heat and compressibility.

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Design of Optimal Attitude Controller for a Launch Vehicle Using Sloshing Filter (슬로싱 필터를 이용한 발사체의 최적 자세제어기 설계)

  • Kim, Dong-Hyun;Choi, Jae-Weon
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.584-589
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    • 2000
  • When the liquid tanks only partially filled and under translational acceleration, large quantities of liquid move uncontrollably inside the tanks and generate the liquid sloshing effect. Liquid sloshing effect could be a severe problem in launch vehicle stability and control if the liquid modes of motion couple significantly with the launch vehicle's normal modes of motion. Several methods have been employed to reduce the effect of sloshing, such as introducing baffles inside the tanks or dividing a large tank into a number of smaller ones. These techniques, although helpful in some cases, do not succeed in canceling the sloshing effects. In this paper, An attitude controller is designed for a launch vehicle with liquid sloshing effect. Both PD controller and sloshing filter are designed for the objective. PD gains and design parameters are determined by optimal algorithm. The performance of the attitude controller is evaluated via computer simulations.

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Modeling an e-Beam Addressed Liquid Crystal Projection Display

  • Yang, Deng-Ke;Zhou, Fushan;Molitor, R.J.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.930-932
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    • 2002
  • We have carried a theoretical study on e-beam addressed liquid crystal projection display in which the liquid crystal is switched by the electric field of the charge, produced by an electron beam, on the surface of the display. We calculated the electric field produced by the surface charge, the liquid crystal director configuration and the profile of the transmitted light. We studied the factors affecting the resolution of the display. We also studied the effect of pretilt angle on the performance of the display. The e-beam addressed liquid crystal projection display potentially has the advantages of high resolution and high brightness.

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Development of Liquid Stub and Phase Shifter

  • Wang, Son-Jong;Yoon, Jae-Sung;Hong, Bong-Guen
    • Nuclear Engineering and Technology
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    • v.33 no.2
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    • pp.201-208
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    • 2001
  • The high power RF transmission line components are required for transmitting MW level RF power continuously in RF heating and current drive system which heat the plasma and produce plasma current in fusion reactor The liquid stub and phase shifter is proposed as the superior to the conventional stub and phase shifter. Experimental results show that they are reliable and easy to operate compared to the conventional stub and phase shifter. There is no distortion of reflected power during the raising of the liquid level. RF breakdown voltage is over 40kV. Temperature increment of the liquid is expected not to be severe. These results verify that the liquid stub and phase shifter can be used reliably in the high power continuous RF facilities.

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Estimation of Liquid Physical Properties of Mar-M247LC Superalloy by Directional Solidification (일방향 응고법을 이용한 Mar M-247LC 초내열합금의 액상 물성 측정)

  • Kim, Hyeon-Cheol;Lee, Jae-Hyeon;Seo, Seong-Mun;Kim, Du-Hyeon;Jo, Chang-Yong
    • Korean Journal of Materials Research
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    • v.11 no.9
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    • pp.721-726
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    • 2001
  • Directional solidification experiments have been carried out at the solidification rates from 0.5 to 50$\mu\textrm{m}$/s in Mar M-247LC superalloy in which several important liquid properties were estimated by analyzing the interface stability and temperature gradient at the solid/liquid interface. The diffusion coefficient in the liquid was estimated by employing the constitutional supercooling criterion. The temperature gradients changed with solidification rates and latent heat of solidification. The thermal conductivities of solid and liquid could be estimated by heat flux balance at the solid liquid interface.

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