• Title/Summary/Keyword: Liquid-solid

Search Result 2,333, Processing Time 0.026 seconds

Characteristics of Surface Flashover on Partially Immersed of Spacer in Liquid Nitrogen (액체질소 중에서 spacer의 부분적 침적에 대한 연면 방전특성)

  • 김영석;이병성;백승명;정종만;정순용;김상현
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.13 no.2
    • /
    • pp.177-182
    • /
    • 2000
  • Composite insulation system of liquid nitrogen and solid spacer is widely applied in high temperature superconduction power machine. This study has three step procedure. As follow, first step is composition of parallel deposited electrode and vertically deposited electrode along the direction of immersion in liquid nitrogen(LN2). Second step is investigation into surface flashover voltage of solid spacer under partially immersed in LN2, and last step is comparison the result of this research with that of fully immersed in LN2 and at cryogenic temperature gaseous nitrogen(GN2). This result presented that surface flashover voltage along solid spacer half immersed in LN2 was almost the same as that of fully immersed spacer when the thickness of spacer(t) was t<10mm. In the case of t> 10mm, however, spacer flashover voltage was equal to that obtained in GN2 at cryogenic temperature. And the immersed direction functions as role of deciding the difference of surface flashover voltage.

  • PDF

Design and Development of Fluidized Bed Cleaning System for on Heat Treatment Parts (I) - Design and Development the Experimental Fluidized Bed Cleaner and Experiments on its Cleaning Efficiency - (유동층을 이용한 열처리부품의 세정 시스템 설계 및 개발 (I) -유동층 이용 세정 실험장치 설계, 개발 및 실험 -)

  • Kim C.S.;Kim K.D.
    • Journal of Biosystems Engineering
    • /
    • v.31 no.4 s.117
    • /
    • pp.376-384
    • /
    • 2006
  • This study was conducted to perform for comparative analysis of the cleaning efficiency on 3 kinds of cleaning liquid state, 3 steps of cleaning temperature $(45^{\circ}C,\;60^{\circ}C,\;70^{\circ}C,\;)$ and 6 steps of cleaning time (2.5, 5, 7.5, 10, 12.5, 15 minute). 3 kinds of cleaning liquid state are the non fluidized bed, liquid fluidized bed and liquid/solid fluidized bed. UV spectrophotometer was used in estimation of cleaning efficiency, which it is experimental equipment using the absorptiometric analysis method. Cleaning efficiency by cleaning time was increase from 2.5 minutes to 15 minutes, liquid/siolid fluidized bed was indicated the highest cleaning efficiency among the 3 kinds of cleaning liquid state and $70^{\circ}C$ of cleaning temperature at liquid/solid fluidized bed was indicated the highest cleaning efficiency as 98% among the 3 steps of cleaning temperature.

An analytical solution for the close-contact melting with vertical convection and solid-liquid density difference (종방향대류 및 고액밀도차가 고려된 접촉융해에 대한 해석해)

  • Yu, Ho-Seon;Hong, Hui-Gi;Kim, Chan-Jung
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.21 no.9
    • /
    • pp.1165-1173
    • /
    • 1997
  • The steady state close-contact melting phenomenon occurring between a phase change material and an isothermally heated flat plate with relative motion is investigated analytically, in which the effects of vertical convection in the liquid film and solid-liquid density difference are incorporated simultaneously. Not only the scale analysis is conducted to estimate a priori qualitative dependence of system variables on characteristic parameters, but also an analytical solution to a set of simplified model equations is obtained to specify the effects under consideration. These two results are consistent with each other, in that the vertical convection affects both the solid descending velocity and the film thickness, and that the density difference alters only the solid descending velocity. While the effect of vertical convection can be characterized conveniently by a newly introduced temperature gradient factor which asymptotically approaches the unity/zero with decreasing/increasing the Stefan number, that of density difference is represented by the liquid-to-solid density ratio. It is shown that the solid descending velocity depends linearly on the density ratio, and that the ratios of solid descending velocity, film thickness and friction coefficient to the conduction solution are proportional to 3/4, 1/4 and -1/4 powers of the temperature gradient factor, respectively. Also, established is the fact that the effect of convection can be legitimately neglected in the analysis for the range of the Stefan number less than 0.1.

Changes in Sodium Content by Type of Jangajji and Length of Storage Period-By Applying an Analysis Technique to Differentiate Solid Ingredients from Seasoning Liquid- (장아찌의 종류와 저장기간에 따른 나트륨 함량 변화 - 건더기와 양념(국물)의 구분 분석법을 적용하여 -)

  • Jiyu Choi;So-young Kim
    • The Korean Journal of Food And Nutrition
    • /
    • v.37 no.2
    • /
    • pp.88-99
    • /
    • 2024
  • This study aimed to provide an accurate estimate of sodium intake from jangajji by examining the changes in sodium content according to the type of jangajji and the length of storage period, specifically differentiating between the solid ingredients and the seasoning liquid. It focused on six types of jangajji: chili pepper, perilla leaf, onion, radish, garlic scape, and cucumber. The sodium content in the solid ingredients and the seasoning was measured using a salinometer and ICP-AES. The results indicated that across all types of jangajji, the seasoning liquid consistently contained significantly higher levels of sodium than the solid ingredients. When comparing the sodium content measured by ICP-AES with that from a salinometer, the salinometer readings were significantly lower for both the solid ingredients and the seasoning liquid in all types of jangajji. Additionally, when comparing the sodium content of the solid ingredients with that listed in the nation's representative nutritional databases, a substantial discrepancy was noted, with some cases potentially overstating the actual sodium intake from jangajji. Overall, this study suggests that an urgent review should be conducted to identify and resolve the causes of such discrepancies and accurately estimate the actual sodium intake from jangajji.

NUMERICAL ANALYSIS OF THE SHOCK WAVES IN COMPRESSIBLE SOLIDS AND LIQUIDS USING A SIX-EQUATION DIFFUSE INTERFACE MODEL (6-방정식 확산경계 모델을 이용한 압축성 고체 및 액체에서 충격파 해석)

  • Yeom, Geum-Su
    • Journal of computational fluids engineering
    • /
    • v.17 no.3
    • /
    • pp.99-107
    • /
    • 2012
  • In this paper, the shock waves in compressible solids and liquids are simulated using a six-equation diffuse interface multiphase flow model that is extended to the Cochran and Chan equation of state. A pressure relaxation method based on a volume fraction function and a pressure-correction equation are newly implemented to the six-equation model. The developed code has been validated by a shock tube problem with liquid nitromethane and an impact problem of a copper plate on a solid explosive. In addition, a new problem, an impact of a copper plate on liquid nitromethane, has been solved. The present code well shows the wave structures in compressible solids and liquids without any numerical oscillations and overshoots. After the impact of a solid copper plate on liquid, two shock waves (one propagates into liquid and the other into solid) are generated and a material interface moves to the impacting direction. The computational results show that the shock velocity inside the liquid linearly increases with the impact velocity.

Effectiveness of a Solid Sialogogue to Stimulate Salivation in MR Sialography (자기공명 타액선조영검사 시 고체 타액분비 촉진제의 유용성)

  • Choi, Kwanwoo;Lee, Hobeom;Na, Sara;Son, Soonyong;Yoo, Beonggyu
    • Journal of the Korean Society of Radiology
    • /
    • v.10 no.8
    • /
    • pp.577-582
    • /
    • 2016
  • This study is aimed to prove that a solid sialogogue can improve the defects of the liquid one and substitute it with no differences in the signal intensity. From January to August 2016, 60 patients with no salivary gland diseases were enrolled. The patients were divided into two groups as follows; a group with a liquid sialogogue and the other group with a solid sialogogue. MR images were acquired and signal intensities of the parotid glands were compared. As a result, the signal intensities of liquid and solid sialogogues showed no statistically significant differences($59.42{\pm}15.74$ and $61.80{\pm}13.99$, respectively) In conclusion, a solid sialogogue was verified to have no signal intensity differences from the liquid one while it could improve the defects of the liquid sialogogue.

Fabrication of TiO2 Nanowires Using Vapor-Liquid-Solid Process for the Osseointegration (골융합을 위한 Vapor-Liquid-Solid 법을 이용한 TiO2 나노와이어의 합성)

  • Yun, Young-Sik;Kang, Eun-Hye;Yun, In-Sik;Kim, Yong-Oock;Yeo, Jong-Souk
    • Journal of the Korean Vacuum Society
    • /
    • v.22 no.4
    • /
    • pp.204-210
    • /
    • 2013
  • In order to improve osseointegration for biomedical implants, it is crucial to understand the interactions between nanostructured surfaces and cells. In this study, $TiO_2$ nanowires were prepared via Vapor-Liquid-Solid (VLS) process with Sn as a metal catalyst in the tube furnace. Nanowires were grown with $N_2$ heat treatment with their size controlled by the agglomeration of Sn layers in various thicknesses. MC3T3-E1 (pre-osteoblast) were cultured on the $TiO_2$ nanowires for a week. Preliminary results of the cell culture showed that the cells adhere well on the $TiO_2$ nanowires.

Yield and Compression Behavior of Semi-Solid Material by Upper Bound Method (상계법에 의한 반융용 재료의 항복과 압축거동)

  • 최재찬;박형진;박준홍
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1995.10a
    • /
    • pp.195-198
    • /
    • 1995
  • In Semi-Solid Forging, it is necessary to control the forming variables accurately in order to make near-net-shape products. Generally, the defects of products may occur due to liquid segregation which can be caused by the degree of deformation and condition of friction in Semi-Solid Forging, where the segregation is to be predicted by flow analysis. This paper presents the feasibility of theoretical analysis model using the new yield function which is proposed by Doraivelu et al. to the flow analysis of the semi-solid dendritic Sn-15%Pb alloys instead of adopting the yield criterion of Shima & Oyane which is used by Charreyron and usefulness of the adopted yield function. The distribution of the liquid fraction at various strains in radial direction and the influence of friction are estimated by Upper Bound Method.

  • PDF

Disengagement of a Pendant Liquid Drop from a Vibrating Ceiling (진동하는 고체면에 매달린 액적의 분리 현상)

  • 김호영;강승민;강병하
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.13 no.4
    • /
    • pp.295-303
    • /
    • 2001
  • Condensation of vapor on solid inherently accompanies generation of liquid drops on the solid surface. However, these drops prevent the solid surface from directly contacting the saturated vapor, thus causing thermal resistance. This work investigates a novel mechanism for enhancing the condensation process, in which the condensed drops are rapidly removed from a solid surface by imposing vibration on them. In the experiments, a water drop pendant from a solid surface is vibrated at a fixed frequency while increasing the vibration amplitude. Upon repeating the experiments using various frequencies, it is revealed that there exist resonant frequencies at which the minimum vibration amplitudes inducing a fall-off of the pendant drops are remarkably less than those at neighboring frequencies. These frequencies are supposed to correspond to the resonant frequencies for different modes of drop shape oscillations. They are compared with the resonant frequencies predicted by relatively simple analyses, and the factors causing discrepancy between then are discussed.

  • PDF

The Effect of Gate Shape for Semi-Solid Forging Die on the Filling Limitation (반용융 단조금형의 Gate 형상이 성형성에 미치는 영향)

  • Son Y. I.;Kang C. G.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2000.10a
    • /
    • pp.178-184
    • /
    • 2000
  • To obtain high quality component with thixoforming process, it is important that the homegeneous distribution of solid particles without liquid segregation. In closed-die semi-solid forging process, liquid segregation is strongly affected by injection velocity than any other process variables because the material has to travel relatively long distance to fill the cavity through a narrow gate before solidification begins. The optimal injection velocity and die temperature were investigated to fabricate near-net-shape compressor component called Al frame.

  • PDF