• Title, Summary, Keyword: Surface Tension

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Effect of Single or Fractionated X-Irradiation on the Pulmonary Surfactant in Rabbits (단회(單回) 및 분획(分劃) X선(線) 흉부(胸部) 조사(照射)가 가토(家兎) 폐포(肺胞) 표면활성(表面活性) 물질(物質)에 미치는 영향(影響))

  • Kim, Jun;Choo, Young-Eun
    • The Korean journal of physiology & pharmacology
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    • v.4 no.2
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    • pp.53-60
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    • 1970
  • In an attempt to clarity the effect of X-irradiation on the activity of surfactant in rabbits, and also to observe the possible difference when the irradiation was made in single or fractionated dose, X-ray in dose of 900 r was irradiated to rabbits either in single or fractionated dose of 300 r each day for three day, Tension-area diagram of lung extract was recorded automatically by a modified Langmuir-Wilhelmy balance with a synchronized recording system designed in this department. The surface tension of lung extract was measured at 1,3,5,24, and 48 hours post-irradiation, and the results were compared with the non-irradiated normal group. The result obtained are summerized as follows: 1) The maximal surface tension, minimal surface tension, width of the tension-area diagram at the surface area of 40% in lung extract, and stability index of the normal rabbit lung extracts were 40.73 dynes/cm, 8.96 dynes/cm. 20.71 dynes/cm, and 1.28 respectively. 2) Activity of surfactant was significantly depressed by X-irradiation, and the pattern of depression was more prominent in the single irradiation group than in the fractionated group. 3) It was found that the changes of the width of the tension-area diagram at the surface area of 40% in lung extract and stability indices corresponded well with that of the maximal or minimal surface tension.

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A Study on Surface Tension Measurement for the Water through Electro-Magnetic Field (전자장을 통과한 물의 표면장력 측정에 대한 연구)

  • 고영하
    • Journal of the Korean Society of Marine Engineering
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    • v.27 no.7
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    • pp.826-831
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    • 2003
  • The purpose of this study was to measure the surface tension of hard water through electro-magnetic field for investigating the effect of electro-magnetic water treatment. The maximum reduction of surface tension was 8% comparing to the no treatment case. When the flow velocity through the permanent magnetic device (PMD) was 6.3 m/s, sample of hard water had the minimum surface tension.

A Study on the Flow with Interfacial Phenomena Using VOF Method

  • Baek, J.H.
    • 한국전산유체공학회:학술대회논문집
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    • pp.9-10
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    • 2006
  • A numerical method for simulating tree surface flows including the surface tension is presented. Numerical scheme is based an a fractional-step method with a finite volume formulation and the interface between liquid and gas is tracked by Volume of Fluid (VOF) method. Piecewise Linear Interface Calculation (PLIC) method is used to reconstruct the interface and the surface tension is considered using a Continuum Surface Force (CSF) model. Several free surface flow phenomena were simulated to show its effectiveness to find such phenomena.

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Influence of Surface Tension on Pinhole Phenomenon of Earthen Ware Glazes (도기유의 표면장력이 Pinhole 현상에 미치는 영향)

  • 지응업;이경재
    • Journal of the Korean Ceramic Society
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    • v.13 no.3
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    • pp.3-12
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    • 1976
  • The corelation between surface tensions and surface appearances of SK O5a opaque glazes for earthen wares were investigated. The surface tension values were theoretically calculated by using Dietzel's factors of constituent oxides of glaze. The surface appearances of glazes, especially the pinhole phenomena were strongly effected by the surface tension values showing the following general tendencies: (1) In the range of 305±3 dynes/cm of surface tensions, glazes showed almost no pjnholes. (2) In the range of surface tensions less than 300 dynes/cm, the large numbers of small pinholes or eggshell textures were observed. (3) In the range of surface tensions higher than 310 dynes/cm, large and deep pinholes were observed. (4) The contact angles of glazes on the wall tile body substrate are in the good proportional agreement with the surface tension values calculated by Dietzel's factors.

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Engineering Elastic-Plastic Fracture Analysis for Semi-Elliptical Surface Cracked Plates Under Combined Bending and Tension (복합하중을 받는 평판에 존재하는 반타원 표면균열의 공학적 탄소성 파괴해석법)

  • Shim, Do-Jun;Kim, Yun-Jae;Choi, Jae-Boong;Kim, Young-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.6
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    • pp.1127-1134
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    • 2002
  • The present paper provides an engineering J estimation equation for surface cracked plates under combined bending and tension. The proposed equation is based on the reference stress approach, and the most relevant normalising loads to define the reference stress for accurate J estimations are given for surface cracked plates under combined bending and tension. Comparisons with J results from extensive 3-D FE analyses, covering a wide range of crack geometry, plate geometry and loading combination, show overall good agreement not only at the deepest point but also at arbitrary points along the crack front. for pure tension, agreement between the estimated J and the FE results is excellent, even at the surface point. On the other hand, for pure bending and combined bending and tension, the estimated J values become less accurate for locations close to the surface point. Thus the results in this paper will be useful to assess short-term fracture or low cycle fatigue of surface defects in plates under combined bending and tension.

Effect of REM Addition on The Surface Tension and The Critical Temperature of The Immiscible Liquid Phase Separation of The 60%Bi-24%Cu-16%Sn alloy

  • Park, Joong-Chul;Min, Soon-Ki;Lee, Joon-Ho
    • Korean Journal of Materials Research
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    • v.19 no.2
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    • pp.111-114
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    • 2009
  • For the fabrication of core-shell structure bimetallic lead-free solder balls, both the critical temperature ($T_{cr}$) for the phase separation of two immiscible liquid phases and the temperature coefficient of the interfacial tension between the two separated liquid phases are required. In order to obtain this information, the temperature dependence of the surface tension of 60%Bi-24%Cu-16%Sn(-REM) alloys was measured using the constrained drop method. The slope of the temperature dependence of the surface tension changed clearly at a critical temperature for the separation of two immiscible liquid phases. The critical temperature of the 60%Bi-24%Cu-16%Sn alloy was estimated to be 1097K. An addition of 0.05% Ce decreased the critical temperature to 1085K, whereas that of 0.05% La increased it to 1117K. It was found that the surface tension and its temperature coefficient of the 60%Bi-24%Cu-16%Sn alloy were slightly increased by the addition of 0.05% Ce and 0.05% La. In addition, additions of Ce and La increased the temperature coefficient of the interfacial tension.

The Elongation Method for the Measuring Surface Tension of High Viscosity Printing Ink (II) (인장법에 의한 고점도 잉크의 표면장력 측정법 (II))

  • Ha, Young-Baeck;Youn, Jong-Tae;Koo, Chul-Whoi
    • Journal of the Korean Printing Society
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    • v.22 no.2
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    • pp.23-36
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    • 2004
  • The surface tension method has been possible only for the low viscosity materials. However, the inks for the off-set lithography and intaglio should have high viscosity and high tack. In this paper, we propose the elongation method to estimate the surface tension of high viscosity printing inks. The elongation method could be more useful to estimate the surface tension and shown in this research, it is possible to calculate the surface tension of high viscoxity ink without diluting the sample.

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Surface Properties and Betergency of the Binary Surfactant Mixture (계면활성제 혼합용액의 계면특성 및 세척성에 관한 연구)

  • 심소희;박정희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.21 no.3
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    • pp.632-640
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    • 1997
  • Changes in surface properties and detergency of sunactant mixtures were investigated in order to study the optimum mixing ratio of anionic and nonionic surfactants by measuring surface tension, interfacial tension, suspendability, and emulsification as a Amction of mixing ratio. Also, surface tension and detergency of the surfactant mixtures were determined with the increase of water-hardness or temperature. The results were as follows: the addition of NPE to anionic surfactant solutions (LAS or SDS) by 0.1 mole fraction remarkably decreased surface tension. NPE (n=15)/anionic surfactant mixtures showed a synergistic effect in lowering interfacial tension and emulsification, but NPE (n=7.5)/anionic surfactant mixtures did not. In suspension stability, however, synergism appeared when LAS or 505 was mixed with both of NPE's. With respect to the hydrophile of NPE, NPE (n=15) was more effective than NPE (n=i.5) in improving suspension stability. Detergency of LAS/NPE mixture changed almost linearly with mixing ratio, but that of SDS/NPE mixture increased remarkably by the addition of 0.1 or 0.2 mole fraction of NPE at all temperatures. As the temperature increased, surface tension of surfactant mixtures decreased and detergency was improved, but their synergistic effect decreased. In hard water, the mixtures showed better detergency than single surfactuant solutions.

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Experimental Study on the Droplet Formation in a Microchannel with a Cross Junction (십자형 마이크로 채널 내에서의 액적 형성에 관한 실험적 연구)

  • Park, Jae-Hyoun;Bae, Ki-Hwa;Heo, Young-Gun;Suh, Yong-Kweon
    • Journal of the Korean Society of Visualization
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    • v.5 no.2
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    • pp.39-47
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    • 2007
  • This paper describes an experimental study on the droplet formation and the subsequent motion in a microchannel having a cross junction. While one kind of liquid (pure water or water-surfactant mixture) is drawn into a horizontal inlet channel, the other kind (oil) is introduced through two vertical inlet channels. Due to the effect of surface tension on the interface between the two fluids, the droplets of the first fluid are formed near the cross junction. In this study, we have found that the droplet formation is affected even by slight difference in the surface tension. When the surface tension between two fluids is decreased, the droplet size is decreased in order to keep the equilibration between the pressure and the surface tension. In addition, the time interval between each of the droplet formations is decreased and the distance between droplets is also decreased when the surface tension is decreased.

Review of Membrane Tension Maintenance System for Membrane Structures through Membrane Tension Measurement (막장력 측정을 통한 막구조물의 장력 유지관리 시스템 검토)

  • Jin, Sang-Wook;Shon, Su-Deok;Lee, Seung-Jae
    • Journal of the Korean Association for Spatial Structures
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    • v.16 no.2
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    • pp.39-45
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    • 2016
  • Membrane structure is a system that is stabilized by maintaining a tensile state of the membrane material that originally cannot resist the bending or pressure. Also, it is a system that allows the whole membrane structure to bear external loads caused by wind or precipitation such as snow, rain and etc. Tension relaxation phenomenon can transpire to the tension that is introduced to the fabric over time, due to the innate characteristics of the membrane material. Thus, it is important to accurately understand the size of the membrane tension after the completion of the structures, for maintenance and management purposes. The authors have proposed the principle of theoretically and indirectly measuring the tension by vibrating the membrane surface with sound waves exposures against the surface, which is compartmentalized by a rectangular boundary, and by measuring the natural frequency of the membrane surface that selectively resonates. The authors of this paper measured the tension of preexisting membrane structure for its maintenance by using the developed portable measurement equipment. Through analyzing the measurement data, the authors review the points that should be improved and the technical method for the new maintenance system of membrane tension.