• Title/Summary/Keyword: Liquid structure

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Measuring Nano-Width of Wave Fronts in Combustion: a Numerical Approach (연소시 발생하는 파면의 나노 사이즈 두께 측정: 수치적 접근)

  • Yoh, Jai-Ick
    • 한국연소학회:학술대회논문집
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    • 2005.10a
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    • pp.20-27
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    • 2005
  • I consider the structure of steady wave system which is admitted by the continuum equations for materials that undergo phase transformations with exothermic chemical reaction. In particular, the dynamic phase front structures between liquid and gas phases, and solid and liquid phases are computationally investigated. Based on the one-dimensional continuum shock structure analysis, the present approach can estimate the nano-width of waves that are present in combustion. For illustration purpose, n-heptane is used in the evaporation and condensation analysis and HMX is used in the melting and freezing analysis of energetic materials of interest. On-going effort includes extension of this idea to include broad range of liquid and solid fuels, such as rocket propellants.

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A Study on Vibration Characteristics with Sloshing Mode Effect in Water Tank Structure (유체 슬로싱모드가 탱크의 진동에 미치는 영향에 대한 연구)

  • Bae, Sung-Yong
    • Journal of the Society of Naval Architects of Korea
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    • v.40 no.6
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    • pp.88-95
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    • 2003
  • Liquid storage rectangular tank structures are used in many fields of airplane and marine engineering. Fatigue damages are sometimes observed in these tanks which seem to be caused by resonance. Therefore it is essentially important to estimate vibration characteristics of tank structures. Many Investigators studied the vibration of cylindrical and rectangular tank structures containing still fluid. In general, the eigenbehavior of interior liquid is characterized by the sloshing mode while that of the structure by the bulging mode. However, the structure deformation to the sloshing mode and the liquid free-surface fluctuation to the bulging mode have been neglected in the classical added-mass computation. in the present paper, we study the vibration characteristics with sloshing mode effect.

Fusion Mechanism of Liquid according to the Significant Liquid Structure Theory

  • Kim, Ui-Rak;Jhon, Mu-Shik
    • Nuclear Engineering and Technology
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    • v.3 no.1
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    • pp.33-36
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    • 1971
  • With the use of the significant structure theory of liquid, the fusion criteria has been successfully explained. To test the theory of fusion, the excess volume upon melting has been calculated for some liquids such as simple liquids and fused salts. The results obtained show good agreements between theory and experiment. The theoretical study on the fused salt may be useful to understand the properties and structure of high temperature liquids in the atomic reactor.

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Physical Properties and Dyeability of Cotton Fabrics Treated with Liquid Ammonia (액체암모니아 처리 면직물의 물성 및 염색성)

  • Jeon, Sung-Ki;Lee, Chang-Soo;Im, Yong-Jin;Lee, Chung;Kim, Tae-Kyung;Lee, Hye-Jung
    • Textile Coloration and Finishing
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    • v.15 no.4
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    • pp.73-79
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    • 2003
  • It is generally known that cotton treated with liquid ammonia has better soft handle, wrinkle recoveries and stability of appearance as compared with the alkali mercerized cotton. In this study, the various cotton fabrics treated with liquid ammonia$(NH_3)$, sodium hydroxide(NaOH) and sodium hydroxide(NaOH)/liquid ammonia$(NH_3)$ and untreated cotton fabric were investigated and compared in terms of physical properties and dyeing behavior. As the result, the strength of four kinds of cotton fabrics were similar. But the elongation of cotton treated with liquid ammonia increased slightly. Liquid ammonia treatment reduced the crystallinity of cotton and the crystalline structure of cotton transformed from cellulose 1 to mixed structure of celluloseIand III. In dyeing, dyeing rate decreased but equilibrium dye uptake increased by liquid ammonia treatment of cotton fabrics.

Experimental study on tuned liquid damper performance in reducing the seismic response of structures including soil-structure interaction effect

  • Lou, Menglin;Zong, Gang;Niu, Weixin;Chen, Genda;Cheng, Franklin Y.
    • Structural Engineering and Mechanics
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    • v.24 no.3
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    • pp.275-290
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    • 2006
  • In this paper, the performance of a tuned liquid damper (TLD) in suppressing the seismic response of buildings is investigated with shake table testing of a four-story steel frame model that rests on pile foundation. The model tests were performed in three phases with the steel frame structure alone, the soil and pile foundation system, and the soil-foundation-structure system, respectively. The test results from different phases were compared to study the effect of soil-structure interaction on the efficiency of a TLD in reducing the peak response of the structure. The influence of a TLD on the dynamic response of the pile foundation was investigated as well. Three types of earthquake excitations were considered with different frequency characteristics. Test results indicated that TLD can suppress the peak response of the structure up to 20% regardless of the presence of soils. TLD is also effective in reducing the dynamic responses of pile foundation.

Analysis of Fluid-Structure Interactions Considering Nonlinear Free Surface Condition for Base-isolated Fluid Storage Tank (면진된 유체저장탱크의 비선형 유체-구조물 상호작용 해석)

  • Kim, Moon-Kyum;Lim, Yun-Mook;Cho, Kyung-Hwan;Jung, Sung-Won;Eo, Jun
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.09a
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    • pp.481-488
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    • 2003
  • A fluid-structure-isolator interaction program was developed in this study. The behavior of liquid regions are simulated by the boundary element method, and then the technique of analyzing the free surface motion in time domain is developed by using the nonlinear free surface boundary condition(NFBC) and the condition of interface between the structure and the fluid. Structure regions are modeled by the finite element method. In order to construct the governing equation of the fluid structure interaction(FSI)problem in time domain, the finite elements for a structure and boundary elements for liquid are coupled using the equilibrium condition, the compatibility condition and NFBC. The isolator is simulated by equation proposedin 3D Basis Me. In order to verify the validity and the applicability of the developed fluid- structure -Isolator interaction program, The horizontal forced vibration analysis was performed. The applicability of the developed method is verified through the artificial seismic analysis of real size liquid storage tank.

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Transient State Theory of Significant Liquid Structure applied to Cyclohexane (액체구조에 관한 천이상태이론의 싸이클로 핵산에 대한 적용)

  • Lee, Hai-Bang;Chang, Sei-Hun
    • Journal of the Korean Chemical Society
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    • v.10 no.3
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    • pp.129-132
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    • 1966
  • It is known that almost all cyclohexane molecules are chair form in liquid state. Therefore, only chair form is considered in formulating the partition function for liquid cyclohexane, according to the Transient State Theory of Significant Liquid Structure proposed by Pak, Ahn and Chang. The thermodynamic quantities such as molar volume, vapor pressure, entropy of vaporization and compressibility of the liquid are calculated. The results are in good agreement with experimental values.

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Effect of Liquid Surface Treatments on Field Emission Properties of Carbon Nanotube Cathodes

  • Lee, Ji-Eon;An, Young-Je;Shin, Heon-Cheol;Chung, Won-Sub;Cho, Young-Rae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.486-489
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    • 2007
  • Carbon nanotube (CNT) cathodes having a trench structure similar to the structure of the gated triodetype cathode were successfully fabricated by a screenprinting method with multi-walled carbon nanotubes. We observed that a liquid method not only readily removes the organic residues on the CNT films, but also satisfactorily protrudes the CNTs out of the electrode surface. The CNT cathodes prepared by the liquid method showed a turned-on field of $1.4\;V/{\mu}m$. The emission current density of them was about $3.1\;mA/cm^2$ at the electric field of $3\; V/{\mu}m$. The liquid method appears to be a promising surface treatment of CNT cathode for gated triode-type FEDs applications.

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Vertical Alignment Nematic Liquid Crystal Display with Patterned Electrode Using Positive Liquid Crystal Materials

  • Shin, Hun-Ki;Yoon, Tae-Hoon;Kim, Jae-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.499-501
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    • 2007
  • We propose a vertical-alignment liquid crystal display with patterned electrodes using a positive dielectric anisotropic liquid crystal. In this structure, the threshold and on-state voltages are reduced compared with previous vertical-alignment configuration with positive liquid crystal.

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Characterization of the Oxide Layer Formed on the Cu-Zr Based Metallic Glass during Continuous Heating

  • Lim, Ka-Ram;Kim, Won-Tae;Kim, Do-Hyang
    • Applied Microscopy
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    • v.42 no.3
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    • pp.174-178
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    • 2012
  • In the present study, the oxidation behavior of $Cu_{50}Zr_{50}$ and $Cu_{46}Zr_{46}Al_8$ metallic glasses has been investigated using transmission electron microscopy with a particular attention on the oxidation behavior in the supercooled liquid state. Identification of the oxidation product after continuous heating treatment shows that in $Cu_{50}Zr_{50}$ metallic glass, $ZrO_2$ with the monoclinic structure forms on the supercooled liquid as well as on the crystallized matrix. On the contrary, in $Cu_{46}Zr_{46}Al_8$ metallic glass, $ZrO_2$ with the tetragonal structure forms on the supercooled liquid, but that with the monoclinic structure forms on the crystallized matrix. The result indicates that the $Cu_{50}Zr_{50}$ metallic glass exhibits far better oxidation resistance in the supercooled liquid state than the $Cu_{46}Zr_{46}Al_8$ metallic glass.