• Title/Summary/Keyword: thermal physical properties

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Effect of Heat Treatment on the Physical Properties of LM PET Jacquard Fabrics (저융점 폴리에스터 자카드직물의 물성에 대한 열처리 효과)

  • Lee, Sun Young;Kim, Jeong Hwa;Kim, Eui Hwa;Lee, Jung Soon;Lee, Seung Goo
    • Textile Coloration and Finishing
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    • v.25 no.3
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    • pp.206-214
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    • 2013
  • There has been an increasing demand for high performance and energy-saving of blind. In order to develop the eco-friendly blind textiles, heat treatment process has been utilized for LM(Low Melting) polyester fabrics and the changes of the physical properties of the treated fabrics were examined according to temperature of heat treatment. Morphology, surface reflectance, contact angle, luster, thermal property and mechanical property of heat treated LM polyester fabrics were investigated. As results, morphology analysis of thermal treated fabrics confirmed that degree of fusion of LM polyester yarns improved with increase of temperature. Surface reflectance of thermal treated fabrics decreased with increase of temperature. Luster and contact angle of a water droplet on thermal treated fabrics increased slightly with increase of temperature. The mechanical properties of the fabrics by KES-FB system were found to be temperature-dependent and especially, bending and shear properties among them were highly related to temperature.

Fabrication of the Cu-STS-Cu Clad Metal for High Strength Electric Device Lead Frame and Thermal Stability on Their Physical Properties (고강도 전자소자 리드프레임용 Cu/STS/Cu 클래드 메탈제조 및 물리적특성에 대한 열안정성 연구)

  • Kim, Il-Gwon;Son, Moon-Eui;Kim, Young-Sung
    • Journal of Welding and Joining
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    • v.32 no.5
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    • pp.80-86
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    • 2014
  • We have successfully fabricated high strengthening Cu/STS/Cu 3 layered clad metal of $70kgf/mm^2$ grade for electric device lead frame, and investigated thermal effect of the mechanical and physical properties on the Cu/STS/Cu 3 layered clad metal lead frame material at different temperatures ranging from RT to $200^{\circ}C$. The fabricated clad metal shows a good thermal stability under 6% degrading of mechanical tensile strength and hardness change at $200^{\circ}C$ and also physical properties show stable thermal and electrical conductance of over $220W/m{\cdot}K$ and 58.44% IACS upto the $200^{\circ}$. The results confirm that fabricated high strengthening Cu/STS/Cu 3 layered clad metal can be applied for the high performed electrical lead frame devices.

Nonlinear thermal displacements of laminated composite beams

  • Akbas, Seref D.
    • Coupled systems mechanics
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    • v.7 no.6
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    • pp.691-705
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    • 2018
  • In this paper, nonlinear displacements of laminated composite beams are investigated under non-uniform temperature rising with temperature dependent physical properties. Total Lagrangian approach is used in conjunction with the Timoshenko beam theory for nonlinear kinematic model. Material properties of the laminated composite beam are temperature dependent. In the solution of the nonlinear problem, incremental displacement-based finite element method is used with Newton-Raphson iteration method. The distinctive feature of this study is nonlinear thermal analysis of Timoshenko Laminated beams full geometric non-linearity and by using finite element method. In this study, the differences between temperature dependent and independent physical properties are investigated for laminated composite beams for nonlinear case. Effects of fiber orientation angles, the stacking sequence of laminates and temperature on the nonlinear displacements are examined and discussed in detail.

A Study on Thermo-Physical Properties of Microencapsulated Phase Change Material Slurry (마이크로캡슐 잠열 축열재 혼합수의 열물성에 관한 연구)

  • 임재근;최순열;김명준
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.6
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    • pp.962-971
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    • 2004
  • This paper has dealt with thermo-physical properties of microencapsulated phase change material slurry as a latent heat storage material having a low melting point. The measured results of the thermo-physical properties of the test microencapsulated phase change material slurry, those are, density, specific heat, thermal conductivity and viscosity, were discussed for the temperature region of solid and liquid phases of the dispersion material (paraffin). The measurements of these properties of microencapsulated phase change material slurry have been carried out by using a specific-gravity meter, a water calorimeter, a differential scanning calorimeter(DSC), a transient hot wire method and rotating type viscometer, respectively. It was clarified that the additional properties law could be applied to the estimation of the density and specific heat of microencapsulated phase change material slurry and also the Euckens equation could be applied to the estimation of the thermal conductivity of this slurry.

Analysis on the Physical Property of Nylon High Tenacity Coarse Yarn and Fabric for Military and Technical Textiles (군용 및 산자용 나일론 고강력 태섬사 및 후직물의 물성 분석)

  • Kim, Seung-Jin;Kim, Sang-Ryong;Lee, Do-Hyun;Choi, Woo-Hyuk
    • Textile Coloration and Finishing
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    • v.21 no.3
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    • pp.43-48
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    • 2009
  • This paper surveys the mechanical properties of nylon high tenacity coarse yarn and fabric for military and technical textiles. For this purpose, 6 kinds of yarns and 2 kinds of fabrics are prepared. The yarn physical properties such as yarn count, thermal shrinkages, and tensile properties are measured and discussed with the characteristics of the domestic and imported yarns. And, the physical and mechanical properties of these fabrics are also measured and discussed with the usage of these fabrics in the military and technical textiles fields. Hereafter, the differences of physical properties between domestic and foreign yarn specimens for high functional military and technical fabrics are estimated through this study.

PROPERTIES OF PLASMA SPRAYED COATINGS

  • Ding, C.X.;Zhang, Y.F.;Xia, J.Y.
    • Journal of the Korean Vacuum Society
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    • v.4 no.S2
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    • pp.58-63
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    • 1995
  • Plasma spray has attracted attention as an effective method for obtaining protective coatings. In this paper, the physical, mechanical and thermal properties of coatings are reviewed. The microstructural features of the coatings are described. The relationship between the properties of coatings and their microstructure is also discussed. Plasma sprayed coatings are used to reduce wear and improve thermal protection on a large number of components in various industries. In some cases, the conditions of application are very aggressive and therefore the resulting maintenance costs are expensive. Improved coating materials and appropriate properties of coatings are the most promising ways to solve these problems[1,2]. The optimum coating properties depend on the microstructure of coatings[1-5]. In this paper, some ceramic coatings frequently used in industries were reported. The physical, mechanical and thermal properties of ceramic coatings are reviewed. The microstructure features of coatings are addressed. The relationship between the microstructure of coatings and their properties are discussed.

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Phase Evolution and Thermo-physical Properties of Rare-earth Oxides for Thermal Barrier Systems (열차폐용 희토류 산화물의 상형성과 열물성)

  • Shim, Byung-Chul;Kwak, Kil-Ho;Lee, Sung-Min;Oh, Yoon-Suk;Kim, Hyung-Tae;Jang, Byung-Koog;Kim, Seong-Won
    • Journal of Powder Materials
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    • v.17 no.2
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    • pp.148-153
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    • 2010
  • Thermal barrier systems have been widely investigated over the past decades, in order to enhance reliability and efficiency of gas turbines at higher temperatures. Yttria-stabilized zirconia (YSZ) is one of the most leading materials as the thermal barriers due to its low thermal conductivity, thermodynamic stability, and thermal compatibility with metal substrates. In this work, rare-earth oxides with pyrochlore phases for thermal barrier systems were investigated. Pyrochlore phases were successfully formed via solid-state reactions started from rare-earth oxide powders. For the heat-treated samples, thermo-physical properties were examined. These rare-oxide oxides showed thermal expansion of $9{\sim}12{\times}10^{-6}/K$ and thermal conductivity of 1.2~2.4 W/mK, which is comparable with the thermal properties of YSZ.

Preparation of Thermal Bonding Fabric by using-low-melting-point Bicomponent Filament Yarn - Head tie - (저융점 복합사를 이용한 열융착 직물의 제조(I) - 헤드타이를 중심으로 -)

  • Ji, Myeong-Kyo;Lee, Shin-Hee
    • Fashion & Textile Research Journal
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    • v.11 no.3
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    • pp.474-480
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    • 2009
  • The purpose of this study is to prepare the hardness of polyester(PET) fabric by thermal bonding with low melting component of bicomponent fiber and to describe the change of physical properties of thermal bonded PET fabrics. The PET fabrics were prepared with regular PET fiber as warp and bicomponent fiber as weft. The bicomponent fiber of sheath-core type were composed with a regular PET core and low melting PET sheath. The thermal bonding of PET fabric was carried out in pin tenter from 120 to $195^{\circ}C$ temperature range for 60 seconds. In this study, we investigated the physical properties and melting behavior of PET fiber and the effect of the temperature of the pin tenter on the thermal bonding, mechanical properties. Melting peak of warp showed the thermal behavior of general PET fiber. However, melting peak of weft fiber(bicomponent fiber) showed the double melting peak. The thermal bonding of the PET fabric formed at about temperature of lower melting peak. The optimum thermal bonding conditions for PET fabrics was applied at $190{\sim}195^{\circ}C$ for 60seconds by pin tenter. On the other hand, the tensile strength of the PET fabric decreased with an increasing temperature of thermal bonding.

Thermo-physical Properties of the Asphalt Pavement by Solar Energy (태양열 에너지에 의한 아스팔트 포장의 열전달 특성)

  • Lee, Kwan-Ho;Kim, Seong-Kyum
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.717-724
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    • 2020
  • In general, the factors affecting the heat transfer of asphalt pavement are divided into weather factors and pavement materials. Among them, material factors include the thermophysical and surface properties. An experiment was conducted on the thermal-physical factors of asphalt, which are the basis for the pavement failure model. The thermal conductivity, specific heat capacity, thermal diffusivity, and thermal emissivity were evaluated as the thermo-physical properties of asphalt. The specimens (WC-2 & PA-13) used in the experiment were compacted with a Gyratory Compactor. The experimental results of WC-2 and PA-13 showed a thermal conductivity of 1.18W/m·K and 0.9W/m·K, specific heat capacity of 970.8J/kg·K and 960.1J/kg·K, thermal emissivity of 0.9 and 0.91, and thermal diffusivity of 5.15㎡/s and 4.66㎡/s, respectively. Experiments on the heat transfer characteristics (thermo-physical properties) of asphalt pavement that can be used for thermal failure modeling of asphalt were conducted.

Simulation and Measurement of Thermal Ablation in a Tissue-Mimicking Phantom and Ex-Vivo Porcine Liver by Using High Intensity Focused Ultrasound

  • Lee, Kang Il
    • Journal of the Korean Physical Society
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    • v.73 no.9
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    • pp.1289-1294
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    • 2018
  • The present study aims to investigate experimentally and theoretically thermal ablation in soft tissues by using high intensity focused ultrasound (HIFU) to assess tissue damage during HIFU thermotherapy. The HIFU field was calculated by solving the axisymmetric Khokhlov-Zabolotskaya-Kuznetsov equation from the frequency-domain perspective. The temperature field was calculated by solving Pennes' bioheat transfer equation, and the thermal dose required to create a thermal lesion was calculated by using the thermal dose formula based on the thermal dose of a 240-min exposure at $43^{\circ}C$. In order to validate the simulation results, we performed thermal ablation experiments in a tissue-mimicking phantom and ex-vivo porcine liver for two different HIFU source conditions by using a 1.1-MHz, single-element, spherically focused HIFU transducer. The small difference between the measured and the predicted lesion sizes suggests that the implementation of the numerical model used here should be modified to iteratively allow for temperature-dependent changes in the physical properties of tissues.