• 한국염색가공학회지
• /
• 제25권3호
• /
• pp.206-214
• /
• 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.

• Journal of Welding and Joining
• /
• 제32권5호
• /
• pp.80-86
• /
• 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.

• Coupled systems mechanics
• /
• 제7권6호
• /
• pp.691-705
• /
• 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.

• Journal of Advanced Marine Engineering and Technology
• /
• 제28권6호
• /
• pp.962-971
• /
• 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.

• 한국염색가공학회지
• /
• 제21권3호
• /
• pp.43-48
• /
• 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.

• 한국진공학회지
• /
• 제4권S2호
• /
• pp.58-63
• /
• 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.

• 한국분말재료학회지
• /
• 제17권2호
• /
• pp.148-153
• /
• 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.

• 한국의류산업학회지
• /
• 제11권3호
• /
• pp.474-480
• /
• 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.

• 한국산학기술학회논문지
• /
• 제21권1호
• /
• pp.717-724
• /
• 2020

일반적으로 아스팔트 포장체의 열전달에 영향을 미치는 인자는 크게 날씨와 포장체의 재료로 나뉘며, 그 중 포장체의 재료 요인으로는 열-물리적 인자(Thermophysical properties)과 포장체 표면의 인자(Surface property)으로 나뉜다. 본 연구에서는 포장체 전반적인 파손 모형에 기본이 되는 아스팔트의 열-물리적 인자에 대한 실험을 진행하였으며, 평가한 아스팔트의 열전달 특성 인자로는 열전도도(Thermal Conductivity), 비열용량(Specific Heat Capacity), 열확산특성(Thermal Diffusivity), 열방사률(Thermal Emissivity)를 평가하였다. 샘플로 사용한 표층용 혼합물 입도는 밀입도 포장 WC-2와 배수성 포장 PA-13으로 선회다짐기를 이용하여 제작하였다. WC-2와 PA-13의 실험결과로 열전도도는 1.18W/m·K과 0.9W/m·K로 나타났고, 비열용량은 970.8J/kg·K과 960.1J/kg·K으로 공극률이 더 낮은 혼합물인 WC-2가 혼합된 재료의 량이 많아 비열용량이 더 높은 나타나는 것을 알 수 있었다. 또한 열방사률은 0.9와 0.91, 열확산률은 5.15㎡/s와 4.66㎡/s으로 WC-2가 PA-13 대비 약 10% 더 빠른 열 확산을 보이는 것을 알 수 있다. 이러한 결과는 향후 아스팔트 포장의 열에너지 활용 및 열에너지에 의한 아스팔트 포장의 파손평가 및 모형개발 등에 연구 및 활용에 가장 근간이 되는 자료가 될 것이라 판단되다.

• Journal of the Korean Physical Society
• /
• 제73권9호
• /
• pp.1289-1294
• /
• 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.