• 한국의류산업학회지
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• 제17권3호
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• pp.462-475
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• 2015

This paper investigated the characteristics of the physical properties of woven fabrics according to the yarn structure and fibre property. It was found that wicking property of woven fabrics made of sheath/core hybrid yarn were better than those of siro spun and siro-fil hybrid yarns, which was caused by platform for transport of moisture vapor by filaments on the core part of sheath core hybrid yarns. In drying property, the fabric specimen woven by PP/Tencel sheath core hybrid yarns as a warp and Coolmax/Tencel spun yarn as a weft showed quick drying property, which was caused by the sheath core hybrid yarn structure as drainage of water moisture and coolmax fibre characteristics as quick dry material. Concerning to breathability and thermal conductivity as heat transport phenomena, it was observed that breathability of fabrics woven with hybrid yarns such as sheath core and siro-fil in the warp and hi-multi filaments in the weft showed the lowest water vapor resistance, which was explained as due to for air gap in the fibres of the spun yarns to restrict the wet heat transport from perspiration vapor. Thermal conductivities of the fabrics woven with PET/Tencel siro-fil yarns in the weft and hybrid yarns such as sheath core and siro-fil in the warp revealed the highest values, which was observed as due to higher thermal conductivity of PET than PP and more contact point between fibres in the siro-fil and sheath core hybrid yarns.

• 대한의용생체공학회:의공학회지
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• 제36권1호
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• pp.7-15
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• 2015

The egg white phantom is a thermal lesion visualization phantom able to illustrate a thermal lesion. It is often used to evaluate the performance of HIFU and is less expensive than the BSA phantom. This study determined the optimal phantom composition for evaluated therapeutic ultrasound machines by varying the egg white concentration in the egg white phantom and demonstrated its utility as a therapeutic ultrasound phantom. The egg white phantom at varying egg white concentrations (10-40% in 10% intervals) was fabricated, and its thermal properties and acoustic properties were assessed. In addition, the size and shape of the formed lesion were compared between the egg white phantom and bovine liver tissue according to the electrical power. The results showed that 30% egg white phantom was optimal for the performance evaluation due to its thermal and acoustic properties. The generated thermal lesions formed sequentially as a cigar, ellipse, tadpole, and cone shapes according to the electrical power; a similar tendency was observed in the liver tissue. Hence, we conclude that the egg white phantom will prove useful in quantitatively evaluating the thermal effects of therapeutic ultrasound.

• 한국염색가공학회지
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• 제22권1호
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• pp.43-50
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• 2010

The thermal treatment for carbon nanotube was applied to remove the water, metal catalyst and other impurities in carbon nanotube. The surface of carbon nanotube was changed into open structure with acid treatment by mixed solution of $HNO_3$ and $H_2SO_4$. The dispersion property of the functionalized and modified carbon nanotube was assessed with naked eyes by dispersing it in DMF. Carbon nanotube mixd polyurethane film was made to estimate the dispersion property by reflectance of the film with UV-Vis spectrometer. Also the internal structure of carbon nanotube was observed with SEM and TEM and thermal pyrolysis property of the carbon nanotube was measured by TGA and DSC. The surface modification of carbon nanotube by thermal and acid treatments improved the dispersion property of carbon nanotube/polyurethane mixed materials.

• 대한토목학회논문집
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• 제29권5A호
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• pp.531-541
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• 2009

본 연구에서는 강도수준(30, 50 및 70 MPa)에 따른 고유동 자기충전 콘크리트의 수화발열 특성을 알아보기 위하여 2성분계 및 3성분계 고유동 자기충전 콘크리트를 제조하여 일반콘크리트와 수화열, 응결 및 역학적 특성을 분석 고찰 하였으며, 콘크리트에 사용된 분체에 대한 미소수화열량을 측정하여 얻은 분체의 열특성값, 간이단열온도실험을 실시하여 얻은 콘크리트의 열특성값 및 콘크리트에 사용된 재료의 일반적인 열특성값을 간편한 방법의 추정식을 이용하여 콘크리트 단열온도를 추정하였다. 또한, 온도해석에 의하여 얻어진 수화열 및 단열온도 특성값을 MIDAS CIVIL 06 프로그램을 이용하여 3차원 온도응력 해석을 실시하여 고유동 자기충전 콘크리트의 수화발열 특성 및 수화열에 의한 온도응력을 분석 고찰하였다.

• 반도체디스플레이기술학회지
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• 제11권2호
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• pp.75-80
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• 2012

Polymer composites which have electrical properties have been studied in various industries. The Multi-walled carbon nanotube (MWCNT) are thought to be reinforcements for polymers because of their high aspect ratio and specially mechanical, thermal and electrical properties. We introduced MWCNT and impact modifier in order to improve thermal and mechanical properties of Polyphenylene sulfide (PPS) and give electric characteristic to PPS. The thermal properties were investigated by Differential scanning calorimeter (DSC) and Thermogravimetric analysis (TGA). The morphology, mechanical properties and electrical characteristic were performed by Field emission scanning electron microscopy (FE-SEM), Izod impact tester and surface resistance meter. As a result, we could find that the PPS/MWCNT composites have high conductivity and good mechanical properties than neat PPS resin.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 추계학술발표대회 논문집
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• pp.21-24
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• 2003

In general, to enhance physical properties of PET-layered silicate nanocomposites $(P_{et}LSNs)$, it has been well known that the organic modifiers should introduce into gallery regions. However, the organic modifiers in$(P_{et}LSNs)$ may result in thermal decomposition by melt processing at high temperature, and it necessarily lead to deteriorate various physical properties of final products. Therefore, in this study, $(P_{et}LSNs)$ excluding and including organic modifiers were prepared by solution method $(S-P_{et}LSNs_{eom} and S-P_{et}LSNs_{iom})$ and we (focused on the effects of the organic modifiers in $P_{et}$ LSNs with exfoliation structure on the crystallization behaviors, the optical transparency, the thermal stability and the mechanical property. The absence and existence of organic modifiers in $S-P_{et}LSNs_{eom} and S-P_{et}LSNs_{iom}$ were investigated by EA and TGA, and nano-structure of silicate layers in $S-P_{et}LSNs$ was evaluated by using WXRD, SAXS and TEM. $S-P_{et}LSNs_{eom} and S-P_{et}LSNs_{iom}$ were mixed with neat PET as masterbatches by melt method $(M-P_{et}LSNs_{eom} and M-P_{et}LSNs_{iom})$, and also neat PET was mixed with organically modified layered silicates (OLS) by conventional direct melt method $(D-P_{et}LSNs) at 270^{\circ}C$. As results, it was found that $M-P_{et}LSNs_{eom}, M-P_{et}LSNs_{iom}, and D-P_{et}LSN$ showed a exfoliated structure and exhibited faster crystallization rate, better thermal stability and mechanical property than those of neat PET due to the dispersed and detaminated silicate layers in PET matrix. Whereas, considering organic modifiers effect, $M-P_{et}LSNs_{eom} and D-P_{et}LSN$ exhibited slower crystallization rate, poorer optical, thermal and mechanical properties, in comparison to $M-P_{et}LSNs_{eom}> due to the thermal decomposition of organic modifier in $D-P_{et}LSNs$ during melt method.

• 대한기계학회논문집B
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• 제32권10호
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• pp.800-809
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• 2008

Scanning Thermal Microscope (SThM) is the tool that can map out temperature or the thermal property distribution with the highest spatial resolution. Since the local temperature or the thermal property of samples is measured from the extremely small heat transferred through the nanoscale tip-sample contact, improving the sensitivity of SThM probe has always been the key issue. In this study, we develop a new design and fabrication process of SThM probe to improve the sensitivity. The fabrication process is optimized so that cantilevers and tips are made of thermally grown silicon dioxide, which has the lowest thermal conductivity among the materials used in MEMS. The new design allows much higher tip so that heat transfer through the air gap between the sample-probe is reduced further. The position of a reflector is located as far away as possible to minimize the thermal perturbation due to the laser. These full $SiO_2$ SThM probes have much higher sensitivity than that of previous ones.

• 한국태양에너지학회 논문집
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• 제26권4호
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• pp.83-91
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• 2006

As a demand for sustainable development rises, the preference for earth house (earth construction) increases gradually. However, there are few data for predicting and evaluating the thermal environment and indoor air quality of earth house. Thus, this study aims to measure thermal properties(thermal conductivity, density and specific heat) and pollutants emission intensities(formaldehyde and volatile organic compounds) of current main earth construction materials and make a comparison between earth and cement construction materials. As results, quantitative thermal properties and pollutants emission intensities of current main earth construction materials are shown.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.250-252
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• 2003

This paper is the estimation of the thermal property for the backfill materials according to the experimental measurements both a laboratory and field test.

• 융복합기술연구소 논문집
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• 제5권1호
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• pp.13-17
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• 2015

In wafer level molding progress, the thermal releasing failure phenomenon is shown up as the important problem. This phenomenon can cause the problem including the warpage, crack of the molded wafer. The thermal releasing failure is due to the insufficiency of adhesion strength degradation of the molding tape. To solve this problem, we studied experimental method increasing the release property of the molding tape through the plasma surface treatment on the wafer substrate. In this research, the vacuum plasma treatment system is used for release property improvement of the molding tape and controls the operating condition of the hydrophilic($O_2$, 100kW, 10min) and hydrophobic($C_2F_6$, 200kW, 10min). In order to perform the peeling test for measuring the releasing force precisely, we remodel the micro scale material property evaluation system developed by Korea institute of industrial technology. In case of hydrophilic surface treatment on the wafer substrate, we can figure out the releasing property of molding tape increase. In order to grasp the effect that it reaches to the release property increase when repeating the hydrophilic treatment, we make an experiment with twice treatment and get the result to increase about 12%. We find out the hydrophilic surface treatment method using plasma can improve releasing property of molding tape in the wafer level molding process.