• 한국세라믹학회지
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• 제32권1호
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• pp.131-139
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• 1995

In order to improve transmittance and response properties, various compositions of light controllable films were prepared by phase separation method. The optical and response properties were measured with the variation of PMMA/suspension ratio and block copolymer/light polarizing particles. According to the increase of the PMMA/suspension ratio, the separated droplets of suspension were interconnected in the film. Decay time was 2.6 sec when PMMA/suspension ratio was 0.5 : 1 and ΔT(difference of the transmittance at OFF/ON states) was reduced with increasing of the ratio of PMMA/suspension. On block copolymer/light polarizing particles ratio variation, the highest transmittance of the film was 67.4% when its ratio was 0.6 : 1 and decay time was varied from 2.15 to 46.6 sec as block copolymer content increased 0.2 : 1 to 1 : 1.

• Fibers and Polymers
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• 제6권4호
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• pp.289-296
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• 2005

Biodegradable nanocomposites were prepared by mixing a polymer resin and layered silicates by the melt intercalation method. Internal structure of the nanocomposite was characterized by using the small angle X-ray scattering (SAXS) and transmission electron microscope (TEM). Nanocomposites having exfoliated and intercalated structures were obtained by employing two different organically modified nanoclays. Rheological properties in shear and extensional flows and biodegradability of nanocomposites were measured. In shear flow, shear thinning behavior and increased storage modulus were observed as the clay loading increased. In extensional flow, strain hardening behavior was observed in well dispersed system. Nanocomposites with the exfoliated structure had better biodegradability than nanocomposites with the intercalated structure or pure polymer.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.255-257
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• 2001

In this paper, the silicon rubber insulator for transmission line was experimented for 1,000 hours aging test in salt-fog condition. To evaluate and examine the aging properties of silicon rubber insulator for test, the leakage current of surface was measured. Also hydrophobicity and scanning electron microscopy were compared with initial and aged sample respectively. Above results, we can confirm that the surface properties of silicon rubber insulator easily aged by salt-fog condition.

• 동력기계공학회지
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• 제18권3호
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• pp.100-105
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• 2014

This study is to investigate the effect of thermo mechanical treatment on the mechanical properties of 316L stainless steel. ${\alpha}^{\prime}$ and ${\varepsilon}$-martensite was formed by deformation. With increasing number of thermo mechanical treatment, volume fraction of martensite was increased rapidly, and then unchanged. With increasing number of thermo mechanical treatment, hardness and strength was increased rapidly, and then unchanged while elongation was decreased rapidly, and then unchanged. With increasing volume fraction of martensite formed by thermo mechanical treatment, hardness and strength was increased rapidly, elongation was decreased rapidly. Thus, hardness, strength and elongation of thermo mechanical treated 316L stainless steel was strongly affected by martensite formed by thermo mechanical treatment. Good combination of strength and elongation was obtained from thermomechanical treatment.

• Korea-Australia Rheology Journal
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• 제20권4호
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• pp.227-233
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• 2008

High impact polystyrene (HIPS)/organoclay nanocomposites via in situ polymerization were synthesized and their rheological properties were investigated. For the study, two types of organoclays were used: a commercially available organoclay, Cloisite 10A (C10A), and a laboratory-prepared organoclay having a reactant group, vinylclay (ODVC). The X-ray diffraction and transmission electron microscopy experiments revealed that the HIPS/ODVC nanocomposite achieved an exfoliated structure, whereas the HIPS/C10A nanocomposite achieved an intercalated structure. In the small-amplitude oscillatory shear experiments, both storage modulus and complex viscosity increased with increasing organoclay. A pronounced effect of the organoclay content was observed, resulting in larger storage modulus and stronger yield behavior in the low frequency region when compared to neat HIPS. The crossover frequencies associated with the inverse of a longest relaxation time decreased as the organoclay content increased. Over a certain value of ODVC content, a change of pattern in rheological properties could be found, indicating a solid-like response with storage modulus greater than loss modulus at all frequencies.

• Journal of Magnetics
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• 제6권4호
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• pp.126-128
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• 2001

The effect of rapid thermal anneal (RTA) has been investigated on the properties of an FeMn exchange-biased magnetic tunnel junction (MTJ) using magnetoresistance and I-V measurements and transmission electron microscopy (TEM). The tunneling magnetoresistance (TMR) in an as-grown MTJ is found to be ∼27%, while the TMR in MTJs annealed by RTA increases with annealing temperature up to 300$\^{C}$, reaching ∼46%. A TEM image reveals a structural change in the interface of A1$_2$O$_3$layer for the MTJ annealed by RTA at 300$\^{C}$. The oxide barrier parameters are found to vary abruptly with annealing time within a few ten seconds. Our results demonstrate that the present RTA enhances the magnetoresistive properties of MTJs.

• Carbon letters
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• 제16권1호
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• pp.34-40
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• 2015

In this study, in order to improve the thermal and electrical properties of epoxy/graphene nanoplatelets (GNPs), surface modifications of GNPs are conducted using silane coupling agents. Three silane coupling agents, i.e. 2-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane (ETMOS), 3-glycidoxypropyltriethoxysilane (GPTS), and 3-glycidoxypropyltrimethoxysilane (GPTMS), were used. Among theses, GPTMS exhibits the best modification performance for fabricating GNP-incorporated epoxy composites. The effect of the silanization is evaluated using transmission electron microscopy (TEM), scanning electron microscopy, thermogravimetric analysis, and energy dispersive X-ray spectroscopy. The electrical and thermal conductivities are characterized. The epoxy/silanized GNPs exhibits higher thermal and electrical properties than the epoxy/raw GNPs due to the improved dispersion state of the GNPs in the epoxy matrix. The TEM microphotographs and Turbiscan data demonstrate that the silane molecules grafted onto the GNP surface improve the GNP dispersion in the epoxy.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.104-105
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• 2008

According to previous report, aged sleeves of old transmission line showed several defaulted installation patterns, which is biased or corrosive-fractured of steel sleeve installed cases. The latter case occupied almost 25 percent of investigated aged sleeves. These defects can cause serious accidents such as rapid increasing of sag or falling out of overhead conductor from sleeves. This paper studies thermal properties and tension for ACSR conductor in case of fractured steel sleeve model. The detailed results were presented in the text.

• Journal of electromagnetic engineering and science
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• 제12권2호
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• pp.161-165
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• 2012

The electrical properties of pig internal organs including lung, liver, heart, kidney, blood, stomach, and small intestine are measured using an open-ended coaxial probe and an improved virtual transmission-line model. The measured complex permittivities of the pig organs are compared with the given values of the corresponding human organs. A similarity between these values is confirmed. For organs such as lung, liver, heart, and kidney that have regular texture and contents, the complex permittivities are almost identical to those of the corresponding human organs. The complex permittivities of human and pig blood are also very close in value. However, relatively large deviations are observed for the cases of stomach and small intestine because the internal contents of these organs significantly affect the measured electrical properties.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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• pp.117-119
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• 2004

To improve mean-life and reliability of power cable in this study, we have investigated chemical properties showing by changing the content of carbon black that is semiconductive additives for underground power transmission. Specimens were made of sheet form with the three of existing resins and the nine of specimens for measurement. Chemical properties of specimens was measured by FT-ATR (Fourier Transform Attenuated Total Reflectance). The condition of specimens was a solid sheet. We could observe functional group (C=O, carbonyl group) of specimens through FT-ATR. From these experimental result, the concentration of functional group (C=O) was high according to increasing the content of carbon black. We could know EEA was excellent more than other specimens from above experimental results.