• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.178.1-178.1
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• 2011

DME is generally expected to be used as a promising clean alternative fuel to diesel fuel. DME is not natural product but a synthetic product that is produced either through the dehydration of methanol or a direct synthetic from syngas. As DME has no carbon-carbon bond in its molecular structure and is an oxygenate fuel, it's combustion essentially generates no soot. DME has such cetane number of 55~60 that it can be used as a diesel engine fuel. However, DME has low lubricity but a proven method to solve the poor lubricity is by adding lubricity improver. Therefore, the aim of this study is to develop lubricity improver of DME as a transport fuel in Korea. In this study, we investigated a possibility of fatty acid ester compounds as a candidate to improve DME lubricity as compared with current lubricity improver of diesel. We also evaluated quality characteristics, storage stability of DME with lubricity additives.

• Journal of the Korea Furniture Society
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• v.18 no.2
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• pp.106-110
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• 2007

This study was performed to find potentialities of the leaves of gingko tree (Gingko biloba L.) as a raw material for particleboard (PB) manufacturing. Various amounts of the leaves were mixed with wasted wood particles to manufacture PB. Physical and mechanical properties, such as density, internal bond (IB) strength, and modulus of rupture (MOR) of manufactured PB were not much different from those of the control board. Formaldehyde emission values decreased with increasing the amount of leaves. Especially, the formaldehyde emission of PB made with 5 percent of leaves was decreased to 1.31 mg/l, which is about 36% lower emission than that of the control. From these results, the leaves of gingko tree may be considered as an additive of lowering formaldehyde emission in a functional PB manufacturing process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.447-450
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• 2001

Abstract-Si direct bonding(SDB) technology is very attractive for both Si-on-insulator(SOI) electric devices and MEMS applications because of its stress free structure and stability. This paper presents on pre-bonding according to HF pre-treatment conditions in Si wafer direct bonding. The characteristics of bonded sample were measured under different bonding conditions of HF concentration, and applied pressure. The bonding strength was evaluated by tensile strength method. The bonded interface and the void were analyzed by using SEM and IR camera, respectively. Components existed in the interlayer were analysed by using FT-lR. The bond strength depends on the HF pre-treatment condition before pre-bonding (Min : 2.4kgf/cm$^2$∼Max : 14.9kgf/cm$^2$).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.194-197
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• 2001

Traction motors driven by high speed switching inverters is demanded higher operating temperature, severe duty cycles, higher starting current, frequent voltage transients and finally severe environmental exposure. For applications to inverter duty, traction motors needs a special insulation system, which has characteristics of increased bond strength, lower operating temperature and higher turn-to-turn insulation. In this paper, design considerations and manufacturing procedure of 200 Class insulation system with polyimde(Kapton) main insulation and silicone resin VPI process on the traction motor for EMU will be reviewed. And performance test and long life evaluation test which prove stability and long life evaluation test which prove stability and reliability of insulation system for traction motor will be introduced.

• Journal of environmental and Sanitary engineering
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• v.15 no.2
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• pp.102-111
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• 2000

As IR-sensor for detecting pollution material, the iron silicide has a fit band gap, high physicochemical stability at high temperature and good acid resistance. The growing film was formed with the Fe-Si bond and the organic compound because plasma resolved the injected precursors into various active species. In the Raman scattering spectrum, the Fe-Si vibration mode showed at 250 {TEX}$cm^{-1}${/TEX}. The FT-IR peak indicated that the various organic compounds were deposited on the films. The iron silicide was epitaxially grown to β-phase by the high energy of plasma. The lattice structure of films had [220]/[202] and [115]. The thickness of the films increased with the flow rate of silane. But rf-power increased with decreasing the thickness. The optical gap energy and the band gap were shown about 3.8 eV and 1.182∼1.194 eV. The band gap linearly increased and the formula was below: {TEX}$E_g^{dir}${/TEX}= 8.611×{TEX}$10^{-3}N_{D}${/TEX}＋1.1775

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.750-755
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• 1999

When the RC frame structures subjected to the seismic load, brittle shear failure of vertical members induces brittle collapse of whole structures. Failure mechanism like this is not desirable. So shear strengthening method to avoid this failure mechanism is needed. Recently, strengthening method using continuous fiber sheet is studied and used widely which have high elastic and high strength characteristics. In this study, RC columns which is strengthened by carbon fiber sheet in the form of tape or whole sheet were tested under the cyclic load. The parameter of this test is the amount of strengthening. As the amount of strengthening increase, strength, ductility and energy capacity increase. The failure mode of test results are shear and bond-split failure.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.475-478
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• 2005

Deicing salt has been generally used for traffic safety in winter, and the amount is increasing every year. However, deicing salt may induce the decrease of bond strength, surface scaling, and environmental pollution, etc. the purpose of this paper is to suggest the fundamental data on safety and durability for concrete structures through the estimation of chloride concentration profile and chloride diffusion coefficient. According to the test results, the critical chloride concentration($0.9\~1.2kg/m^3$)was measured at depth $23\~30mm$, and the limit chloride concentration($0.3kg/m^3$)was reached to depth 40mm. Also the surface chloride amount indicates 3.45kg per concrete unit weight, and the results showed the possibility of corrosion by deicing salt penetration.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.589-592
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• 2006

The growth in concrete structure repair has prompted major efforts to develop high early strength concrete. So, we were examined fundamental properties of cement mortar using the ordinary portland cement with rapid-setting cement. The experiments were carried out to investigate the characteristics of rapid-setting cement according to the blended ratio. The containing ratio of rapid-setting cement were changed five steps (20, 30, 50, 70, 100%) and then the flow value, setting time, compressive and bond strength test of cement mortar with RSC were investigated in this study.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.345-348
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• 2006

FRP composites which are used in strengthening existing structure are usually adhered to the concrete surface, their performance are directly affected by environmental condition such as freezing-thawing and moisture. Accordingly, it is required to evaluate bond durability between FRP composite and concrete as well as FRP materials itself. The durability characteristics of FRP composite for freezing-thawing are evaluated in this study with the variables of concrete strength, type of FRP composite, freezing-thawing conditions and freezing-thawing cycle. In addition, material durability of GFRP sheet for high temperature/high humidity condition are examined in this experimental study.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.164-167
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• 2002

SiC direct bonding technology is very attractive for both SiCOI(SiC-on-insulator) electric devices and SiC-MEMS applications because of its application possibility in harsh environments. This paper presents on pre-bonding according to HF pre-treatment conditions in SiC wafer direct bonding using PECVD oxide. The characteristics of bonded sample were measured under different bonding conditions of HF concentration, and applied pressure. The 3C-SiC epitaxial films grown on Si(100) were characterized by AFM and XPS, respectively. The bonding strength was evaluated by tensile strength method. Components existed in the interlayer were analyzed by using FT-IR. The bond strength depends on the HF pre-treatment condition before pre-bonding (Min : 5.3 kgf/$\textrm{cm}^2$∼Max : 15.5 kgf/$\textrm{cm}^2$).