• 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 Korean Wood Science and Technology
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• v.26 no.2
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• pp.51-58
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• 1998

Structural changes of cellulosic fibres during the papermaking process were studied by analysis of FTIR spectra collected by the transmission method. The spectra were obtained from a carefully prepared handsheet, using a special infra-red (IR) cell suitable for evacuating the sample. The deconvolution technique was also applied for sharpening the FTIR spectra in the frequency range of the OH and CH stretching bands, which gave detailed information on the structural changes of cellulose. The intensity of some bands was decreased by predrying the sample as a result of the removal of adsorbed moisture. An increase in intensity of some bands in the frequency range of 3700 to $3200cm^{-1}$ was shown at a higher beating level. This increase in intensity was caused by changes in the crystal domain of cellulose resulting from the exposure of the crystalline area on the fibre surface.

• Mass Spectrometry Letters
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• v.4 no.4
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• pp.79-82
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• 2013

Various types of alkaloids observed in several herbal medicines were analyzed by electrospray ionization tandem mass spectrometry in positive ion mode. In the present study, MS/MS spectralpatterns were investigated for eight-types of alkaloids (aporpine, protoberberine, tetrahydroprotoberberine, benzylisoquinoline, protopine, phthalide, morpine, and bisbenzylisoquinoline). For aporpine- and protoberberine-type alkaloids, main fragmentations occurred at substituted groups on rigid ring structures, not showing ring fusion. Interesting fragmentations due to iminolization and retro-Diels-Alder (RDA) reaction were observed in MS/MS spectra of protopine- and tetrahydroprotobereberine-type alkaloids. Also, several types of fragmentations such as inductive cleavage and ${\alpha}$-cleavage, or bond cleavage between two ring structures were observed depending on their structural characteristics. These fragmentation patterns are expected to allow instant classification of the specific alkaloid type in various MS/MS spectra of alkaloids.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.532-533
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• 2006

In this research work attempts were made to study the bonding of thermoplastics with adhesives using solar energy. In order to study the curing behaviour necessary experiments were conducted under varying conditions of temperature, exposure time and power. The cured samples were then studied under the optical microscope before subjecting to tensile testing in order to study their mechanical properties. The fracture surfaces were further studied under the Scanning Electron Microscopy in order to study the microstructural changes that are taken place during curing. From the present study it is evident that curing under higher solar energy temperature, generally improves bond strength and quality of the adhesive joints when compared to other modes of curing process expect the microwave curing process.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.721-722
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• 2006

Industrialization and technique consequently in quick development the motor field small size and light weight, high efficiency and highly energy density in necessity. The permanent magnet motor small size and the research regarding the research of the torque and efficiency is coming to be active. From this paper the research regarding the quality permanent magnet motor and analysis and it was developed recently the NdFeB anisotropic bond magnet which is a high magnetic force material use, from the hazard which accomplishes power density it is high permanent magnet motor of small size and light weight it researched. The Finite Element Method it led and motor optimization. Also the experiment and analysis permanent magnet motor it is improved the motor and result it led and different it compared.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3265-3268
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• 2013

The multi-hydrogen bonded systems with the solvated electrons are investigated at the B3LYP/6-311++$G^{**}$ basis set level. The symmetrical linear geometrical characteristic is common for the dimer systems, while for the tetramer system, the tetrahedron configuration is generated. The NBO charge analyses demonstrate that the multi-hydrogen-multi-electron (mH-ne) coupling exist in these anion systems, as is supported by the electrostatic potential and the molecular orbital analyses. The positive chemical shift value of the central hydrogen ($H_c$) and the negative chemical shift value of the terminal hydrogen ($H_t$) indicate that the $H_c$ is electronegative while the $H_t$ is electropositive, respectively. Strong coupling between two central hydrogen atoms is demonstrated by the large spin-spin coupling constants. The solvated electron donates significant contributions for the stability of these systems.

• Geomechanics and Engineering
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• v.5 no.4
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• pp.331-342
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• 2013

The major factors that control the performance of reinforced soil structures is the interaction between the soil and the reinforcement. Thus it is necessary to obtain the accurate bond parameters to be used in the design of these structures. To evaluate the behavior of flyash + clay soil reinforced with a woven geotextile, 36 Unconsolidated-Undrained (UU) and 12 reinforced Consolidated-Undrainrained (CU) triaxial compression tests were conducted. The moisture content of soil during remolding, confining pressures and arrangement of geotextile layers were all varied so that the behavior of the sample could be examined. The stress strain patterns, drainage, modulus of deformation, effect of confinement pressures, effects of moisture content have been evaluated. The impact of moisture content in flyash + clay backfills on critical shear parameters was also studied to recommend placement moisture for compaction to MDD. The results indicate that geotextile reinforced flyash + clay backfill might be a viable alternative in reinforced soil structures if good-quality granular backfill material is not readily available.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.769-772
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• 2004

Very-Early-Strength Latex-Modified Concrete(VESLMC) provides the repairing material with short curing time as well as excellent bond strength, flexural strength and impermeability against water and chloride. In 2001, VESLMC introduced in Korea and improved superior material through research and development on material properties and durability. In 2003, the field test progressed for study problems of VESLMC field application. This paper introduced equipment improvement for bridge deck repair save both repair time and labor, while producing quality VESLMC structures.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.111-114
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• 2011

Waterprooping Method with sheet need to study technology and multilateral verification considering the arctic conditions as low temperature and humidity, which is the result only considered of material aspects without environmental condition in construction But there are no measures up until now. To solve this problem by using high frequency induction heating method developed waterproof sheets, cold (5 ℃ or less) can be applied in a more stable environment, water-resistant materials and construction methods were studied for development. The results of the test showed that high frequency induction heating method is effective for usability in low temperature condition and securement of proper quality than existing Waterprooping Method with sheet need.

• Journal of the Korean Society of Safety
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• v.4 no.1
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• pp.91-98
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• 1989

Today, the conception of building architecture is changing the conception that it is a kind of product and the operator of construction try to produce excellent building through developing efficiency and materials of building component. This study improves the problematic point of the extenor tile setting, through making on experiment on the method of it and purposes doing to do the exterior tile setting of good quality as it selects out of the most conformable the method. The experimental materials choose the tile of 60$\times$108mm size which are using frequently in the exterior tile setting and mortar is made from sand of Han river and potland cement, which apply the volume mixing of the ratio 1：3. The water cement ratio (W/C)is made up 62％ The methods of tile setting utilise the method of the tile setting and laying the method of the tile improved setting and laying, the method ol the pressing adhesion, the method of the improved pressing adhesion and the method of setting adherent (the method of VIBRATOR).