• 한국세라믹학회지
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• 제31권3호
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• pp.265-274
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• 1994

Intermetallic Ti-Si system ceramics were synthesized from stochiometric mixtures of titanium and silicone powders in vacuum by Self-propagating High-temperature Synthesis(SHS). In each cases of Ti5Si3, Ti5Si4 and TiSi, and TiSi2 synthesis, 20wt% product dilution, direct ignition and SHS chemical furnace method were employed. The combustion modes, which were observed during the synthesis process by using the high speed camera, of Ti5Si3, Ti5Si4, TiSi, and TiSi2 exhibit spin, osciallatory, steady-state, and spin combustion, respectively. With increasing Ti/Si molar ratio an decrease of combustion velocities was found. From the results on the measurement of the flexural strength, the specimen hot pressed at 135$0^{\circ}C$ for 30 min using synthesized Ti5Si4 powders showed the highest flexural strength at 215 MPa.

• 한국수소및신에너지학회논문집
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• 제15권4호
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• pp.283-290
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• 2004

The single-step process for conversion of syngas to DME give higher conversion than the syngas-to-methanol process. This arises because of a synergy among the three simultaneous reaction, methanol synthesis, methanol dehydration and water gas shift reaction, in the process. we would find the optimal condition of the process which these advantages. The optimal condition of DME synthesis reaction over a commercial $Cu/Zn/Al_2O_3$ catalyst and Hybrid catalyst in a fixed bed reactor. The syngas-to-dimethyl ether conversion was examined on various reaction condition (Temperature 473~553K, $H_2/CO$ ratio 1~3, Pressure 30'50atm, GHSV 1000~4000).

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.168-173
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• 2000

Flame aerosol synthesis technology refers to the formation of fine particles from gases in flame and is widely used in practical materials processing. In this paper, an experimental investigation was performed on growth of the silica particles that were generated in $H_2/O_2$ Diffusion Flame by the direct injection or TEOS using Electro-spraying method. in this flame aerosol synthesis, four main parameters or nos interaction (flame temperature, residence time or particle in flame, TEOS flow rate, applied voltage) for particle generation and growth was investigated along the axial direction above the burner. A fairly monodisperse non-aggregated particles were successfully obtained.

• 한국분말재료학회지
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• 제13권6호
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• pp.432-438
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• 2006

Aluminum nitride (AlN) nanopowders with low degree of agglomeration and uniform particle size were synthesized by carbothermal reduction of alumina and subsequent direct nitridization. Boehmite powder was homogeneously admixed with carbon black nanopowders by ball milling. The powder mixture was treated under ammonia atmosphere to synthesize AlN powder at lour temperature. The effect of process variables such as boehmite/carbon black powder ratio, reaction temperature and reaction time on the synthesis of AlN nanopowder was investigated.

• 한국정밀공학회지
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• 제19권9호
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• pp.34-40
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• 2002

Machining accuracy is affected by quasi-static errors of machining center. Since machine errors have a direct influence upon both the surface finish and geometric shape of the finished workpiece, it is very important to measure the machine errors and to compensate these errors. The laser measurement method for identifying geometric errors of machine tool has the disadvantages such as high cost, long calibration time and usage of volumetric error synthesis model. Accordingly, this paper deals with analysis of the geometric errors of a machine tool using ball bar test without using complicated error synthesis model. Statistical analysis method was adopted in this paper for deriving geometric errors using hemispherical helix ball bar test. As a result of experiment, geometric errors of the vertical machining center are compensated by 88%.

• Food Science and Biotechnology
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• 제14권3호
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• pp.368-370
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• 2005

Citronellyl valerate was synthesized by a lipase from a Rhizopus sp strain isolated and the lipase produced, at UNICAMP, Brazil. Direct esterification was performed in a solvent-free medium to produce the flavor ester. Response surface methodology was used to optimize the process with respect to the substrate molar ratio and lipase concentration. The results show that the synthesis of citronellyl valerate can be carried out in a solvent-free medium, the maximum ester conversion rate achieved being 91.5% after 48 hours of reaction time.

• Archives of Pharmacal Research
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• 제9권3호
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• pp.153-156
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• 1986

The triterpenoid isolated from the seeds of Phytolacca plants was confirmed to be acetylaleuritolic acid rather than acetylepialeuritolic acid by direct comparison with synthetic compounds.

• Bulletin of the Korean Chemical Society
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• 제29권6호
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• pp.1099-1100
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• 2008

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2010년도 춘계학술 발표회
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• pp.150-150
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• 2010

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2000년도 추계학술대회 및 발표대회 강연 및 발표논문 초록집
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• pp.26-26
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• 2000