• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.12 s.255
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• pp.1196-1202
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• 2006

A MEMS methanol reformer was fabricated and its performance was evaluated in the present study. Catalytic steam reforming of methanol was selected because the process had been widely applied in macro scale reformers. Conventional Cu/ZnO catalyst that was prepared by co-precipitation method to give the highest coating quality was used. The reactor structure was made by bonding three layers of glass wafers. The internal structure of the wafer was fabricated by the wet-etching process that resulted in a high aspect ratio. The internal surface of the reactor was coated by catalyst and individual wafers were fusion-bonded to form the reactor structure. The internal volume of the microfabricated reactor was $0.3cm^3$ and the reactor produced exhaust gas with hydrogen concentration at 73%. The production rate of hydrogen was 4.16 ml/hr that could generate power of 350 mW in a typical PEM fuel cell.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.10
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• pp.578-582
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• 2015

It was investigated whether the removal of nitrogen ions included livestock wastewater were increased by increasing the reaction time of livestock wastewater and microbubbles with catalyst. For this study, the nitrogen reduction system using microbubbles with catalyst was used. The two reactors were consecutively arranged, and the second reactor (Step 2) was located to next the first reactor (Step 1). Each reactor was reacted for 2 hours and air or oxygen as oxidant was fed into the reactor during operation before microbubble device. When oxygen was used, ammonia nitrogen was removed each 18.3% and 52.8% during 2 (only step 1) and 4 (step 1 and step 2) hours reactions. This value was higher than that of when air was fed. When oxygen was used, the longer the reaction time, the ammonia nitrogen removal was higher. The longer the reaction time, the higher the nitrite and nitrate was also removed such as ammonia nitrogen. Also this system was examined whether organic matter removal is effective. The total chemical oxygen demand (TCOD) removal was higher than the soluble chemical oxygen demand (SCOD). Some materials among causing substances COD were difficult to decompose biologically. Therefore, it means that it will be easy to operate the biological processes following step and reduce the concentration of organic contaminants in effluent.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.456-457
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• 2006

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.9
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• pp.885-894
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• 2012

A numerical study of a microchannel steam methane reforming reactor has been performed to understand the characteristics of heat and mass transfer. The integration of Rh-catalyzed steam methane reforming and Pt-catalyzed methane combustion has been simulated. The reaction rates for chemical reactions have been incorporated into the simulation. This study investigated the effect of contact time, flow pattern (parallel or counter), and channel size on the reforming performance and temperature distribution. The parallel and counter flow have opposite temperature distribution, and they show a different type of reaction rate and species mole fraction. As the contact time decreases and channel size increases, mass transfer between the catalyst layer and the flow is limited, and the reforming performance is decreased.

• Transactions of the Korean hydrogen and new energy society
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• v.16 no.4
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• pp.350-355
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• 2005

소형 PEMFC(Proton Exchange Membrane Fuel Cell)는 전기를 만들기 위해서 고순도의 수소를 필요로 한다. 각각의 마이크로 성형된 금속박판(스테인레스 스틸, 알루미늄)을 진공 브레이징법으로 접합하여 수소공급용 소형 개질기를 제작하였다. 마이크로 채널의 내부는 졸-겔법(스테인레스 스틸)과 양극산화법(알루미늄)으로 촉매를 지지하기 위한 다공성 $Al_2O_3$ 층을 형성시켰다. 스테인레스 스틸 박판은 에칭과 브레이징에 유리하였으나, 표면산화층 코팅을 균일하게 하여 안정적인 촉매반응을 유도하기 위한 균일한 표면 산화층 형성이 힘들었다. 반면 알루미늄 박판은 표면 산화층 형성이 상대적으로 용이했으며, 촉매를 상하지 않는 낮은 온도에서의 적층이 가능했다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.4
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• pp.285-290
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• 2007

This study has been numerically conducted to investigate the removal efficiency of Volatile Organic Compound (VOC) in photocatalytic micro-reactor. This study has placed emphasis on the improvements of the working condition of photocatalytic micro-reactor. The micro-reactor consists of 19 microchannels with a rectangular cross-section. For the validation of the current numerical study, a computation has been carried out to simulate an existing experimental study on the cylindrical reactor, which has shown a good agreement. The degradation characteristics with different inlet concentrations and velocities have been obtained. The current results can be used for the design of advanced photocatalytic micro-reactor.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.11
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• pp.870-877
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• 2008

Numerical analysis is applied to model Pt-catalyzed reaction in a micro-scale combustor fueled by butane. The reaction constants of catalytic oxidation are determined from plug flow model with the experimental data. Orders of magnitude between the chemical reaction rate and the mass transfer rate are carefully compared to reveal which mechanism plays a dominant role in the total fuel conversion rate. For various conditions of fuel flow rate and surface temperature, the profiles of Sherwood number are investigated to study the characteristics of the mass transport phenomena in the micro-tube combustor.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.6
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• pp.845-851
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• 1986

This Paper presents micro-computer simulation programs for a pneumatic control system. The simulation programs have been written in BASIC language which is suitable for 6502CPU with 48KB memory and consist of 11 programs which describe the time response and frequency response of the pneumatic actuation system. This simulation package is stored in 51/4 inch floppy diskette. The user requires no simulation expertise on the part of designer. As the result of using this simulation programs for the pneumatic control system with stabilizing tank, it has shown that the response time of the system using air as working medium takes more time to be settled but relatively stable rather than the system using helium.

• Analytical Science and Technology
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• v.17 no.3
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• pp.225-229
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• 2004

The effect of the silicon acrylate as a reactive additive on the UV-curing photopolymerization reaction was studied by micro raman technique. For the study, acrylate systems and Darocur 1173 were used as oligomer and monomers, and a photo initiator, respectively. The content of silicon acrylate was within the range of 0-3 wt%. The extent of photo-polymerization reaction as a function of depth from the air interface was obtained from the conversion ratio of acrylate double bond calculated from the intensities of measured bands at $1410cm^{-1}$ and at $1635cm^{-1}$. Micro raman spectroscopic technique can be an useful tool for the investigation of the factors, which can affect the reaction progress, such as oxygen inhibition, composition of the formulations, depth, etc.

• Journal of the Korean Vacuum Society
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• v.16 no.1
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• pp.65-73
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• 2007

The control of surface properties and spatial presentation of functional molecules within a microfluidic channel is important for the development of diagnostic assays, microreactors, and for performing fundamental studies of cell biology and fluid mechanics. Here, we present soft lithographic methods to create robust microchannels with patterned microstructures inside the channel. The patterned regions were protected from oxygen plasma by controlling the dimensions of the poly(dimethylsiloxane)(PDMS) mold as well as the sequence of fabrication steps. The approach was used to pattern a non-biofouling polyethylene glycol(PEG)-based copolymer or the polysaccharide hyaluronic acid(HA) within microfluidic channels. These non-biofouling patterns were then used to fabricate arrays of fibronectin(FN) and bovine serum albumin(BSA) as well as mammalian cells.