• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.375-379
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• 1999

This study was designed to develop non-thermal pasteurized fresh apple juice by applying pulsed electric field (PEF) treatment. The effect of non-thermal PEF treatment on physicochemical and sensory properties of apple juice was examined by measuring changes in vitamin C contents, colors, flavors and sensory properties. Color of PEF and heat treated apple juices was not significantly different from each other. Vitamin C content of PEF treated apple juice was close to that of fresh apple juice, but was much higher than that of heat treated apple juice. Heat treated apple juice lost 70% of flavor components, whereas PEF-treated apple juice lost only 15%. Sensory scores of PEF treated apple juice were significantly higher than heat-treated one in flavor, taste and overall acceptability. In conclusion, PEF treated apple juice had superior physico-chemical and sensory properties to heat-treated one.

• Journal of the Korean Magnetics Society
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• v.21 no.3
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• pp.104-107
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• 2011

We measured signals at the "Guan" region of a radially arterial pulse using the prototype of a clamping pulsimeter equipped with a Hall effect device, which is passed signals through the voltage detecting hard ware system. The important four different measuring times of the period, systolic, reflective, and notch peaks for a temporally pulse signal are obtained and compared each other from the analysis for an arbitrary pulse wave of one position of small size permanent magnet. It is possible to measure the reproducible pulse rate and blood pressure by using the cuffless clip type pulsimeter without an unpleasant oppressive feeling due to the use of pressurization.

• Journal of the Korean Magnetics Society
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• v.22 no.1
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• pp.27-31
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• 2012

Two radially arterial pulses of both hands using the prototype of a clamping clip pulsimeter equipped with permanent magnet and Hall device are compared and analyzed. The phase difference of two pulse wave signals is dominantly presented from the simultaneous measuring clinical pulse wave signals for twenty two male participants at their 20's. It is possible to analyze that the fast and slow pulse wave for right hand and left hand depend on the muscle property of arms rather than the total length of blood vessel due to cardiovascular circulatory system.

• Journal of the Korea Concrete Institute
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• v.13 no.4
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• pp.346-353
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• 2001

This research investigates the mixture proportioning of waste newsprint paper fiber for thin-cement product. Waste newsprint paper fibers obtained through shredded mechanically by a dry process. Waste newsprint paper fiber reinforced cement composites was manufacted by slurry-dewatering method. The waste newsprint paper fiber reinforcement conditions (fiber mass fraction, level of substitution of virgin fibers, level of fiber beating) and processing variables (pressed, unpressed) are optimized through experimental studies and statistical analyses based on factorial design of experiments and analyses of variance. The optimized recycled waste newsprint paper fiber reinforced cement composites were technically evaluated. The results are shown to possess acceptable properties and strong potentials of the recycling of waste newsprint paper of the reinforcement of thin-cement products.

• Food Engineering Progress
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• v.15 no.3
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• pp.209-213
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• 2011

Changes of rancidity of soybean powder from Yeonhaeju (Bazaz) during storage were evaluated by TBA, and compared with those of Korean soybean (Baektae). Lipoxygenase (LOX) in the soybean powder was inactivated by high pressure processing (HPP) to increase the stability of soybean powder during storage. The level of inactivation of LOX was measured by spectrophotometer at 234 nm. HPP decreased the activity of LOX in the soybean powder of Baektae, compared to that of the control (i.e., soybean powder without HPP treatment) of Baektae, while TBA values of both HPP treated Baektae and the control were increased up to 24 days of storage. However, in case of Bazas, both LOX activity TBA values decreased after HPP treatment, compared to those of controls. The antioxidant compounds in both soybeans were measured and quantitatively evaluated by on-line $ABTS^{+}$ assay. Based on the trolox equivalent (TE) value at the retention time 38.2 and 40.1 min, the antioxidant components in Bazaz were higher than that of Baektae. It might indicate that relatively lower TBA values of HPP treated Bazaz was due to lower LOX activity as well as higher antioxidant compounds in the species.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.8
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• pp.735-743
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• 2011

In this study, the distribution of surface pressure was measured in a steady state on a turbine blade which was moved the injected region and receded the stagnation region using a linear cascade apparatus. Axial-type blades were used and the blade chord was 200mm. The rectangular nozzle was applied and its size was $200mm{\times}200mm$. The experiment was done at $3{\times}10^5$ of Reynolds number based on the chord. The surface pressures on the blade were measured at three different nozzle angles of $58^{\circ}$, $65^{\circ}$ and $72^{\circ}$ for off-design performance test. In addition, three different solidities of 1.25, 1.38 and 1.67 were applied. From the results, the low solidity caused the low pressure on the blade suction surface at entering region and the reverse rotating force was generated at the low nozzle angle. The positive incidence also made the pressure lower on the suction surface at entering region.

• Polymer(Korea)
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• v.32 no.4
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• pp.328-333
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• 2008

The osmotic delivery systems are based on osmosis. The transverse diffusion of water through a porous membrane from a medium with a low osmotic pressure to a medium with a high osmotic pressure. Nifedipine tablet dosage forms of Procardia $XL^{(R)}$(Pfizer) and $Adalat^{(R)}$(Bayer) are commercialized systems of this type that push-pull osmotic tablet operates successfully in delivering water-insoluble drugs. We prepared osmotic pellet system by fluidized bed coating method, and model-drug used nifedipine. The osmotic pellet system was composed of the core material. the swelling and osmotic pressure layer, the drug coating layer, and the porous membrane. This work is performed to investigate the effect of different factors, such as composition and thickness of membrane. The osmotic pellet has been successfully prepared by fluidized bed coating technology. The drug release behavior depended on the increase of CA ratio and thickness in porous membrane. The morphology of the osmotic pellet before and after the dissolution test were observed by SEM. In conclusion, we found that the drug release of osmotic pellet depended on the composition and coating thickness of porous membrane.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.2099-2101
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• 2004

본 연구에서 제안하는 마이크로 시스템은 열공압 방식으로 구동되고 제작비용이 저렴한 indium tin oxide (ITO) 및 polydimethylsiloxane (PDMS)로 제작되었다. 제안된 마이크로 밸브와 마이크로 펌프의 구조는 ITO 히터, SU-8 층, PDMS membrane, 그리고 PDMS 채널로 구성 되어 있다. 제안된 마이크로 펌프와 마이크로 밸브는 제작 공정 및 구조가 간단하고 값이 저렴하며, 마이크로 펌프와 마이크로 밸브를 같은 기판 위에 쉽게 직접화할 수 있는 장점을 가진다. 마이크로 밸브의 유량은 채널 폭에 비례하며 밸브가 closing 되는 전력은 채널의 폭과 상관없이 100 mW이다. 마이크로밸브의 ITO 히터의 온-오프에 따라 유량이 매우 잘 제어되었다. 제안된 마이크로 펌프의 경우, 히터의 인가 펄스 전압이 증가함에 따라 유량은 선형적으로 비례 증가함을 관찰할 수 있다. 마이크로 펌프의 최대 유량은 펄스 전압과 duty 비가 55V와 10%일 때 6 Hz에서 78 nl/min이 측정 되었다.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2374-2376
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• 2005

본 연구에서 제안한 microfluidic system은 열공압 방식으로 구동되고 indium tin oxide (ITO) 및 polydimethylsiloxane(PDMS)로 제작하여 공정이 간단하고 비용이 저렴하여 일회용으로 사용이 가능하며 투명한 장점을 갖는다. 또한 마이크로 펌프는 인-채널 구조의 마이크로 밸브와 동일한 공정으로 제작하였다. 제안된 마이크로 펌프는 인-채널 구조의 마이크로 밸브와 같은 기판 위에 쉽게 집적하여 제작할 수 있다. 마이크로 펌프의 pumping rate는 인가 펄스 전압의 주파수와 duty비를 변화시켜 최적화하였다. Duty 비가 1%이고 주파수가 2 Hz일 때 최대 pumping rate를 보였으며 이때 pumping rate는 26.18nl/min이였다. 마이크로 밸브는 ITO 히터에 전력을 인가함으로서 유량의 on/off 제어가 잘 됨을 확인할 수 있었고 유체를 closing하기 위해 필요한 전력은 100mW이다.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.329-334
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• 1997

석탄화력발전소 폐기물인 석탄회로 포집한 세슘의 환원분위기(He+4% H$_2$)하에서 고온안정성 분석을 위하여 몰비를 0.1에서 1.5까지 변화시켜 제조한 시료를 머플로에서 열처리 및 XRD로 분석하였다 Cs/Al의 몰비가 증가할 수록 세슘 포집량이 증가하였다. 세슘 포집량 0.48(g-Cs$_2$O/g-fly ash) 이상에서 부터 pollucite 상 이외에 CsAlSiO$_4$상이 나타나기 시작하였고 세슘 포집량이 증가할 수록 CsAlSiO$_4$ 상이 증가하였다. 세슘 포집량 0.15(g-Cs$_2$O/g-fly ash) 까지 세슘의 휘발로 인한 무게감량은 없었고, 포집량 0.32(g-Cs$_2$O/g-fly ash)부터는 포집량이 증가할 수록 무게감량이 증가하였다. 이는 세슘 포집량이 증가할 수록 세슘 증기압이 큰 CsAlSiO$_4$상이 증가하기 때문인 것으로 사료된다.