• 한국식품과학회지
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• 제19권2호
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• pp.146-150
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• 1987

폴리에틸렌 글라이콜(PEG)-텍스트란 수용액 혼합물이 형성 하는 2상계에서 단백질의 분획현상에 대한 pH와 금속 이온의 영향을 검토하였다. PEG(5%)/dextran(9.5%)을 포함하는 5mM 인산 완충용액으로된 수용액 2상계에서 상층부와 하층부의 용적비를 1.0으로 하였을 때 분획계수는 각 단백질들의 등전점에서최소치를 나타 내었으며, pH가 등전점에서 벗어날 수록 단백질 분획계수는 증가하였다. 특히 pH11.0에서는 분획계수가 크게 증가하였으며 소수성이 가장 큰 BSA는 50배 ${\beta}-lactoglobulin$과 소수성이 비교적 적은 ovalbum은 각각 10배 증가하였다. 금속염 첨가는 pH3.0에서 단백질과 분획계수를 증가시키나. pH7.0과 pH11.0에서는 급격하게 감소시켰다. 단백질의 총전하가 양전하를 띠게 되는 pH3.0에서는 LiNa>K의 순으로 분획계수는 감소하였다.

• Environmental Engineering Research
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• 제11권2호
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• pp.84-90
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• 2006

UV-catalytic oxidation technique was applied for the treatment of bio-refractory character of the leachate, which is generally present in the form of adsorbable organic halogens (AOX). Destruction of AOX was likely to be governed by pH adjustment, quantitative measurement of oxidants, and the selection of oxidation model type. Peroxide induced degradation ($UV/H_2O_2$) facilitated the chemical oxidation of organic halides in acidic medium, however, the system showed least AOX removal efficiency than the other two systems. Increased dosage of hydrogen peroxide (from 0.5 time to 1.0 time concentration) even did not contribute to a significant increase in the removal rate of AOX. In ozone induced degradation system ($UV/O_3$), alkaline medium (pH 10) favored the removal of AOX and the removal rate was found 11% higher than the rate at pH 3. Since efficiency of the $UV/O_3$ increases with the increase of pH, therefore, more OH-radicals were available for the destruction of organic halides. UV-light with the combination of both ozone and hydrogen peroxide ($UV/H_2O_2$ 0.5 time/$O_3$ 25 mg/min) showed the highest removal rate of AOX and the removal efficiency was found 26% higher than the removal efficiency of $UV/O_3$. The system $UV/H2O_2/O_3$ got the economic preference over the other two systems since lower dose of hydrogen peroxide and relatively shorter reaction time were found enough to get the highest AOX removal rate.

• 설비공학논문집
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• 제18권7호
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• pp.541-548
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• 2006

A hybrid ventilation system was introduced to predict the ventilation performance of the apartments. This ventilation system was composed of the natural supply-air inlet and the forced exhaust-air outlet. Analysis was conducted by CFD technique and was performed on three ventilating flow rates; 30, 60, $120m^3/h$. As the results, residents feel comfortable thermally for $60m^3/h$. In the case of $120m^3/h$, however, residents feel uncomfortable both thermally and in air currents. In this study the energy saving for space heating is also an important factor. In the case of whole region with $180m^3/h$, residents feel comfortable at each region of the model apartment. It is shown that this hybrid ventilation system is possible method for the apartment house.

• 한국세라믹학회지
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• 제44권9호
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• pp.471-476
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• 2007

The hydration mechanism of the $3CaO{\cdot}Al_2O_3-CaSO_4{\cdot}2H_2O$ system in the presence of alkali sulfates has been investigated. The early hydration rate of $3CaO{\cdot}Al_2O_3$ was accelerated by the addition of $Na_2SO_4$ and $K_2SO_4$. This is closely related to the formation of syngenite $(CaSO_4{\cdot}K_2SO_4{\cdot}H_2O)$, and the U-phase added $K_2SO_4$ and $Na_SO_4$ in the $3CaO{\cdot}Al_2O_3-CaSO_4{\cdot}2H_2O$ system, respectively. The formation of the rigid syngenite and U-phase structure led to rapid setting and decreases the sulfate content in the liquid phase of the hydrating cement to the extent that it cannot adequately retard the hydration of $3CaO{\cdot}Al_2O_3$. In case of the alkali sulfate not added to the $3CaO{\cdot}Al_2O_3-CaSO_4{\cdot}2H_2O$ system, the ettringite was transformed to monosulfoaluminate immediately after the consumption of gypsum. However, when the alkali sulfates were added to this system, the ettringite did not transform to monosulfoaluminate immediately even though the gypsum was completely consumed. There was a stagnation period to transform to the monosufoaluminate after the consumption of gypsum because the syngenite and U-phase remained as the sulfate source.

• 분석과학
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• 제7권3호
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• pp.339-347
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• 1994

10-port 및 6-port 두 개의 밸브와 28% DC 200, SP 1700 및 Chromosorb 102 컬럼이 장착된 천연가스 분석용 복합컬럼시스템을 개발하였다. 천연가스를 이루고 있는 $N_2$, $CH_4$, $CO_2$, $C_2H_6$, $C_3H_8$, $i-C_4H_{10}$, $n-C_4H_{10}$, $i-C_5H_{12}$ 및 $n-C_5H_{12}$ 등 9개의 성분들이 모두 18분 이내에 바탕선 분리가 이루어졌다. 이 시스템의 정밀성 및 정확성을 측정하였다. 머무름 시간의 반복성은 0.02에서 0.16% 이내였고, 봉우리 넓이도 전반적으로 1% 이하의 반복성을 나타내었다. 검정곡선은 순수가스의 부분압력 주입법으로 작성되었고, 모든 성분들이 좋은 직선성을 나타내었다. 이 검정곡선을 이용하여 조성이 알려진 표준시료를 대상으로 단일컬럼과 복합컬럼 시스템에서 비교, 분석한 결과 단일 및 복합컬럼 시스템에서의 상대오차가 각각 0.5% 및 0.04% 이하의 값을 나타내었다. 복합컬럼 시스템을 도입 LNG 조성분석에 적용한 결과 복합컬럼에서의 발열량이 단일컬럼보다 낮게 평가되었고, 따라서 도입원가를 절감할 수 있음을 보였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.932-935
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• 2005

Three dimensional laser welding technology for light car body is studied. A robot, a seam tracking system and 4kW CW Nd:YAG laser are used for three dimensional robot laser welding system. The Laser system is used 4kW Nd:YAG laser(HL4006D) of Trumpf and the Robot system is used IRB6400R of ABB. The Seam tracking system is SMRT-20LS of ServoRobot. The welding joint of steel plate are butt and lap joint. The 3-D welding for Non-linear Tailored blank is performed after the observation experiments of bead on plate. Finally, the welding process for non-linear tailored blank and front side member is developed.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.147-150
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• 1996

We are developing a teleconference system based on 3D medical image. The system consists in three sub-systems : conference operating system, medical image processing system and database management system. It makes it possible efficient computer-supported coorperative work among remote multi-located hospitals. In this paper, we present functions of each subsystem that have implemented until now.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.295-296
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• 2009

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.27-28
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• 2010

• 환경위생공학
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• 제15권4호
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• pp.26-34
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• 2000

In order to treat the dyeing wastewater, the $UV/TiO_2/H_2O_2$ system was investigated, and proper pretreatment methods were examined to reduce the load on the system considering economical and technical efficiency. The results of this study were as follows: 1. $UV/TiO_2/H_2O_2$ system with pretreatment process was adopted, the result of Chemical coagulation and pH control units was $pH{\;}11{\;}{\rightarrow}{\;}coagulation{\;}{\rightarrow}{\;}pH{\;}4$ and the optimum dosage of $FeCl_3$ was $600mg/{\ell}$. 2. Proper dosage of $TiO_2$ in the $UV/TiO_2/H_2O_2$ system with pretreatment process was $2g/{\ell}$ and $H_2O_2$ was $1000mg/{\ell}$, UV contact time was 20min to get $200mg/{\ell}$ of $COD_{Cr}$.