• Clean Technology
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• v.25 no.3
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• pp.189-197
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• 2019

In this study an optimization of the preparation conditions of activated carbon with a ternary metal ion material to treat $H_2S$, which is classified as a representative odor substance, was carried out. For a metal ion material for enhancing the adsorption performance of hydrogen sulfide, performance enhancement was confirmed by combining Li and Fe or a ternary combination (K, Li, Fe) based on KI, which is a substance promoting hydrogen sulfide adsorption performance. Also, it was determined by XRD analysis that the reaction of each active substance with $H_2S$ was because of binding. The adsorption performance increased more than 3 times with heat treatment of the adsorbent with nitrogen compared with heat treatment with air. The maximum adsorption constant ($q_m$) value of the optimum adsorbent was 97.07, which is 6 times higher than that of the existing K-based impregnated activated carbon. It was confirmed that the objective adsorption amount ($0.3g\;g^{-1}$) was secured by an equilibrium between the mass transfer rate and adsorption rate. From the results, it was confirmed that the performance improvement was noticeable even when activated carbon with a reagent grade activated carbon particle size was modified. It was confirmed that the adsorption performance exists at high relative humidity levels of 60 and 100%, and the optimized preparation can be applied to a wet process such as a scrubber downstream.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.173-177
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• 2011

In this study, the formation of $AlPO_4$-type porous materials from alum sludge was investigated. The materials were synthesized by the reaction of aluminum hydroxide and phosphoric acid with an organic template. Cationic surfactant, natural humic acid, and amino acids were used for the organic template. The residual organic templates were removed by calcination at $600^{\circ}C$ in the air. Powder X-ray diffraction patterns showed the charicteristic patterns of the $AlPO_4$-type porous materials. The morphology of the material was examined using a scanning electron microscopy. The coordination environment of $Al^{3+}$ ion was investigated by $^{27}Al$ MAS NMR technique. Both tetrahedrally and octahedrally coordinated$Al^{3+}$ ions were found in the as-synthesized samples while all $Al^{3+}$ ions were tetrahedrally coordinated in the calcined products. The development of mesopore in the solid material was confirmed by the measurement of BET specific surface area. Finally, they were used for removal of toxic formaldehyde from the air and the formaldehyde molecules were adsorbed on the surface of pores. In conclusion, $AlPO_4$-type porous materials from alum sludge might be applicable in the removal of toxic volatile organic compounds from the air.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.375-376
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• 2003

자동차 운행의 급증과 유류 및 유기 용제의 사용 확대로 인해 휘발성유기화합물질(Volatile Organic Compounds : VOC)의 배출은 증가추세에 있다. VOC는 오존 등 광화학스모그 원인 물질일 뿐만 아니라 발암성 등의 유해 물질, 지구온난화와 성층권 오존층 파괴의 원인물질, 대기 중 악취물질로서 환경 및 건강에 영향을 초래하여 VOC 대한 규제관리 및 감축에 대한 연구가 필요한 실정이다. 상용화된 VOC 저감기술로는 고온산화, 촉매산화, 흡착 등의 방법이 있으며 이 기술들은 농도, 에너지 requirement, 비용 및 부산물 처리 등의 문제가 있다. (중략)

• Proceedings of the Membrane Society of Korea Conference
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• 1995.06a
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• pp.73-92
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• 1995

환경오염은 인간이 지구상에서 산업활동을 시작한 이래 계속되어 오고 있는 문제인데, 최근에 들어서 전세계적으로 산업화가 가속되고 또한 인구의 급격한 증가로 인하여 매우 심각한 국면을 맞이하고 있다. 환경오염은 원재료를 가공하여 인간의 일상생활에 필요한 물픔을 생산하는 전 산업 영역에서 발생하고 있는데 이러한 환경오염은 토양오염, 수질오염, 대기오염의 세 가지로 분류할 수 있다. 오늘날의 심각한 환경오염은 환경기술이라는 신조어를 만들게 되었는데, 이는 환경오염을 적게 유발시키는 생산공정을 의미하는 저오염 생산기술(clean technology)과 생성된 오염 물질을 분리 회수하는 오염물질 처리기술(cleaning technology)로 대별할 수 있다. 저오염 생산기술은 자동차의 전착공정 등에서 보듯이 오염물질을 최소한도로 배출하게 설계한 'zero discharge' 개념의 생산공정 등에서 실용화되고 있는데, 최근에는 에너지 효율을 향상시켜 궁극적으로 CO$_{2}$의 발생을 억제하려는 시도도 많은 관심을 끌고 있다. 하지만 환경기술이라고 부르는 경우 거의 대부분은 생성된 오염 물질을 처리하는 오염물질 처리기술을 의미한다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.3
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• pp.685-693
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• 1990

The heat transfer coefficients were calculated numerically to see the effects of radiation around the porous medium put on the flat plate at a distance from the leading edge of flat plate for the two-dimensional laminar flows. To verify the analytical model developed and invoke the heat/mass transfer analogy, an experiment was carried out using naphthalene sublimation technique. From the effects of the wake, Sherwood number is maximum around the region where the porous medium is attached. The theoretical results correspond well with the experimental results at small Darcy number. Permeability of ceramic blocks used for experiment was also measured and the Forchheimer equation is applicable in our measurement range.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.139-147
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• 2021

Livestock manure is used as an organic fertilizer to replace chemical fertilizers after sufficient fermentation in an aerobic bioreactor. On the other hand, liquid manure disposal problems occur repeatedly because soil spraying is restricted during the summer when the crops are growing. To use liquid fertilizer (LF) as an additional nutrient source for crops, it is necessary to reduce the amount of suspended solids (SS) in the liquid fertilizer and secure stability problems against pathogenic microorganisms. This study examined the effects of the simultaneous SS removal and E.coli sterilization in the LF using the microbubble (MB) generator (FeMgO catalyst insertion). The remaining SS were further removed using the integrated microbubble and microfilter system. During the floating process in the MB device, the SS were removed by 57.9%, and the coliform group was not detected (16,200→0 MPN/100 mL). By optimizing the HRT of the integrated system, the removal efficiency of the SS was improved by 92.9% under the 0.1h of HRT condition. After checking the properties of the treated LF, 64.5%, 70.1%, 54.9%, and 51.5% of the TCOD, SCOD, PO4-P, and TN, respectively, were removed. The treated effluent from such an integrated system has a lower SS content than that of the existing LF and does not contain coliforms; therefore, it can be used directly as an additional fertilizer.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.582-587
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• 2022

Biphasic solvents are attracting attention as energy-reducing solvents for capturing CO₂ from flue gas in combustion process. In this study, considering diethylenetriamine (DETA) and diethylethanolamine (DEEA) mixed solvents, one of the biphasic solvents by blending of two types of amines, the CO₂ absorption rates of DETA and DEEA was measured by wetted wall column. The effects of DETA and DEEA concentrations and operating temperature on the overall mass transfer coefficient were investigated. As a result, the overall mass transfer coefficient was proportional to the DETA concentration. However, in the case of the DEEA concentration, the effect was small and when the concentration was exceeded, the overall mass transfer coefficient decreased. The DETA aqueous solution showed little change in the overall mass transfer coefficient with the operating temperature, whereas the DEEA aqueous solution increased the overall mass transfer coefficient with the operating temperature. As a result of obtaining the observed reaction rate constant under the pseudo-first-order reaction assumption, it was found that the observed reaction rate constant in DETA aqueous solution was proportional to the DETA concentration, but DEEA did not fit the pseudo-first-order reaction assumption.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.471-471
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• 2012

유기발광소자는 낮은 동작전압, 낮은 전력소비와 높은 색 순도의 장점을 가지고 있어 차세대 디스플레이로 관심을 받고 있다. 시장을 주도하고 있다. 최근 스마트폰의 사용증가에 따른 저전력과 색 표현력에 대한 연구가 필요하며, 발광 효율과 색 순도를 증가하기 위하여 형광 또는 인광 발광 호스트 물질을 사용한 유기발광소자에 대한 연구가 진행되고 있다. 하지만 적색 및 녹색 유기발광소자보다 청색 유기발광소자는 상대적으로 발광 효율과 색순도가 낮기 때문에 청색 유기발광소자를 사용하여 전색 디스플레이를 구현하는데 문제점이 있다. 본 연구에서는 청색 유기발광소자의 색순도와 발광효율을 향상시키기 위하여 형광호스트물질과 인광호스트물질을 혼합하여 구성된 발광층을 가진 청색 유기발광소자에 대한 연구를 하였다. 1,3-bis(carbazole-9-yl)benzene (mCP)에 3-tert-butyl-9,10-di(naphth-2-yl)anthracene (TBADN)을 다양한 혼합비율로 구성한 발광층을 가진 청색 유기발광소자를 제작하여 광학적 성질과 전기적 성질을 관찰하였다. 형광호스트물질과 인광호스트물질의 혼합된 발광층을 적용한 청색 유기발광소자에서 엑시톤의 에너지이동이 원활해지고, 안정된 전자와 정공의 균형으로 인해 동작전압이 감소하고 발광 효율이 증가한다. 위 연구 결과는 낮은 동작전압과 높은 발광효율 갖는 형광물질과 인광물질의 혼합된 발광층 구조를 사용한 청색 유기발광소자를 전색디스플레이에 응용할 경우에 저전압 고효율 전색 발광소자의 제작에 관한 연구에 기여한다.

• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.215-225
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• 2015

Recently, the importance of energy saving and alternative energy is significantly increasing due to energy depletion and the phase change material (PCM) research for saving energy is also actively investigating. In this research, the membrane emulsification using SPG membrane was used to make various microencapsulated phase change material (MPCM) particles which were comprised of $Rubitherms^{(R)}$ (RT-21 and RT-24) core and silica coating. We investigated the pressure of the dispersion phase, the concentration of surfactant, and the ratio of $Rubitherm^{(R)}$ and silica to prepare various MPCM particles. The DSC and TGA were used to examine the heat stability and latent heat properties. Also, PSA, SEM, and optical microscopy were used to confirm the size of $Rubitherm^{(R)}$ particles and the thickness of silica shell. The average of particle size was $7-8{\mu}m$. And, FT-IR was also used to enforce the qualitative analysis. Finally, the MPCM particles obtained from membrane emulsification showed monodispersed size distribution and the heat stability and latent heat were kept up to 80% compared to pure $Rubitherm^{(R)}$. So, it can be effectively used for wallpaper, buildings and interior products for energy saving as PCMs.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.233-238
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• 2008

Korea has a high volume of exhaust in environmental pollutants compared to her economic size, which results from the increase of the ratio in high energy consuming industries. There arises an issue that efficient energy saving is not achieved in the related projects of the construction, which is one of the high energy consuming industries. In addition, such projects of dismantling old and decrepit buildings are frequent in recent years. Given the situation, to obtain much better effects of energy saving, it is necessary to build basic databases and develop utilization plans on energy consumption volume, exhaust volume of pollutants, and environmental expenses that come from the dismantlement stages out of the life cycle of construction projects. Therefore, this study calculates the exhaust volume of environmental pollutants, converts it into environmental expenses by pollutants, and evaluates the environmental economics on the projects of dismantling buildings, utilizing LCI DB that is suggested by Ministry of Knowledge Economy and Ministry of Environment. For this purpose, related data research, the existing literature study, and on-the-spot field investigation were conducted. Based on the results of analysis on the collected data, the environmental economics of the target building was evaluated.