• Product Safety
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• s.198
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• pp.62-65
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• 2010

생활수준이 향상됨에 따라 에어컨은 이제 생활 필수품이 되었다. 단순히 온도를 조절하는 데서 나아가 최근에는 기류제어 공기청정 탈취 살균 제균 등 다양한 부가기능을 갖추고 있다. 이렇게 편리한 에어컨을 안전하게 사용하려면 적절한 설치 및 사용관리 방법을 잘 알아야 한다.

• Journal of the KSME
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• v.32 no.3
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• pp.290-299
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• 1992

대기질의 악화와 오염원이 많아짐에 따라, 실내공기 정화장치 또한 재래식의 방법을 벗어난 방 식으로 설계 시설되어야 한다. 인위적으로 만들어진 유해 물질과 작은 먼지들을 제거하기 위한 새로운 환풍장치는 지역의 특수성을 고려하여 설계되어야 한다. 더욱이 대도시의 생활은 오염 원과 작업장 및 거주지가 가까이 위치하기 때문에 특별히 지역의 특수성을 고려하여 환풍장치가 설계되어야 한다. 끝으로 작업장안에서 오염원 격리수용하는 것은 매우 바람직하여, 청정공 간(clean room)을 요구하는 반도체 및 제약회사 등은 건축물자체 오염원에서 멀리 떨어져서 지 역의 영향을 최소화하는 것과 건축물의 자재 및 공기정화장치가 새롭게 연구되어 설계되야 한다.

• Korean Chemical Engineering Research
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• v.48 no.3
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• pp.311-315
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• 2010

The effects of $SO_2$ on the performance of proton exchange membrane(PEMFC) were investigated by introduction air containing $SO_2$ into cathode inlet of PEMFC. And the recovery of the cell performance by applying clean air, cycle voltammetry(CV) and high voltage holding following exposure contaminated air was studied. The $SO_2$ concentration range used in the experiments was from 20 ppb to 1.3 ppm. The performance degradation and recovery were measured by constant-current discharging, I-V polarization and electrochemical impedance spectroscopy(EIS). The cell voltage gradually decayed with time and decreased by 17 mV after 200 hours of 20 ppb $SO_2$ injection. The cell performance can be recovered partially by clean air flushing, CV and high voltage holding due to desorption of S from Pt catalyst.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.348-349
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• 2001

휘발성유기화합물 (VOCs)은 복잡 다양한 발생원에서 배출되고 있다. 1990년에 개정된 미국 공기청정법 (US Clean Air Act Amendments, CAAA)에서는 총 189개의 화합물을 인간환경에 유해한 유해 대기 오염물질 (HAP, hazordous air pollutants)로 분류하고 있다 (MacKensie, A.R 등, 1991). 이 중 미국 EPA에서는 유해 대기오염물질로서 43개의 VOCs를 정하여, TO-14 화합물로서 일컫고 있다 (허귀석, 1999). (중략)

• Clean Technology
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• v.4 no.2
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• pp.32-40
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• 1998

The polymeric porous materials which consist of polypropylene(PP) and polyethylene(PE) powder were prepared to apply to the air purification systems by extrusion sintering method. SEM analysis showed that a composite polymeric porous structure made up of PP and PE was obtained, where PE was melted and adhered to PP because the melting temperature of PE was lower than that of PP. The filtration characteristics and mechanical properties of polymeric porous materials were investigated by varying the head die temperature of the extruder, extrusion velocity, and the melt index and quantity of PE. The filtration efficiency was proportional to the quantity of PE but inversely proportional to the melt index of PE. The polymeric porous materials composed of PP and PE, which was made by extrusion sintering method, was found to be suitable for the filter element of the air purification system.

• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.15-20
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• 2011

The contamination effect of toluene in the airstream on PEM fuel cell performance was studied with various toluene concentration under different operation conditions. And the recovery of the cell performance by applying clean air and the removal of toluene in the air by adsorption of active carbon were investigated. The toluene concentration range used in the experiments was from 0.1 ppm to 5.0 ppm. The performance degradation and recovery were measured by constant-current discharging and electrochemical impedance spectroscopy(EIS). Toluene adsorption capacity of KOH impregnated active carbon was obtained from the adsorption isotherm curve. The severity of the contamination increased with increasing toluene concentration, current density and air stoichiometry, but decrease with increasing relative humidity. The cell performance was recovered by toluene oxidation with oxygen and water in humidified neat air. EIS showed that the increase of charge transfer resistance due to toluene adsorption on Pt surface mainly reduced the performance of PEMFC. Toluene adsorption capacity of active carbon decreased as KOH weight increased in KOH impregnated active carbon.

• Clean Technology
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• v.15 no.2
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• pp.75-80
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• 2009

In order to separate oxygen from air, the effects of feed gas flow rate and rinse gas flow rate on the product purity and flow were examined using 2 bed PSA with 4 step cycle. The addition of product pressurization step increased the product purity and flow rate. The addition of pressure equalization increased the product flow rate. The test product was manufactured and the purity and flow rate of product oxygen was examined. The results were compared with the commercial medical oxygen generator of 5 ${\ell}/min$ and 90% oxygen purity.

• Clean Technology
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• v.28 no.1
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• pp.18-23
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• 2022

Using air as an insulator due to its low heat transfer coefficient has been studied and has been widely commercialized to save energy in the field of thermal insulation technology. In this study, we analyzed the heat insulating effect of hollow silica nanoparticles mixed in non-uniform size, and the maximum heat insulating efficiency of these particles given the limited number of particles that can be mixed with a medium such as paint. The hollow silica nanoparticles were synthesized via a sol-gel process using a polystyrene template in order to produce an air layer inside of the particles. After synthesis, the particles were analyzed for their insulation effect according to the size of the air layer by adding 5 wt % of the particles to paint and investigating the thermal insulation performance by a heat transfer experiment. When mixing the particles with white paint, the insulation efficiency was 15% or higher. Furthermore, the large particles, which had a large internal air layer, showed a 5% higher insulation performance than the small particles. By observing the difference in the insulation effect according to the internal air layer size of hollow silica nanoparticles, this research suggests that when using hollow particles as a paint additive, the particle size needs to be considered in order to maximize the air layer in the paint.

• Clean Technology
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• v.13 no.1 s.36
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• pp.1-15
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• 2007

Biological treatment is a relatively recent air pollution control technology in which off-gases containing biodegradable odors and volatile organic compounds(VOCs) are vented through microbes. It is a promising alternative to conventional air pollution control methods. Bioreactors for air pollution control have found most of their success in the treatment of dilute and high flow waste air streams containing VOCs and odor compounds. They offer several advantages over traditional technologies such as incineration or adsorption. These include lower treatment costs, absence of formation of secondary pollutants, no spent chemicals, low energy demand and low temperature treatment. The three most widely used technologies are described, namely biofiltration, biotrickling filtration, bioscrubbing. The most widely used bioreactor for air pollution control is biofilter, but it has several limitations. In the past years major progress has been accomplished in the development of vapor phase bioreaction systems, for solving problems of biofilter. Biotrickling filters are more complex than biofilters, but are usually more effective, especially for the treatment of compounds which are difficult to degrade or compounds that generate acidic by-products. This, paper reviews fundamental and theoretical/practical aspect of air pollution control in biofilter, biotrickling filter and bioscrubber, focusing more extensively on biotrickling filtration. Special emphasis is given to the operating parameters and the factors influencing performance for air pollution control, and cost estimation in biotreatment technologies.

• Clean Technology
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• v.23 no.2
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• pp.205-212
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• 2017

We investigated the performance of a jet loop reactor (JLR) with the two-fluid venturi-type swirl nozzle (TVSN) during experiment for ammonia removal by air stripping from a synthetic wastewater, and compared it with that of a JLR with the two-fluid venturi-type conventional nozzle (TVCN), with the variation of pH, liquid circulation rate ($Q_L$), and air flow rate ($Q_G$). Their performance levels were compared based on the ammonia removal efficiency and overall mass transfer coefficient ($K_La$). Investigated parameters in a JLR were pH (10-12), air flow rate ($Q_G=5-20L\;min^{-1}$), and liquid circulation rate ($Q_L=25-35L\;min^{-1}$). Throughout the experiment, the ammonia removal efficiency and $K_La$ in a JLR with TVSN was higher than in a JLR with TVCN. This may be due to the enhanced turbulent intensity by swirling flow formed in the JLR with TVSN compared to that with TVCN. Further, we obtained higher $K_La$ when pH, $Q_L$ and $Q_G$ were increased. In particular, $K_La$ was increased more efficiently by increasing $Q_G$ than by increasing pH and $Q_L$.