• Journal of Korean Society for Atmospheric Environment
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• 제23권E2호
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• pp.39-46
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• 2007

In order to present the scientific information of organic emissions from consumer products available, the current study examined the emissions composition for three different types of consumer products being used in Korea in an environmental chamber: air freshener (AF), mosquito repellents (MSQR), and moth repellents (MTHR). Emission rates were evaluated by determining emission rates of the target compound from the selected products using an electropolished stainless steel (SS) test chamber $(40{\times}25{\times}50cm^3)$. A time-dependent empirical relationship developed in this study agreed well with the test results. As same with the emission concentrations, MSQR exhibited the highest emission rate for all target compounds except for limonene and naphthalene. MTHR ($9,200\;{\mu}g\;h^{-1}$) showed the highest emission rate of naphthalene followed by MSQR ($8,300\;{\mu}g\;h^{-1}$). Moreover, the concentrations in residential bedroom conditions for target compounds emitted from three types of consumer products were estimated. This estimation suggests that the uses of consumer products can elevate indoor levels of target compounds. In particular, any types of the consumer products may increase the indoor level of m, p-xylene.

• Environmental Engineering Research
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• 제18권3호
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• pp.145-150
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• 2013

Optimal preparation guidelines of a cathode catalyst layer by non-precious metal catalysts were evaluated based on electrochemical performance in single-chamber microbial fuel cells (MFCs). Experiments for catalyst loading rate revealed that iron(II) phthalocyanine (FePc) can be a promising alternative, comparable to platinum (Pt) and cobalt tetramethoxyphenylporphyrin (CoTMPP), including effects of substrate concentration. Results showed that using an optimal FePc loading of $1mg/cm^2$ was equivalent to a Pt loading of $0.35mg/cm^2$ on the basis of maximum power density. Given higher loading rates or substrate concentrations, FePc proved to be a better alternative for Pt than CoTMPP. Under the optimal loading rate, it was further revealed that 40 wt% of FePc to carbon support allowed for the best power generation. These results suggest that proper control of the non-precious metal catalyst layer and substrate concentration are highly interrelated, and reveal how those combinations promote the economic power generation of single-chamber MFCs.

• Environmental Engineering Research
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• 제24권3호
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• pp.443-448
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• 2019

The present study was conducted to compare the voltage generation in two-chamber microbial fuel cells (MFCs) with a biocathode where nitrate and oxygen are used as a terminal electron acceptors (TEA) and to investigate the nitrogen removal and the electrochemical characteristics depending on the separators of the MFCs for denitrification. The maximum power density in a biocathode MFC using an anion exchange membrane (AEM) was approximately 40% lower with the use of nitrate as a TEA than when using oxygen. The MFC for denitrification using an AEM allows acetate ($CH_3COO^-$) as a substrate and nitrate ($NO_3{^-}$) as a TEA to be transported to the opposite sides of the chamber through the AEM. Therefore, heterotrophic denitrification and electrochemical denitrification occurred simultaneously at the anode and the cathode, resulting in a higher COD and nitrate removal rate and a lower maximum power density. The MFC for the denitrification using a cation exchange membrane (CEM) does not allow the transport of acetate and nitrate. Therefore, as oxidation of organics and electrochemical denitrification occurred at the anode and at the cathode, respectively, the MFC using a CEM showed a higher coulomb efficiency, a lower COD and nitrate removal rate in comparison with the MFC using an AEM.

• 한국환경보건학회지
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• 제30권5호
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• pp.487-492
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• 2004

Building materials are composed of very complex chemical compounds, and these indoor building materials discharge very much Volatile Organic Compounds(VOCs). We performed the environmental chamber test to investigate the Total VOCs(TVOCs) emission characteristics and emission factors about chemical and natural coating materials. As the result, we concluded that TVOCs emission are high at initial time and decreased in course of time. Natural paint was low emission level for TVOCs than chemical paint by small chamber test. The TVOCs emission factor-time profile showed a good fit with the results from the measured and predicted value.

• 대한환경공학회지
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• 제38권10호
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• pp.535-542
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• 2016

플럭스 챔버법은 비용효율적인 표면 발산량의 측정방법으로 다양한 연구 분야에 널리 이용되어 왔다. 플럭스 챔버법은 운용 방식에 따라 기울기 방식을 이용한 닫힌 챔버법(SFC)과 평형 농도 방식을 이용한 열린 챔버법(DFC)으로 분류할 수 있는데, SFC 방식은 장비가 간단하고 운용이 쉬운 반면, 직선성에 대한 불확실한 가정으로 인하여 플럭스 산정 값이 가변적인 단점이 있다. 한편, DFC 방식은 더 많은 특정 기기가 필요하지만, 어떤 애매모호함이 없이 일정한 값을 산정할 수 있다. 따라서 본 연구는 작고 조밀한 키트를 이용하여 DFC를 자체 제작하였다. 자체 제작한 DFC는 30분 이내에 평형상태에 도달하였고, 측정 초기의 불충분한 혼합을 제외하면 시료 균질도가 5% 미만이고, 회수율이 90% 이상으로 우수하였다. 이 개선된 DFC의 상대확장불확도는 7.37%로 평가되었는데, 이는 주로 통제되지 않은 유입가스에 기인한다. 연구 결과는 대규모 매립지에서 소형의 측정 키트를 이용한, 개선된 DFC 방식이 신뢰성이 높은 자료를 효과적으로 축적할 수 있음을 보여준다.

• 한국농림기상학회지
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• 제7권1호
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• pp.107-114
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• 2005

토양 호흡은 주요 육상 생태계의 탄소 순환을 이해하는데 중요한 성분 중 하나이다. 토양 호흡 관측에서 쳄버 방법은 가장 일반적인 방법이다. 다양한 토양 호흡쳄버 방법에 의해 이루어지는 관측 값들을 비교하기 위해서는, 측기의 특성에 따른 오차를 파악하는 것이 필요하다. 이를 위하여 온도 조절이 가능한 식물 환경 조절 시스템에서 네 개의 폐회로 역학 쳄버와 자동 개폐 쳄버를 비교하였다. 식물 환경 조절 시스템의 내부의 이산화탄소 농도의 변동과 토양 수분의 변동으로 어느 정도의 오차가 포함된 결과이지만, 실험을 통해 토양 온도와 이산화탄소 농도의 변화에 따른 대한 네 측기들의 반응 특성과 실내 비교 실험의 계획과 방법에 대한 중요한 교훈을 얻을 수 있었다.

• Journal of the Korean Wood Science and Technology
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• 제36권2호
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• pp.46-55
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• 2008

This study assesses the formaldehyde and TVOC emissions from bio-composites with attached fancy veneer manufactured using wood flour and polypropylene (PP) measured using the Field and Laboratory Emission Cell (FLEC) method and 20 L small chamber method. To determine and compare the effects of the adhesive, samples were prepared with different manufacturing methods. In the FLEC result, the formaldehyde emission level of the bio-composites with attached veneer by hot-press was the lowest than pure bio-composite and bio-composite attached veneer using adhesive. The TVOC emission levels are similar to the formaldehyde emission. The TVOC emission level is very low in all of the samples except fancy veneer that is attached with bio-composites using adhesive. The TVOC emission varies depending on how attaching fancy veneer. The results of the 20 L small chamber method were very similar to those obtained with the FLEC, but the correlation was not perfect. However, the FLEC method requires a shorter time than the 20 L small chamber method to measure the formaldehyde and TVOC emissions. The internal bonding strength exceeded the minimum value of $0.4N/mm^2$ specified by the KS standard. All of the bio-composites with attached veneer satisfied the KS standard.

• Journal of Preventive Medicine and Public Health
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• 제5권1호
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• pp.9-15
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• 1972

Carbon monoxide poisoning is one of the most serious health problems in Korea, because we have been encountered with the highest incidence of CO poisoning in the world due to the unique heating system in home called 'ondal'. We opened Hyperbaric chamber unit in the Seoul National University Hospital last Jan, 1969. We have treated 848 patients as of Sept. 30., 1972, around 44 months period. We collected the informations on the environmental conditions of the place where CO intoxication actually occured by filling up the questionaire from 505 patients. The following findings were obtained. 1. Age distribution showed that the highest incidence was found in the younger age group between age of 10 to age of 29 in both sex. 2. Sex ratio of the patients was 1:1.14. 3. The socio-economic level of the patient was relatively low. 4. Housewife & housemaid were the major victims of the intoxication in the female patients & in the case of the male patient, occupational backgrounds were diverse. 5. Many patients from the middle class experienced the intoxication by sleeping at newly built room. 6. Many intoxication has been occured in the structure of houses where communicating doors are existing between living room & kitchen. 7. All findings obtained taught us again that CO poisoning is the serious by-product of the national fuel policy which put emphasis on the use of coal & socio-economic status is a very important parameter in this hazards.

• 한국입자에어로졸학회지
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• 제12권3호
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• pp.57-63
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• 2016

The laser-induced breakdown spectroscopy (LIBS) has been used for rapid detection of elemental compositions of various materials in multi-media (solid, liquid, gas, and aerosols). In this study, the aerosol-LIBS has been developed for real-time monitoring of process-induced particles produced during the semiconductor manufacturing. The developed aerosol-LIBS mainly consists of laser, optics, spectrometer, and aerosol chamber. A new aerosol chamber was constructed for the aerosol-LIBS to be applied for various semiconductor manufacturing process, including exhaust tubes, and low pressure and high temperature chamber. The aerosol-LIBS was evaluated by using laboratory generated aerosols for detection of various elements. As a result, P, Fe, Mg, Cu, Co, Ni, Ca, Na, and K emission lines were successfully detected by the aerosol-LIBS. Further evaluation of the aerosol-LIBS is being conducted.

• 분석과학
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• 제24권4호
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• pp.290-297
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• 2011

현재 자동차 실내공기질을 평가하는 방법이 ISO, 중국, 일본에서 개발 중에 있으며, 우리나라에서도 관리기준이 2010년 7월 1일 이후 생산한 신규제작자동차부터 적용되고 있다. 자동차 실내공기질을 관리하기 위해서는 자동차 실내의 내장부품으로부터 방출되는 휘발성 유기화합물을 평가하는 것이 중요하다. 이 연구에서는 모듈단위부품인 도어트림 모듈의 구성부품인 도어트림 암레스트를 ISO 12219-5방법에 따라 완제품을 평가 하였으며, ISO 12219-3방법으로 절단부품과 도어트림 구성소재를 평가하였다. Tenax TA가 충진된 스테인리스 튜브를 이용하여 VOC를 채취하여 TD-GC/MS를 이용하여 분석하였다. 두 시험방법을 비교한 결과 도어트림 암레스트로부터 방출되는 물질의 비율이 차이가 있음을 확인하였고, 도어트림 암레스트의 소재를 평가한 결과 PP substrate과 adhesive가 도어트림 암레스트에서 주요 방출원인 소재로 나타났다.