산화전리시스템의 전극재질에 따른 정화조 악취제거

남윤기,김진성,송지현 한국대기환경학회 2012 한국대기환경학회 학술대회논문집 Vol.2012 No.5

Surface functionalization approach for Brain-on-a-Chip technology

남윤기 한국고분자학회 2016 한국고분자학회 학술대회 연구논문 초록집 Vol.41 No.1

연구논문 - 고분자공업분과 : 우레탄 전선 도료를 위한 TDI 와 MDI 의 Blocking 반응에 관한 연구

남윤기,박내정,권석기 한국공업화학회 1996 한국공업화학회 연구논문 초록집 Vol.1990 No.3

뉴런온칩 기술: 미세전극칩시스템과 신경세포 패터닝 기술

남윤기,Nam, Yoon-Key 대한의용생체공학회 2009 의공학회지 Vol.30 No.2

Neuron-on-a-Chip technology is based on advanced neuronal culture technique, surface micropatterning, microelectrode array technology, and multi-dimensional data analysis techniques. The combination of these techniques allowed us to design and analyze live biological neural networks in vitro using real neurons. In this review article, two underlying technologies are reviewed: Microelectrode array technology and Neuronal patterning technology. There are new opportunities in the fusion of these technologies to apply them in neurobiology, neuroscience, neural prostheses, and cell-based biosensor areas.

Brain on a Chip 구현을 위한 MEA 기술의 현황과 전망

남윤기,Nam, Yun-Gi 대한전자공학회 2007 전자공학회지 Vol.34 No.9

Neuronal Micro-culture Engineering by Microchannel Devices of Cellular Scale Dimensions

남윤기,Gaurav Goyal 대한의용생체공학회 2011 Biomedical Engineering Letters (BMEL) Vol.1 No.2

Purpose The purpose of the current study was to investigate the effect of microchannel geometry on neuronal cultures and to maintain these cultures for long period of time (over several weeks) inside the closed microchannels of cellular scale dimensions. Methods The primary hippocampal neurons from E-18 rat were cultured inside the closed polydimethylsiloxane (PDMS)microchannels of varying sizes. The effect of the channel geometry on the spatial and the temporal variations in the neural microenvironment was investigated by studying neural maturation and variation in the media osmolality respectively. The cultures were maintained for longer time spans by PDMS device pretreatment, control on media evaporation (by using hydrophobic ethylene propylene membrane) and an effective culture maintenance protocol. Further, the devices were integrated with the planar microelectrode arrays (MEA)to record spontaneous electrical activity. Results A direct influence of channel geometry on neuron maturation was observed with cells in smaller channels maturing faster. The temporal variation in the microenvironment was caused by several fold increase in osmolality within 2-3 days due to rapid media evaporation. With our culture methodology,neurons were maintained in the closed channels as small as 50 μm in height and width for over 1 month in serum free media condition and the time varying spontaneous electrical activity was measured for up to 5 weeks using the MEA. Conclusions The understanding of the effect of the culture scale on cellular microenvironment and such long-term culture maintenance will be helpful in studying neuronal tissue development; therapeutic drug screening; and for network level neuronal analysis.

황계열 악취물질 제어를 위한 저온플라즈마와 촉매산화제 적용에서 상대습도의 영향

남윤기,송지현,안해영 한국냄새환경학회 2013 실내환경 및 냄새 학회지 Vol.12 No.4

In year 2010, the foot-and-mouth disease spreaded all over the country in Korea, and approximately 3,000,000 animals were killed and more than 4,800 carcass burial sites were urgently made. Inside the carcass burial sites, sulfur-containing odor compounds such as hydrogen sulfide and dimethyldisulfide (DMDS) were produced by anaerobic microorganisms. In this study, a non-thermal plasma (NTP) system was applied for the removals of sulfur compounds emitted from carcass decomposition. Especially, the effects of relative humidity on the hydrogen sulfide and DMDS removals in the NTP reaction was evaluated. When relative humidity increased from <5% to 90% in the inlet odor-containing gas stream, the amount of ozone produced also increased, so that the hydrogen sulfide and DMDS removal efficiency increased as well. Based on the Gibb’s free energy calculations for the ozone reactions with hydrogen sulfide and DMDS, the oxidation potential of DMDS with ozone was much stronger than that of hydrogen sulfide; therefore, DMDS was first removed by ozone, and hydrogen sulfide was further oxidized in the following catalyst bed. 2010년 전국적으로 소, 돼지와 같은 동물에 구제역이 발병하였고, 이에 전국에 약 4,800여개의 매몰지가 긴급 조성되고 약 300만 마리의 동물들을 살처분 되었다. 이렇게 조성된 매몰지 내부에서는 가축사체가 부패하는 과정에서 황화수소, 메르캅탄류, 아민류와 같은 악취물질이 생성되고, 매몰지 이설과정에서 대기 중으로 확산된다. 본 연구에서는 가축 매몰지 이설과정 중에 발생하는 황 계열 물질을 저온 플라즈마 시스템을 적용하여 저감하고자 하였다. 특히 플라즈마 시스템에서 상대습도에 따른 황화수소와 다이메틸다이설파이드(DMDS) 제거량 변화를 실험적으로 확인하였다. 동일한 유입 조건에서 상대습도가 증가함에 따라 황화수소와 DMDS의 제거율은 증가하였고, 이는 상대습도가 높아지면서 발생하는 오존량이 증가하였기 때문이었다. 황화수소와 DMDS의 오존 반응식을 깁스 자유에너지로 비교해보면 DMDS의 오존 산화가 더 높은 에너지를 방출하는 것으로 나타나며, 이에 따라 황화수소보다는 DMDS가 먼저 오존에 의해 산화되며 남은 황화수소는 촉매 층에서 추가 반응하는 것으로 판단된다.

황계열 악취물질 제어를 위한 저온플라즈마와 촉매산화제 적용에서 상대습도의 영향

남윤기,안해영,송지현 한국냄새환경학회 2013 실내환경 및 냄새 학회지 Vol.12 No.4

2010년 전국적으로 소, 돼지와 같은 동물에 구제역이 발병하였고, 이에 전국에 약 4,800여개의 매몰지가 긴급 조성되고 약 300만 마리의 동물들을 살처분 되었다. 이렇게 조성된 매몰지 내부에서는 가축사체가 부패하는 과정에서 황화수소, 메르캅탄류, 아민류 와 같은 악취물질이 생성되고, 매몰지 이설과정에서 대기 중으로 확산된다. 본 연구에서 는 가축 매몰지 이설과정 중에 발생하는 황 계열 물질을 저온 플라즈마 시스템을 적용하 여 저감하고자 하였다. 특히 플라즈마 시스템에서 상대습도에 따른 황화수소와 다이메틸 다이설파이드(DMDS) 제거량 변화를 실험적으로 확인하였다. 동일한 유입 조건에서 상대 습도가 증가함에 따라 황화수소와 DMDS의 제거율은 증가하였고, 이는 상대습도가 높아 지면서 발생하는 오존량이 증가하였기 때문이었다. 황화수소와 DMDS의 오존 반응식을 깁스 자유에너지로 비교해보면 DMDS의 오존 산화가 더 높은 에너지를 방출하는 것으로 나타나며, 이에 따라 황화수소보다는 DMDS가 먼저 오존에 의해 산화되며 남은 황화수 소는 촉매 층에서 추가 반응하는 것으로 판단된다. In year 2010, the foot-and-mouth disease spreaded all over the country in Korea, and approximately 3,000,000 animals were killed and more than 4,800 carcass burial sites were urgently made. Inside the carcass burial sites, sulfur-containing odor compounds such as hydrogen sulfide and dimethyldisulfide (DMDS) were produced by anaerobic microorganisms. In this study, a non-thermal plasma (NTP) system was applied for the removals of sulfur compounds emitted from carcass decomposition. Especially, the effects of relative humidity on the hydrogen sulfide and DMDS removals in the NTP reaction was evaluated. When relative humidity increased from <5% to 90% in the inlet odor-containing gas stream, the amount of ozone produced also increased, so that the hydrogen sulfide and DMDS removal efficiency increased as well. Based on the Gibb’s free energy calculations for the ozone reactions with hydrogen sulfide and DMDS, the oxidation potential of DMDS with ozone was much stronger than that of hydrogen sulfide; therefore, DMDS was first removed by ozone, and hydrogen sulfide was further oxidized in the following catalyst bed

고농도 유기성 퇴적물에서 발생하는 황계열 악취물질 제거를 위한 전기산화시스템의 적용

김진성,남윤기,송지현 한국냄새환경학회 2013 실내환경 및 냄새 학회지 Vol.12 No.4

도시지역 합류식 하수배제 설비인 우수받이 및 하수관거, 정화조 등에는 유기성 고형 물이 퇴적되기 쉬우며, 유기성 퇴적물이 부패되는 과정에서 고농도의 황계열 악취물질이 발생한다. 본 연구에서는 전기산화방식을 이용하여 유기성 퇴적물 내에 용존된 악취물질 및 전구물질을 저감시켜, 하수관거에서 기상으로 배출되는 악취 문제를 해결하고자 하였다. 실험실 규모의 밀폐된 회분식 반응기에 하수슬러지(COD 기준 8,000 ~ 28,000 mg·L-1)를 투입하고, 발생되는 악취물질 농도와 악취발생특성을 조사하였다. 여기에 전기산화시스템 을 적용하여 황계열 악취물질과 전체 유기물의 산화 및 분해실험을 진행하였다. 전기산 화 실험을 진행한 결과, 밀폐된 반응기의 기상에서 450 ppm의 고농도로 발생한 황화수 소가 반응 30분 이내에 검출한계 이하까지 제거되었으며, 메틸머켑탄과 디메틸설파이드 는 85% 이상 제거되었다. 투입된 전기에너지당 황계열 악취물질의 제거율은 최대 0.33 mg-S·kJ-1로 나타났다. 또한 1시간의 반응기간 동안 회분식 반응기 내에서 황계열 악취물 질 뿐만 아니라 고농도 퇴적물에 함유된 전체 유기물 농도가 56% 감소하여, 전기산화시 스템이 악취를 유발하는 유기성 전구물질을 동시에 저감하는 효과를 나타내었다. 결과적 으로 최소한의 전기에너지를 이용하여 하수관거 퇴적 유기물에 의한 악취문제를 해결할 수 있을 것으로 기대된다 Organic solids, deposited at the bottom of the domestic wastewater discharge pipelines, cause odor problems because high strength sulfur-containing odorous compounds are produced during the anaerobic degradation of the organic sediments. In this study, an electrolytic oxidation (EO) system was applied to reduce soluble odorous compounds in the organic sediments and to minimize the odor problems from the wastewater discharge facilities. Wastewater sludge in a range of COD 8,000 – 28,000 mg·L-1 was added into a lab-scale closed-container, and emission characteristics of sulfur-containing compounds were monitored. When the EO system was applied, the concentration of hydrogen sulfide in the head space was rapidly dropped from 450 ppm to under the detection limit within 30 minutes of operation. The maximum removal of the sulfur compounds per input energy was found to be 0.33 mg-S·kJ-1·L-1. In addition, organic constituents in the sediment were degraded along with amounts of the odorous compounds by the EO system, showing 56% reduction of COD within one hour operational period. Consequently, the EO system using low electrical energy can be effectively applied to abate the odor problems from the wastewater discharge facilities.

습식 플라즈마의 기체체류시간과 액기비에 따른 황화수소 및 부유미생물 동시제거

김진성,남윤기,안해영,송지현 한국냄새환경학회 2015 실내환경 및 냄새 학회지 Vol.14 No.1

Odor compounds and air-born microorganisms are simultaneously emitted from various aeration processes such as aerobic digestion, food-waste compositing, and carcass decomposition facilities that are biologically-treating wastes with high organic contents. The air streams emitted from these processes commonly contain sulfur-containing odorous compounds such as hydrogen sulfide(H2S) and bacterial bioaerosols. In this study, a wet-plasma method was applied to remove these air-born pollutants and to minimize safety issues. In addition, the effects of a gas retention time and a liquid-gas ratio were evaluated on removal efficiencies in the wet-plasma system. At the gas reaction time of 1.8 seconds and the liquid-gas ratio of 0.05 mLaq/Lg, the removal efficiency of bioaerosol was approximately 75 %, while the removal efficiency of H2S was lower than 20 %, indicating that the gaseous compound was not effectively oxidized by the plasma reaction at the low liquid addition. When the liquid-gas ratio was increased to 0.25 mLaq/Lg, the removal efficiencies of both H2S and bioaerosol increased to greater than 99 %. At the higher liquid-gas ratio, more ozone was generated by the wet-plasma reaction. The ozone generation was significantly affected by the input electrical energy, and it needed to be removed before discharged from the process.