Development of novel on-line capillary gas chromatography-based analysis method for volatile organic compounds produced by aerobic fermentation

Lee, Hyeok-Won,Park, Jung-Ho,Lee, Hee-Suk,Kim, Chun-Suk,Lee, Jin-Gyeom,Kim, Won-kyo,Ryu, Kyoung-Hwa,Ahn, Jung-Oh,Lee, Eun-Gyo,Kim, Seon-Won,Jeon, Jong-Min,Yang, Yung-Hun,Choi, Eui-Sung,Lee, Hong-Weon Society for Bioscience and Bioengineering, Japan 2019 Journal of bioscience and bioengineering Vol. No.

<P>Many volatile compounds, such as isoprene, a precursor used in the synthesis of natural rubber, have been produced through fermentation using genetically engineered microorganisms. Despite this biotechnological success, measuring the concentrations of volatile compounds during fermentation is difficult because of their high volatility. In current systems, off-line analytical methods usually lead to product loss, whereas on-line methods raise the production cost due to the requirement of complex devices. Here, we developed a novel on-line gas chromatography (GC)-based system for analyzing the concentration of isoprene with the aim to minimize the cost and requirement for devices as compared to current strategies. In this system, a programmable logic controller is used to combine conventional GC with a syringe pump module (SPM) directly connected to the exhaust pipe of the fermentor, and isoprene-containing samples are continuously pumped from the SPM into the GC using an air cylinder recycle stream. We showed that this novel system enables isoprene analysis during fermentation with convenient equipment and without the requirement of an expensive desorption tube. Furthermore, this system may be extended to the detection of other volatile organic compounds in fermentation or chemical processes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This system analyzes the concentration of isoprene in aerobic fermentation. </LI> <LI> PLC is used to combine conventional GC with SPM directly connected to fermenter. </LI> <LI> Produced isoprene is continuously analyzed using the GC. </LI> <LI> This system may be extended to the detection of other volatile organic compounds. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

히트싱크 재료 특성에 따른 방열 성능에 대한 연구

송의혁 ( Eui-hyeok Song ),( Riguang Chi ),유대겸 ( Dae-gyeom Yu ),이석호 ( Seok-ho Rhi ),이동주 ( Dong-ju Lee ),이계복 ( Kye-bock Lee ) 충북대학교 산업과학기술연구소 2019 산업과학기술연구 논문집 Vol.33 No.1

Power electronics devices are now widely used to efficiently deliver electrical power in hybrid/electric cars, home electronics, telecommunication, and so on. Large heat accompanied with these power electronics should be transmitted to the heat sink. In the present study, cooling technologies based on heat sink with different material and thermal properties. High cooling performance can manage junction temperatures to achieve goals for system efficiency, product cost, and system reliability. Cooling technologies depend on heat spreading and moving by heat conduction associated with convection. Usually, natural or forced air cooling heat sink provides efficient heat spreading. Thermal stress of electronics PCB is affected by thermal expansion in interconnection with different material. In the present study, pin fin heat sinks of different materials were investigated in terms of 3 dimensional thermal conductivity allocation. In this analysis, the cooling performance was observed in three terms of chip junction temperature variation. heat sinks made of usual metallic materials such as Copper and Aluminum were compared with heat sinks of orthographic thermal conductivity composite materials. The pin-fin heat sink of k_x-k_y-k_z = 810-52-810 W/m-K composite material shows slightly higher thermal performance. The optimum heat sink design should be accompanied with special care on thermal conductivity allocation in three dimensional directions.

원격탐사와 수재해 정보 플랫폼을 이용한 홍수 가뭄 모니터링 시스템 개발

Jin Gyeom Kim,Yong Hyeon Lee,Wan Sik Yu,Eui Ho Hwang 위기관리 이론과 실천 2021 Crisisonomy Vol.17 No.6

지난 10년간 우리나라에서 발생한 자연재해의 88%는 호우와 태풍에 의해 발생했으며 정량적 피해를 산출하기 어려운 가뭄피해 또한 광역적으로 발생하고 있다. 본 연구에서는 한반도를 포함한 동아시아 지역에 홍수, 가뭄 등의 수재해 정보를 모니터링하고 예측하기 위한 수재해 정보 플랫폼과홍수/가뭄 모니터링 시스템을 개발하였다. 수재해 정보 플랫폼은 인공위성, 레이더, 지상관측 자료를활용하여 홍수와 가뭄 등의 수해재를 모니터링 할 수 있는 시스템을 갖추고 있다. 본 폴랫폼에는피해규모가 상대적으로 큰 도시지역을 대상으로 고해상도 레이더 기반 홍수 모니터링 시스템이 운영되고 있으며 위성기반의 임진강 접경지역의 홍수 모니터링 시스템과 한반도를 포함한 광역적 가뭄 감시 및 예측 시스템이 운영되고 있다. 수재해 정보 플랫폼의 홍수/가뭄 모니터링 시스템을 통해국민의 생명과 재산을 보호하고 홍수, 가뭄 등 수재해의 선제적 대응이 가능한 해결책이 되길 기대한다. 88% of the natural disasters in South Korea over the past ten years were caused by heavy rains and typhoons. In addition, drought damage, which is challenging to estimate quantitative damage, occurs in a wide area. In this study, a water hazard information platform was developed to monitor and predict water hazard information such as drought and flood in a wide area of East Asia, including the Korean Peninsula. The water hazard information platform is equipped with a system that can monitor water disasters such as drought and floods by using satellite, radar, automatic weather station data. This platform has an X-band radar system for predicting and monitoring urban floods with a significant damage scale. The Imjin River flood prediction system in the border area is operating for flood monitoring. The drought monitoring and forecasting system is operating using satellite-based in a wide area. Through the water hazard information platform, it is expected to protect the lives and property of the people and as a critical solution for a preemptive response to water hazards such as floods and droughts.

부유식 태양광 발전기의 패널과 부유체에 작용하는 풍하중과 유동특성

유대겸(Dae Gyeom, Yu),송의혁(Eui Hyeok, Song),이계복(Kye Bock, Lee) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.5

A floating photovoltaic generation system is composed of photovoltaic panel, supporting system and floating system. Since this system is installed outdoors, the effect of wind load on the structure is very large. In this study, the wind loads most affected on the floating photovoltaic generation structure were obtained by computational fluid dynamic analysis. The flow characteristics and wind loads were analyzed for various wind orientations. The analysis showed the position of the maximum wind load to the wind direction and the flow characteristic around the solar panel and floating system.

KVN의 광대역 관측 시험 및 결과고찰

오세진,오야마 토모아키,염재환,니시카와다카시,노덕규,김승래,이의겸,제도흥,변도영,이성모,정현수,Oh, Se-Jin,Oyama, Tomoaki,Yeom, Jae-Hwan,Nishikawa, Takashi,Roh, Duk-Gyoo,Kim, Seung-Rae,Lee, Eui-Gyeom,Je, Do-Heung,Byun, Do-Young,Lee, Seong-Mo,C 한국융합신호처리학회 2016 융합신호처리학회 논문지 (JISPS) Vol.17 No.2

본 논문에서는 한국우주전파관측망의 성능 확장을 위해 광대역 관측시스템의 시험 및 결과에 대해 소개한다. KVN은 1024Mbps 속도로 VLBI 관측을 수행하는데, 4주파수 동시관측을 위한 8192Mbps 관측은 정규 운영을 위해 시험하고 있다. 세계 여러 VLBI 관측국에서는 높은 정밀도와 고분해능의 천체를 관측하기 위해 광대역 관측시스템을 독자적으로 개발하거나 여러 나라와 협력하고 있다. KVN은 K/Q//W/D 밴드의 RF 신호를 주파수 변환을 하지 않고 한 주파수 대역에 대해 최대 2048MHz 대역폭을 직접 샘플링하는 OCTAD 고속샘플러를 도입할 계획이다. 따라서 KVN의 성능확장을 위한 사전연구로서 일본국립천문대와의 협력을 통하여 OCTAD 고속샘플러와 데이터 기록을 위한 OCTADISK2 고속기록기를 현장에 설치한 후, 광대역 관측시험을 통하여 성능을 확인하고 그 결과를 본 논문에서 고찰하고자 한다. In this paper, we introduce the results of the testing and observation systems for performance wideband expansion in the Korean VLBI Network(KVN). The KVN performs VLBI observations to 1024 Mbps data rate, and 8192 Mbps observing for four simultaneous observation is now evaluating for normal operation. The VLBI stations in several world countries developed their own wideband observing systems to observe the celestial objects with high precision and high resolution or are working with several countries. The KVN is planning to introduce a high-speed sampler, OCTAD, for sampling directly up to 2048 MHz bandwidth for RF signal of K/Q/W/D band in the frequency band without conversion. Therefore, as a preliminary study for the performance scalability of the KVN then through the close cooperation with National Astronomical Observatory of Japan (NAOJ), the OCTAD high-speed sampler and OCTADISK2 high-speed recorder were installed in the KVN Yonsei station, and verify the performance through a wideband.