• Title/Summary/Keyword: 미소환경

Search Result 322, Processing Time 0.046 seconds

Ar 및 He기체유입에 따른 저온 대기압 DBD플라즈마에 의한 E.Coli의 노출 효과

  • Lee, Sang-Hak;Baek, Gu-Yeon;Kim, Yong-Hui;Yu, Yeong-Hyo;Choe, Eun-Ha
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2012.02a
    • /
    • pp.512-512
    • /
    • 2012
  • 최근 저온 대기압 플라즈마 장치의 개발로 대기 및 수질 환경, 바이오 메디컬분야로의 응용 연구가 활발히 진행되어 공기 중 플라즈마의 살균 및 정화효과에 대한 많은 결과가 발표되어 왔다. 본 연구는 면방전 구조의 DBD플라즈마 소스를 제작하여 He과 Ar 기체를 유입하여 미생물인 E.Coli의 변화를 관찰하였다. 면방전 구조의 DBD플라즈마 소스는 1.8 mm 두께의 유리기판위에 포토리소그라피 공정으로 미소전극을 형성하여 고밀도의 방전 셀을 형성하였으며 방전시 발생하는 열 효과를 제어하기 위하여 냉각장치를 제작하여 장착했다. 또한 유리기판과 포토 리소그라피 공정은 방전영역에 제한없이 다양한 크기의 소스제작이 가능하다. 셀 피치가 $400{\mu}m$이며 $cm^2$ 당 200여개의 방전 셀로 구성되어 있어서 기존 메쉬타입의 DBD플라즈마 장치에 비해 균일하게 플라즈마를 조사할 수 있으며 플라즈마 제트 장치에 비해서는 넓은 면적을 동시에 조사할 수 있게 되었다. Ar 과 He기체를 3 L/min의 유량으로 방전공간에 유입하면서 1kV의 구동전압으로 플라즈마를 발생 하였으며, 플라즈마의 조사시간을 20 s, 40 s, 60 s 간격으로 변화를 주어 E.Coli의 변화를 관찰하였다.

  • PDF

Potential in the Application for Biological Control of Winter Diatom Bloom Caused by Stephanodiscus hantzschii (겨울철 녹조발생 원인종 Stephanodiscus hantzschii의 생물학적제어를 위한 미소생물제재의 적용실험)

  • Kim, Baik-Ho;Kang, Yoon-Ho;Han, Myung-Soo
    • Korean Journal of Ecology and Environment
    • /
    • v.37 no.2 s.107
    • /
    • pp.236-240
    • /
    • 2004
  • To examine the algicidal effect of co-treatment of biological control agent on centric diatom Stephanodiscus hantzschii in the filtered water, an endemic algicidal bacterium (Pseudomonas putida) and a heterotrich ciliate (Stentor roselli) were iso-lated from Pal'tang reservoir, Korea. Bacterial isolate and ciliate removed 98% and 80% of the diatom for 7 days of cultivation. Co-treatments of these two agents perfectly inhibited the diatom growth, compared to the single treatment of each agent. This synergistic interaction of the bacterium and ciliate could provide an effective tool in the biomanipulation to control the diatom bloom in freshwater lakes and streams.

Study of Micro Propulsion System Based on Thermal Transpiration (열적발산원리를 이용한 마이크로 추진장치에 대한 연구)

  • Jung, Sung-Chul;Shin, Kang-Chang;Kim, Youn-Ho;Kim, Hye-Hwan;Lee, Yong-Wu;Huh, Hwan-Il
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2007.04a
    • /
    • pp.25-29
    • /
    • 2007
  • Minimization of conventional propulsion device has been studied for altitude control of micro satellite. We studied micro nozzle performance and found higher significant loss for a micro nozzle with smaller nozzle throat diameter. To overcome this loss, we proposed thermal transpiration based micro propulsion system. This new system has no moving parts and can control flow by temperature gradient, and this can be an option for potential new micro propulsion system.

  • PDF

The Hydrogen Behavior of Surface Layers of High Strength DP Thin Sheet Steels for Automobile (자동차 박강판용 고강도 DP강 표면층의 수소거동)

  • Park, Jae-Woo;Kang, Kae-Myung
    • Journal of the Korean Institute of Gas
    • /
    • v.14 no.6
    • /
    • pp.38-43
    • /
    • 2010
  • According to the lack of resources and the stringency of environmental regulations, a study of the high strength thin plate sheet steels for automobile have been become an important issue for automobile industry. However, the problem of hydrogen embrittlement of high strength sheet steels was concerned with the degradation of mechanical properties. Therefore, we studied the hydrogen behavior of surface layers of 590MPa DP sheet steels on development using by relationship the microstructure of subsurface and the distribution of micro hardnesses. Hydrogen was charged into the specimens using by the cathodic electrolytic method. The behavors of under surface layers were investigated by the observation of microstructures and the micro vickers hardness test with the amount of hydrogen charging with hydrogen charging conditions.

Foreground Pixel Alignment for Efficient Segmentation of Touching Pigs (효과적인 근접 돼지 분할을 위한 전경 픽셀 정렬)

  • Sa, Jaewon;Ju, Miso;Han, Seoungyup;Lee, Sangjin;Kim, Heegon;Chung, Yongwha;Park, Daihee
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2015.10a
    • /
    • pp.1428-1430
    • /
    • 2015
  • 감시 카메라 환경에서 돈사 내 개별 돼지들의 행동을 자동으로 관리하는 연구는 효율적인 돈사 관리 측면에서 중요한 이슈로 떠오르고 있다. 그러나 움직이는 돼지들이 근접해 있을 경우 돼지들을 개별적으로 구분하기 어렵기 때문에 근접한 돼지들을 분할하는 효과적인 방법이 필요하다. 본 논문에서는 비디오 시퀀스에서의 근접 돼지 분할 문제를 연속 프레임간의 전경 픽셀 정렬 문제로 정형화하여 해결하는 방법을 제안한다. 즉, 돈사에서 top-view로 획득한 영상 중에서 움직이는 돼지들이 근접한 경우, 돼지들의 경계가 구분된 이전 프레임의 정보를 현재 프레임에 투영한다. 이 때 개별 돼지의 움직임이 독립적임을 고려하여 이전 프레임의 개별 돼지 영역을 현재 프레임의 전경 영역에 각각 정렬함으로써 현재 프레임의 근접한 돼지를 개별적으로 분할한다. 실험결과, 제안 방법을 이용하여 3마리 이상의 근접한 돼지를 개별적으로 분할할 수 있음을 확인하였다.

Study on the Rational Construction Method Using Analysis of the Case Study of PHC Pile Foundation in Song-Do Area (송도지역 내 PHC 말뚝기초 적용사례분석을 통한 적정 시공방법 연구)

  • Lee, Byengho;Lee, Jonghwi;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
    • /
    • v.12 no.3
    • /
    • pp.55-61
    • /
    • 2011
  • Song-Do international city is the area developed in large-scale land reclamation. Song-Do area consists of reclamation layer, sedimentary layer(loose silt, soft clay and sand alternating) and residual layer from the ground surface. Therefore, using pile foundation is inevitable to build structures safely. In this area, driven PHC piles have been generally constructed in terms of environmental and economic conditions. As a result of analyzing 4 sites in Song-Do district 5 and 7 recently, the method of driving pile has many problems because of existence of rigid soil in sedimentary layer and installation of more than 30m piles. In this case, when installing piles by drive after pre-boring up to appropriate depth, the results of constructability analysis were very good. And in the economic efficiency, although 4% of construction cost rose, it was a very slight increase in comparison with improvement of workability. In the case of the stability, more than 70% compared to the allowable stress of piles was satisfied through the load test. As a result, when PHC piles is installed in Song-Do district, the proper construction method is that piles are located at bearing layer after boring rigid sand layer.

Study on the Front Detection Techniques by using Satellite Data (위성 자료를 이용한 전선 탐지 기법 연구)

  • Hwang, Do-Hyun;Bak, Su-Ho;Enkhjargal, Unuzaya;Jeong, Min-Ji;Kim, Na-Kyeong;Park, Mi-So;Kim, Bo-Ram;Yoon, Hong-Joo
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.15 no.6
    • /
    • pp.1201-1208
    • /
    • 2020
  • A mass of seawater with similar properties in the ocean is called a water mass, and the front is a sea area where two masses of different properties meet. The gradient algorithm is a method of extracting where the sea water temperature pixel changes rapidly assuming that the slope is large, and the place with the large slope is assumed to be a front. This method is able to process large amounts of satellite data at once. Therefore, in this study, we tried to find the front lines in the sea area around the Korean Peninsula by using a gradient algorithm. The study data used gridded sea surface temperature satellite data. The resolution was 1/4°, and the monthly average data from January 1993 to December 2018 were used. There were major five fronts representatively, China Coastal Front, South Sea Coastal Front, Kuroshio Front/ Kuroshio Extension Front, Subpolar Front and the Subarctic Front. As a result of comparing the distribution of front by season, more types of front were distributed in winter and spring than in summer and autumn, and the distribution range was wider.

Analysis Temporal Variations Marine Debris by using Raspberry Pi and YOLOv5 (라즈베리파이와 YOLOv5를 이용한 해양쓰레기 시계열 변화량 분석)

  • Bo-Ram, Kim;Mi-So, Park;Jea-Won, Kim;Ye-Been, Do;Se-Yun, Oh;Hong-Joo, Yoon
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.17 no.6
    • /
    • pp.1249-1258
    • /
    • 2022
  • Marine debris is defined as a substance that is intentionally or inadvertently left on the shore or is introduced or discharged into the ocean, which has or is likely to have a harmful effect on the marine environments. In this study, the detection of marine debris and the analysis of the amount of change on marine debris were performed using the object detection method for an efficient method of identifying the quantity of marine debris and analyzing the amount of change. The study area is Yuho Mongdol Beach in the northeastern part of Geoje Island, and the amount of change was analyzed through images collected at 15-minute intervals for 32 days from September 12 to October 14, 2022. Marine debris detection using YOLOv5x, a one-stage object detection model, derived the performance of plastic bottles mAP 0.869 and styrofoam buoys mAP 0.862. As a result, marine debris showed a large decrease at 8-day intervals, and it was found that the quantity of Styrofoam buoys was about three times larger and the range of change was also larger.

Effects of Organic Materials on Soil Organisms in a Korean Ginseng Field (인삼재배지 유기물 시용이 토양미생물과 미소동물에 미치는 영향)

  • Eo, Jin-U;Park, Kee-Choon;Lee, Sung-Woo;Bae, Yeoung-Seuk;Yeon, Byung-Ryul
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.43 no.2
    • /
    • pp.188-193
    • /
    • 2010
  • The aim of this study is to evaluate the effects of organic materials on soil organisms. Changes in the community structure, and population density of soil organisms (microbes, nematodes, and microarthropods) were studied in a Korean ginseng field. Phospholipid fatty acids analysis showed that the relative abundances of bacteria, fungi, and actinomycetes did not differ significantly. The aerobes/anaerobes ratio was the lowest in soils amended with leaf mold, indicating that the decomposition speed was slow. Further, the addition of leaf mold to the soil enhanced the saturated/monounsaturated fatty acid ratio and cyclopropyl fatty acid/precursor ratio, which indicated an increase in environmental stresses. Application of pig manure compost (PMC) had positive effects on the population density of nematodes, and negative effects on that of oribatid mites. The population densities of nematodes, and microarthropods remained relatively low in the plots that had been treated with leaf mold or pig manure compost. It is suggested that pre-planting soil management directed at enhancing the biological decomposition efficiency should be continued over a long period to increase the soil bioactivity in virgin soils.

Soil Microarthropod Community in the Process of Needle Leaf Decomposition in Korean Pine(Pinus koraiensis) Forest of Namsan and Kwangreung (남산과 광릉수목원의 잣나무림에서 낙엽분해과정에 관련된 토양미소절지동물군집)

  • Bae, Yoon-Hwan;Lee, Joon-Ho
    • The Korean Journal of Soil Zoology
    • /
    • v.4 no.2
    • /
    • pp.75-80
    • /
    • 1999
  • Two years-study with litter bag (mesh size : 0.4 mm, 1.7 m) was carried out from Nov., 1996 to Sept., 1998 to investigate the soil microarthropod community in the process of needle leaf secomposition of Korean pine (Pinus koraiensis) forest in Namsan and Kwangreung, where were supposed to be under different environmental selective pressures. Soil arthropoda collected from litter bags were sorted into suborders or higher taxa. Acari and Collembola were dominant groups, which were 61-68% and 27-35% of total soil arthropod in their numbers, respectively. Among Acari, Oribatida was major group, and Gamasida and Actinedida were minor groups. Abundance of Acari was a little higher in Kwangreng than in Namsan. But there was not significant difference between the arthropod community structure of Namsan and Kwangreng forest. And the different mesh sizes (0.4 mm and 1.7 mm) of litter bags could not make significantly different community structures in the litter bags. One taxon showed different pattern of population dynalics from another. But Oribatida, Gamasida and Collembola showed peak density in July, 1997. All taxa showed lower population densities in cold season i.e. Nov., Jan. and March. There was not significant difference in decomposition rate between Namsan and Kwangreng forest, and between mesh sizes of litter bags. % residual mass of needle leaf was about 40% at 22 months after litter fall.

  • PDF