• Title/Summary/Keyword: 먼지 대전

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Geochemical Implication of Rare Earth Element from Yellow sand (Asian Dust) at Daejeon Area, Korea: A Preliminary Study for Clarifying Source Area of Yellow Sand (대전지역 황사(아시아 먼지)내 희토류원소 분포도의 지구화학적 특성-근원지 규명을 위한 초기연구)

  • Lee, Seung-Gu;Youm, Seung-Jun
    • The Journal of the Petrological Society of Korea
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    • v.17 no.1
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    • pp.44-50
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    • 2008

  • A geochemical technique based on rare earth element geochemistry was used to clarity the source of the Asian dust (Yellow sand) in the Daejeon area. The Asian dusts were collected 4 times during 31th March- 2nd April and 25th May-27th May 2007. The Yellow sand shows PAAS (Post Archean Australian Shale)-normalized REE pattern of the flattened LREE and slightly depleted LREE without Eu anomaly, whereas the Daejeon soil has slightly enriched LREE and depleted HREE with negative Eu anomaly. Our results show that REE patterns of the Asian dust are LREE-flattened similar to those of the sediment from the south-eastern part of Ordos desert. This suggests that Asian dust in the Daejeon area might be derived from the south-eastern part of Ordos desert.

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접지형태에 따른 배관의 고체.기체 2상류에서의 정전기 대전과 화재.폭발 위험성 평가

  • ;;;;;Tsutomu KODAMA;Mizuki YAMAGUMA
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 2000.11a
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    • pp.333-339
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    • 2000

  • 현대사회의 공업화 및 도시화에 따라 NG(Natural Gas)를 포함하는 일반 가연성 가스의 누출에 의한 화재 및 폭발 재해는 매우 중요한 문제이다. 기체, 액체 및 분체가 단면적이 작은 분출구를 통해 공기중으로 이송 및 분출될 때 분출물질과 분출구와의 마찰로 인해 정전기가 발생한다./sup 1)/ 배관 내에 순수 NG가 이송·분출될 때의 대전량은 매우 작다./sup 2,3)/ 그러나, 배관 내에는 벤트스텍 등 외부에서 유입되는 먼지 또는 배관내의 부식에 의한 산화철(Fe₂O₃) 등의 분체가 포함될 수 있으며 이러한 분체가 천연가스 등과 함께 분출될 때 배관과의 마찰로 인해 대전량이 크게 상승된다./sup 3,4)/ 또한 분출되는 물질 구성입자들간 상호충돌에 의해서도 대전량은 더욱 증가하게 된다./sup 5)/(중략)

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Formulation and Application of UV-Cured Anti-stain Coating Compounds for PVC Tile (PVC 바닥상재용 광경화형 내오염 코팅액의 제조 및 응용에 관한 연구)

  • Yoon, Hyun-Jung;Ha, Jin-Wook
    • Proceedings of the KAIS Fall Conference
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    • 2009.12a
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    • pp.659-662
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    • 2009

  • 본 연구는 건축자재로 널리 사용되는 PVC 바닥상재 표면의 오염성 및 정전기로부터 보호하기 위하여 기존에 사용하는 광경화형 우레탄-아크릴 수지에 내오염/대전성을 향상시킨 광경화형 내오염 코팅액 개발에 관한 것이다. PVC 바닥상재용으로 사용되는 내오염성이 없는 우레탄-아크릴 수지에 4가 암모늄을 사용한 수용성 대전방지제와 아크릴용 대전방지제, 폴리우리탄용 대전방지제를 수지의 양 대비 함량(wt%) 5~20%로 변화하여 첨가한 후 1000rpm에서 30분간 고속 배합하여 수지의 내오염/대전성을 향상시킨 내오염 코팅액을 제조하였다. 제조한 내오염 코팅액은 코팅 층의 두께조절이 가능한 코팅(Bar-coating)을 사용하여 PVC 바닥상재에 코팅 한 후 내오염성, 대전성, 부착력, 코팅두께 등의 코팅 층 표면물성을 평가하였다. 연구결과, 수지에 수용성대전방지제 15%를 혼합하여 제조한 코팅액을 Bar-coater No.12로 코팅한 코팅표면이 전기저항($3.24{\times}10^9{\Omega}/cm^2$), 내오염도(매직 Test, 먼지부착 Test) 및 부착력(100%) 모두 가장 좋은 물성을 보였으며, 전반적으로 함량이 많을수록 전기저항과 오염도에서 우수한 것으로 나타났다. 그러나 대전방지제가 과량으로 들어간 경우 migration 현상이 보이는 것을 알 수 있었다.

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A Study on the Wind Ventilation Forest Planning Techniques for Improving the Urban Environment - A Case Study of Daejeon Metropolitan City - (도시환경 개선을 위한 바람길숲 조성 계획기법 개발 연구 - 대전광역시를 사례로 -)

  • Han, Bong-Ho;Park, Seok-Cheol;Park, Soo-Young
    • Journal of the Korean Institute of Landscape Architecture
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    • v.51 no.2
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    • pp.28-41
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    • 2023

  • The objective of the study was to develop an Urban Windway Forest Creation Planning Technique for the Improvement of the Urban Environment using the case of Daejeon Metropolitan City. Through a spatial analysis of fine dust and heat waves, a basin zone, in which the concentration was relatively serious, was derived, and an area with the potential of cold air flow was selected as the target area for the windway forest development by analyzing the climate and winds in the relevant zone. Extreme fine dust areas included the areas of the Daejeon Industrial Complex Regeneration Business District in Daedeok-gu and Daedeok Techno Valley in Yuseong-gu. Heat wave areas included the areas of Daedeok industrial Complex in Moksang-dong, the Daejeon Industrial Complex Regeneration Business District in Daehwa-dong, and the high-density residential area in Ojeong-dong. As a result of measuring the wind speeds in Daejeon with an Automatic Weather System, the average wind speeds during the day and night were 0.1 to 1.7 m/s,, respectively. So, a plan of for a windway forest that smoothly induces the movement of cold air formed in outer forests at night is required. The fine dust/heat wave intensive management zones of Daejeon Metropolitan City were Daejeoncheon, Yudeungcheon, Gapcheon-Yudeungcheon, and Gapcheon. The windway forest formation plan case involved the old city center of Daejeon Metropolitan City among the four zones, the Gapcheon-Yudeungcheon area, in which the windway formation effect was presumed to be high. The Gapcheon-Yudeungcheon area is a downtown area that benefits from the cold and fresh air generated on Mt. Gyejok and Mt. Wuseong, which are outer forests. Accordingly, the windway forest was planned to spread the cold air to the city center by connecting the cold air generated in the Seosa-myeon forest of Mt. Gyejok and the Namsa-myeon forest of Mt. Wuseong through Gapcheon, Yudeungcheon, and street forests. After selecting the target area for the wind ventilation forest, a climate map and wind formation function evaluation map were prepared for the area, the status of variation wind profiles (night), the status of fine dust generation, and the surface temperature distribution status were grasped in detail. The wind ventilation forest planning concept and detailed target sites by type were identified through this. In addition, a detailed action plan was established according to the direction of creation and setting of the direction of creation for each type of wind ventilation forest.

  • https://doi.org/10.9715/KILA.2023.51.2.028 인용 PDF