• Title/Summary/Keyword: Deokjeok Island

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Evaluation of Energy Production for a Small Wind Turbine by Considering the Geometric Shape of the Deokjeok-Do Island (덕적도 지형을 고려한 소형풍력발전기 발전량 평가)

  • Jang, Choon-Man;Lee, Sang-Moon;Jeon, Wan-Ho;Lim, Tae-Gyun
    • Transactions of the Korean hydrogen and new energy society
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    • v.25 no.6
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    • pp.629-635
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    • 2014
  • This paper presents annual energy production (AEP) by a 1.5kW wind turbine due to be installed in Deokjeok-Do island. Local wind data is determined by geometric shape of Deokjeok-Do island and annual wind data from Korea Institute of Energy Research at three places considered to be installed the wind turbine. Numerical simulation using WindSim is performed to obtain flow pattern for the whole island. The length of each computation grid is 40 m, and k-e turbulence model is imposed. AEP is determined by the power curve of the wind turbine and the local wind data obtained from numerical simulation. To capture the more detailed flow pattern at the specific local region, Urumsil-maul inside the island, fine mesh having the grid length of 10m is evaluated. It is noted that the input data for numerical simulation to the local region is used the wind data obtained by the numerical results for the whole island. From the numerical analysis, it is found that a local AEP at the Urumsil-maul has almost same value of 1.72 MWh regardless the grid resolutions used in the present calculation. It is noted that relatively fine mesh used for local region is effective to understand the flow pattern clearly.

Lithology and Geology of Deokjeok Island, Western Gyeonggi Massif, Central Korea (서부 경기육괴에 위치한 덕적도의 암상과 지질)

  • Aum, Hyun Woo;Kim, Yoonsup;Cheong, Wonseok
    • The Journal of the Petrological Society of Korea
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    • v.22 no.4
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    • pp.263-272
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    • 2013
  • We investigated the lithology and petrography of granites and metasedimentary rocks in Deokjeok Island at the western margin of the Gyeonggi massif. The major lithology comprises the biotite granite that intrudes all other types of rocks. A minor amount of mylonitized porphyritic granite crops out along the southeastern coast. Metasedimentary rocks in the north are further divided into: (1) sheared quartzite-schist to the northeast; and (2) relatively less-deformed, low-grade metasedimentary rocks to the northwest. The former contains quartz grains showing undulatory extinction and subgrain aggregates as well as minor amount of primary chlorite and biotite in the muscovite-rich matrix. Metamorphic condition belongs to the greenschist facies or the biotite zone. On the other hand, the latter unit consists of meta-conglomerate, meta-sandstone, meta-pelite, and black slate. Regardless of the lithology, the intensity of deformation apparently increases eastward to develop the flow banding of quartz in the shear zone.

Air Pollutant Variations Observed at Deokjeok Island in the Yellow Sea During April 1999 to June 2000 (1999년 4월부터 2000년 6월까지 황해 덕적도에서 관찰된 대기오염물질 변화 특성)

  • 김영성;이승복;김진영;배귀남;문길주;원재광;윤순창
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.4
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    • pp.347-361
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    • 2003
  • Sulfur dioxide (SO$_2$), ozone, total suspended particulates (TSP) and PM$_{2.5}$ were measured at Deokjeok Island in the Yellow Sea during April 1999 to June 2000. Although the emission amount of air pollutants is quite low in this small island of 36 km$^2$ with 1.4 thousand inhabitants, there are pollutant sources such as an oil -firing power plant and a wharf for ferryboat. The island is also influenced from the emissions from the greater Seoul area in the east and from China in the west. In order to characterize the pollutant variations due to interactions between transport and local emissions. the correlation between variations of SO$_2$ and ozone was investigated. Mass and ion concentrations of TSP and PM$_{2.5}$ were examined on selected episode days of positive and negative correlations between the two gaseous species in spring and winter. The effects of transport were pronounced on the days of positive correlation in spring with higher concentrations of ozone and PM$_{2.5}$. TSP concentrations were also high on these days because of high wind speeds. On the days of negative correlation in spring, frequent fog associated with low wind speeds facilitated SO$_2$ oxidation and increased sulfate accompanied with decrease in nitrate in PM$_{2.5}$ and chloride in TSP. This latter phenomena was noticeable since it showed that chemical composition of fine particles could be significantly altered not only during the transport but also by local environment.ronment.

A Study on Vascular Plants of Uninhabited Islands in the Deokjeok Archipelago (덕적군도 내 무인도서의 관속식물상 연구)

  • Kim, Jung-Hyun;Yun, Jong-Hak;Nam, Gi-Heum;Lee, Jung-Hyun;Choi, Byoung-Hee;Lee, Byoung-Yoon
    • Journal of Environmental Science International
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    • v.20 no.1
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    • pp.1-23
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    • 2011
  • This study was carried out to investigate the flora of uninhabited Island in the Deokjeok Archipelago. The vascular plants which were collected in 5 times (from Jun. 2009 to Apr. 2010) were identified as 350 taxa in total, including 89 families, 231 genera, 309 species, 5 subspecies, 31 varieties, and 5 forms. There were many useful plants such as 2 taxa of Korean endemics and 2 taxa of rare plants which were proposed by the Korea Forest Service. The specially determined plants which were categorized as 5 degrees in all by the Ministry of Environment appeared as 49 taxa; Degree V was one taxon; Senecio nemorensis and IV was one taxon; Apocynum lancifolium and III was 2 taxa; Stauntonia hexaphylla, Hylotelephium spectabile and I was 45 taxa; Machilus thunbergii, Neolitsea sericea, Hedera rhombea, etc. Based on the plants which were approval objects when transfer overseas were 5 taxa, and 21 taxa of evergreen plants were recorded in the investigated area. The naturalized plants were identified as 15 taxa, and their naturalization ratio were found to be 4.2% respectively.