• 제목/요약/키워드: Seocheon

검색결과 141건 처리시간 0.022초

2020년 9월 23일 서천 화구 폭발 관측 연구 (A Study of the Seocheon Fireball Explosion on September 23, 2020)

  • 제일영;김인호
    • 한국지구과학회지
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    • 제42권6호
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    • pp.688-699
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    • 2021
  • 2020년 9월 23일 새벽 1시 39분경 전국 여러 곳에서 목격된 서천 화구는 대기권에 진입 후 두 차례 폭발했음이 전천 카메라 영상에 확인되었으며, 충격파는 한반도 서남부 지역 지진 및 인프라사운드 관측소에 기록되었다. 17개 관측소에서 측정된 화구 지진파 및 음파의 도달 시간 정보와 베이지안에 기초한 격자탐색법으로 화구 발생 위치를 추정하였다. 위치결정에는 대기권 바람 분포에 따른 음파 속도 변화를 반영하여 계산 결과의 신뢰도를 높였다. 화구 발생 위치는 36.050°N, 126.855°E, 고도 35 km로 전천 카메라 영상에서 관측된 두번째 화구 위치와 유사하였다. 서해 상공에서 한반도 내륙으로 입사하며 발생한 두 차례의 폭발이 근거리 인프라사운드 관측소에서 확인되었다. 또한 서천 화구 폭발 충격음은 장거리를 전파하여 최대 ~266 km에 위치하는 관측소에서도 기록되었으며 파형 모델링이 관측 결과를 뒷받침하였다. 인프라사운드 5개 관측소에서 측정된 두번째 화구 폭발 신호의 평균 주기는 ~0.4 s이며, 주기-폭발 에너지 관계식을 적용했을 때 서천 화구의 폭발 에너지는 약 0.3 ton TNT 폭발에 상응한다.

A revaluation of algal diseases in Korean Pyropia (Porphyra) sea farms and their economic impact

  • Kim, Gwang Hoon;Moon, Kyoung-Hyoun;Kim, Je-Yoon;Shim, Junbo;Klochkova, Tatyana A.
    • ALGAE
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    • 제29권4호
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    • pp.249-265
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    • 2014
  • As with land crops, cultivated algae are affected by various diseases ranging from large outbreaks of a disease to chronic epiphytes, which may downgrade the value of the final product. The recent development of intensive and dense mariculture practices has enabled some new diseases to spread much faster than before. A new disease is reported almost every year, and the impact of diseases is expected to increase with environmental change, such as global warming. We observed the incidence of diseases in two Pyropia sea farms in Korea from 2011 to 2014, and estimated the economic loss caused by each disease. Serious damage is caused by the oomycete pathogens, Pythium porphyrae and Olpidiopsis spp., which decreased the productivity of the Pyropia sea farms. In Seocheon sea farms, an outbreak of Olpidiopsis spp. disease resulted in approximately US $1.6 million in loss, representing approximately 24.5% of total sales during the 2012-2013 season. The damage caused by green-spot disease was almost as serious as oomycete diseases. An outbreak of green-spot disease in the Seocheon sea farms resulted in approximately US $1.1 million in loss, representing 10.7% of total sales in the 2013-2014 season in this area. However, the causative agent of green-spot disease is still not confirmed. "Diatom felt" is regarded as a minor nuisance that does not cause serious damage in Pyropia; however, our case study showed that the economic loss caused by "diatom felt" might be as serious as that of oomycete diseases. Bacteria and cyanobacteria are indigenous members of epiphytic microbial community on Pyropia blades, but can become opportunistic pathogens under suitable environmental conditions, especially when Pyropia suffers from other diseases. A regular acid wash of the Pyropia cultivation nets is the most common treatment for all of the above mentioned diseases, and represents approximately 30% of the total cost in Pyropia sea farming. However, the acid wash is ineffective for some diseases, especially for Olpidiopsis and bacterial diseases.

허베이 스피리트호 유류유출사고 지역주민의 급성건강영향 (Acute Health Effects of the Hebei Oil Spill on the Residents of Taean, Korea)

  • 이철헌;강영아;장규진;김창훈;허종일;김재연;이종구
    • Journal of Preventive Medicine and Public Health
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    • 제43권2호
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    • pp.166-173
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    • 2010
  • Objectives: On December 7, 2007, the Hebei Spirit oil tanker spilled out 12,547 kl of crude oil on the Yellow Sea 10 km away from the cost of Taean Province, Korea. As the coastline has been contaminated, local residents have been exposed to crude oil. Because the residents were showing many symptoms, we investigated the acute health effects of this oil spill on them. Methods: We conducted a cross-sectional study consisting of the heavy and moderately oil soaked area in Taean and the lightly oil soaked area in Seocheon. Ten seashore villages were selected from each area, and 10 male and female adults were selected from each village. We interviewed the subjects using a structured questionnaire on the characteristics of residents, the cleanup activities, the perception of oil hazard, depression and anxiety, and the physical symptoms. The odds ratios and 95% confidence intervals were analyzed using logistic regression analysis. The logistic regression model was adjusted for age, gender, education, smoking, the perception of oil hazard and anxiousness. Results: The more highly contaminated the area, the more likely it was for residents to be engaged in cleanup activities and have a greater chance of exposure to oil. The indexes of anxiety and depression were higher in the heavy and moderately oil soaked areas. The increased risks of headache, nausea, dizziness, fatigue, tingling of limb, hot flushing, sore throat, cough, runny nose, shortness of breath, itchy skin, rash, and sore eyes were significant. Conclusions: The results suggest that exposure to crude oil is associated with various acute physical symptoms. Long-term investigation is required to monitor the residents' health.

피막처리된 지황종자의 발아 (Germination of pelleted seeds in Rehmannia glutinosa Libosch)

  • 박충헌;심강보;김민규;박춘근;성낙술
    • 한국약용작물학회지
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    • 제7권3호
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    • pp.213-217
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    • 1999
  • 뿌리에 의한 영양번식으로 증식하는 지황은 바이러스에 심하게 삼염되어있어 종자를 이용한 우량종근을 생산할 목적으로 종자특성과 발아에 미치는 요인과 알진산으로 인공피막한 처리를 검토한 결과는 다음과 같다. 지황종자의 특성으로 협당종자수는 서천재래 61개에 비하여 지황1호가 207개로 많았고 1,000립중도 서천재래 70mg에 비하여 지황1호가 130mg으로 무거웠다. 지황종자는 당년채종('98)한 종자보다 전년도 채종 후 상온 저장한 종자에서 높은 발아율을 보여 미세립 종자지만 휴면현상이 있었고 온도 차이에 따른 발아는 차이를 보여 $15^{\circ}C$에서는 9일까지 발아하지 않았으나, $30^{\circ}C$에서는 2일후 28.5%, 6일후 41.6%로 높았다. 종자파종의 생력화를 목적으로 지황종자를 알진산 피막처리 하였을 때 파종후 20일에 발아율이 83.2% 정도였다. 알진산 처리농도는 2%의 저농도에서 발아율이 높았고 인공피막내 함유 종자수는 3개이상까지 많을수록 양호하였으며 저온처리는 초기발아가 지연되었다.

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Re-emergence of the Glossy Ibis (Plegadis falcinellus) in inland South Korea

  • Lee, Sang-Yeon;Sung, Ha-Cheol;Han, Donguk;Cha, Jin-Yeol
    • Journal of Ecology and Environment
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    • 제44권3호
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    • pp.155-161
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    • 2020
  • Glossy Ibis (Plegadis falcinellus), which has never been recorded in South Korea, appeared on Jeju Island in 2018 and re-emerged in the inland area of Seocheon-gun (South Chungcheong Province) and in Goyang-si (Gyeonggi Province) in the following year. This study aims to report the progress in observing P. falcinellus in the inland areas of South Korea in 2019 and to predict its origin region and future propensity for habitats in the country through literature review. On 5 May 2019, an individual of P. falcinellus with breeding feathers was observed in a farmland in Wolsan-ri, Seocheon-gun. Twelve days later, another one was identified in a farmland in Janghang-dong, Goyang-si, about 173 km north of Wolsan-ri. The observed birds fed and rested in the area and stayed for only a day. The individual birds spotted in South Korea in 2019 are conjectured to have come from either Southeast Asia or Australia, among areas located in East Asian-Australasian Flyway (EAAF). This is because P. falcinellus, a species with excellent dispersal capacity, forms a population in new areas during extreme environmental changes in their current habitats, especially droughts. For 2 years, P. falcinellus was observed to be migrating in spring; however, in the future, they may exhibit the same propensity for breeding and habitats as that of birds migrating in autumn. As it is a conspicuous species, effective detection of their arrival requires a survey system that classifies the country by habitat type and involves periodic and multiple observations by experts and citizens.

충남 서천 패류생산해역에서의 세균학적 위생안전성 평가 (Evaluation of Bacteriological Safety for the Shellfish growing Sea waters in Seocheon Area, Korea)

  • 변한석;송기철;이두석;심길보;임치원
    • 한국수산과학회지
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    • 제43권1호
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    • pp.25-32
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    • 2010
  • A Sanitary survey in an Important shellfish-growing area of Biin Bay in Seocheon-gun Korea, was conducted to evaluate bay conditions and compliance with the bacteriological criteria for areas designated for the production of shellfish for export. Seawater samples were collected monthly at 55 sampling stations established in the survey area from January 2006 to December 2008. Bacteriological water quality did not change in response to a small rainfall (10.0 mm), but it increased abruptly in response to rainfall to 62.5 mm The most probable number (MPN) value for total coliforms and fecal coliforms in 1, 980 seawater samples ranged from <1.8 to >1, 600 MPN/100mL and from <1.8 to 330 MPN/100mL, respectively. The geometric mean and estimated $90^{th}$ percentile value for total coliforms ranged from 2.0 to 10.3 MPN/100mL and from 7.0 to 42.6 MPN/100mL respectively. The geometric mean and estimated percentile value for fecal coliforms ranged from 1.8 to 4.0 MPN/100mL and from 1.9 to 18.3 MPN/100mL, respectively. Accordingly, the bacteriological water quality of Biin Bay met the National Shellfish Sanitation Program (NSSP) and Korea Shel1fish Sanitation Program(KSSP) criteria for areas designated for shellfish production for export in Korea.

지황 조직배양주의 수량성과 성분함량 특성 (Characteristics in Tissue Cultured Plants of Chinese foxglove(Rehmannia glutinosa))

  • 박충헌;성낙술;김선규;백기엽
    • 식물조직배양학회지
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    • 제26권3호
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    • pp.205-209
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    • 1999
  • 지황 (Rehmannia glutinosa) 우량종묘 생산을 위하여 조직배양에 의해 생산된 종묘의 포장수량성을 평가하고 지표성분인 Catalpol과 유리당 함량 특성을 비교한 결과는 다음과 같다. 조직배양주의 종근저장성은 재래종에 비하여 약간 양호한 경향이었다. 또한 근장, 근경 등의 뿌리생육이 왕성하여 조직배양주의 수량성은 서천재래종 384kg/10 a에 비하여 1년차 묘는 112%, 2년차 묘는 246%까지 증수되는 결과를 보였다. 성분함량 특성비교에서는 총당함량이 서천재래 1.86%에 비하여 조직배양 1, 2년차 묘는 각각 1.21, 1.10%를 보였고, 지표성분인 Catalpol도 서천재래 0.46%에 비하여 조직배양 1, 2년차묘는 0.4%로 약간 감소되는 경향이었다. 이상의 결과에서 지황 조직배양주의 수량성은 재래종에 비하여 증수되는 특성을 보였다. 그러나 유리당과 Catalpol 함량은 약간 감소되는 경향이었는데 모본식물과 큰 차이를 보이지는 않았다.

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위글 매치를 이용한 서천 봉선리 유적 출토 목곽고의 방사성탄소연대 측정 (Wiggle Matched Radiocarbon Dates of Wooden Warehouses Excavated at the Bongseon-ri Site in Seocheon, Korea)

  • 이광희;김수철
    • 보존과학회지
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    • 제34권1호
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    • pp.31-37
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    • 2018
  • 서천 봉선리 유적에서 출토된 목곽고의 제작 연대는 출토된 토층 및 토축부의 축조방법으로 5세기 전후로 추정되었다. 정확한 연대를 확인하고자 목곽부재 3점에 대해 위글매치를 이용한 방사성탄소연대분석을 실시하였다. 목곽부재 1(BSMG 01)의 최외각 연륜은 95.4% 신뢰구간에서 AD 431~551년, 목곽부재 2(BSMG 06)는 AD 460~570년으로 확인되었고 목곽부재 3(BSMG 12)은 AD 240~430년 또는 AD 490~510년으로 산출되었다. 목부재 3점의 공통 연대는 AD 490~510년으로 고고학적으로 추정된 연대와 일치하였으며, 위글매치를 이용한 방사성탄소연대측정의 정확성을 입증할 수 있었다.

농촌지역 기후변화 취약성 평가에 관한 연구 - 서천군을 대상으로 - (Climate Change Vulnerability Assessment in Rural Areas - Case study in Seocheon -)

  • 이경진;차정우
    • 농촌계획
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    • 제20권4호
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    • pp.145-155
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    • 2014
  • Since greenhouse gas emissions increase continuously, the authorities have needed climate change countermeasure for adapting the acceleration of climate change damages. According to "Framework Act on Low Carbon, Green Growth", Korean local governments should have established the implementation plan of climate change adaptation. These guidelines which is the implementation plan of climate change adaptation should be established countermeasure in 7 fields such as Health, Digester/Catastrophe, Agriculture, Forest, Ecosystem, Water Management and Marine/Fisheries. Basically the Korean local governments expose vulnerable financial condition, therefore the authorities might be assessed the vulnerability by local regions and fields, in order to establish an efficient implementation plan of climate change adaptation. Based on this concepts, this research used 3 methods which are LCCGIS, questionnaire survey analysis and analysis of existing data for the multiphasic vulnerable assessment. This study was verified the correlation among 7 elements of climate change vulnerability by 3 analysis methods, in order to respond climate change vulnerability in rural areas, Seocheon-gun. If the regions were evaluated as a vulnerable area by two or more evaluation methods in the results of 3 methods' comparison and evaluation, those areas were selected by vulnerable area. As a result, the vulnerable area of heavy rain and flood was Janghang-eup and Maseo-myeon, the vulnerable area of typhoon was Janghang-eup, Masan-myeon and Seo-myeon. 3 regions (i.e. Janghang-eup, Biin-myeon, Seo-myeon) were vulnerable to coastal flooding, moreover Masan-myeon, Pangyo-myeon and Biin-myeon exposed to vulnerability of landslide. In addition, Pangyo-myeon, Biin-myeon and Masan-myeon was evaluated vulnerable to forest fire, as well as the 3 sites; Masan-myeon, Masan-myeon and Pangyo-myeon was identified vulnerable to ecosystem. Lastly, 3 regions (i.e. Janghang-eup, Masan-myeon and Masan-myeon) showed vulnerable to flood control, additionally Janghang-eup and Seo-myeon was vulnerable to water supply. However, all region was evaluated vulnerable to water quality separately. In a nutshell this paper aims at deriving regions which expose climate change vulnerabilities by multiphasic vulnerable assessment of climate change, and comparing-evaluating the assessments.