• 제목/요약/키워드: maximum population density

검색결과 108건 처리시간 0.026초

뽕나무 경작지의 남방계지렁이 분포 (Distribution of Southern Earthworm Race in Mulberry Tree Cultivation Area)

  • 홍용
    • 환경생물
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    • 제32권3호
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    • pp.263-269
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    • 2014
  • 농생태계의 뽕나무 경작지에서 서식하고 있는 지렁이상을 확인하기 위하여, 2013년 4월부터 2014년 3월까지 조사를 하였다. 분류된 남방계지렁이는 총 5속 9종으로 다음과 같다. Aporrectodea caliginosa (Savigny, 1826), Bimastos parvus (Eisen, 1874), Eisenia fetida (Savigny, 1826), Drawida japonica (Michaelsen, 1892), Amynthas heteropodus (Goto & Hatai, 1898), Amynthas agrestis (Goto & Hatai, 1899), Amynthas corticis (Kinberg, 1867), Amynthas hilgendorfi (Michaelsen, 1895), Amynthas sp. 등이다. 장미줄지렁이 (Ap. caliginosa) 개체군 밀도 소장은 10월에 정점을 보이고 다음해 2월까지 감소하고, 성체와 미성체는 동시에 출현하며, 그들의 조성 비율은 성체 11.4%, 준성체 12.6 11%, 미성체 76% 이었다.

재해정보를 고려한 태양광발전시설의 취약성 평가에 관한 연구 (A Study on the Vulnerability Assessment of Solar Power Generation Facilities Considering Disaster Information)

  • 표희진
    • 토지주택연구
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    • 제15권2호
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    • pp.57-71
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    • 2024
  • 본 연구는 재해영향을 고려한 태양광발전시설의 평가 방법을 개발하고, 기존 시설의 취약성 분석을 목적으로 한다. 기존 시설의 재평가가 시급한 전라남도 해남군을 연구 대상지로 선정하였으며, 보다 객관적인 관점에서 취약성을 평가할 수 있도록 주성분 분석과 엔트로피 기법을 연구 방법으로 활용하여 대상지의 취약성을 평가하였다. 취약성 평가지표는 시간당 최대 일강수량, 최대풍속, 태풍 발생일수, 지속기간 5일 이상 강수일수, 1일 최대 일강수량, 불투수 면적비, 인구밀도 등 7개가 선정되었으며, 시간당 최대 일강수량, 최대풍속, 1일 최대 일강수량, 지속기간 5일 이상 강수일수 순으로 높은 가중치가 도출되었다. 도출된 가중치를 중첩한 결과 해남군 지역별로는 해남읍, 북일면 등 남동지역은 1, 2등급이, 화원면, 산이면, 문내면 등 북쪽 지역의 경우 4, 5등급이 분포하며 취약성의 차이를 보였으며, 시설별로는 2,133개 시설 중 3등급 이상 시설이 91.1%로 양호한 편이나 2등급보다 1등급의 시설 개수가 많아 이에 대한 대책이 필요한 상황으로 나타났다. 본 연구는 도시방재력을 고려하여 태양광발전시설을 평가하였다는 점에서 의의가 있으며, 향후 시설 설치 시 또는 기존 시설의 관리 및 운영 시 기초자료로서 활용될 수 있을 것으로 기대된다.

Spatial Patterns of Anthropogenic Carbon Emission and Terrestrial Net Productivity

  • Ohta, Shunji;Kimura, Ai
    • 한국환경과학회지
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    • 제15권12호
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    • pp.1087-1091
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    • 2006
  • This paper describes the current spatial patterns of the net primary productivity (NPP) of the terrestrial vegetation and carbon emission (C) in the world due to the burning of fossil fuels in order to clarify the amount of expansion of human activity. The C/NPP value varies spatially from almost zero to several tens of thousand times the local NPP. C/NPP is higher under the condition of extensive human activities due to a high human population density or when the local NPP is extremely low in severe climatic zones. In contrast, the low C/NPP areas are distributed mainly in sparsely populated districts, loading to a low impact of human activity. Although the area where C/NPP is less than 10% accounts for about 70% of the entire land area, one-third of these areas cannot contribute to carbon absorption because of low NPP with a shortage of climatic resources. Since more than half of the areas of the remaining areas are agricultural land and forest ecosystems with high NPP, the possible afforestation area was evaluated to be maximum of $30{\times}10^{6}\;km^{2}$; here only sequestrate carbons that correspond to 2% of the global total NPP are present. These analyses revealed that presently most of the areas where the NPP is high are those exclusively used by humans and that it is difficult for large-scale forest plantations to absorb a substantial amount of the carbon emitted annually by humans.

Observation of Root-knot Nematodes in the Root Gall Formed on Oriental Melon

  • Kim, Dong-Geun;Kim, Seung-Han;Lee, Joong-Hwan
    • The Plant Pathology Journal
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    • 제21권1호
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    • pp.73-76
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    • 2005
  • Oriental melon, Cucumis melo L. cv. Geumssaragieuncheon, grafted on Shintozoa (Cucurbit maxima ${\times}$ Cu. moschata) was planted in a greenhouse infested with Meloidogyne arenaria and root galls were examined five months after planting. A gram of root gall was volumed at ca. 10 cm3 and contained in an average of 363 females (170 developing and 193 matured females), 2,120 secondstage juveniles (J2), and 13,074 eggs. In addition, there was 56 J2 per $cm^3$ soil around the infested plant. An oriental melon had an average of 134.6 g of root gall (70% of total root weight) per 0.72 $m^2$ area. In a conservative estimation, an oriental melon plant could accommodate ca. 1.2 ${\times}$ $10^7$ eggs and J2 per 0.72 $m^2$. The eggs contained in root tissues could be an important inoculum source to the next crop and the fate of these eggs are well worth further investigation.

Antagonistic Potential of Fluorescent Pseudomonads and Control of Crown and Root Rot of Cucumber Caused by Phythophtora drechsleri

  • Shirzad, Akbar;Fallahzadeh-Mamaghani, Vahid;Pazhouhandeh, Maghsoud
    • The Plant Pathology Journal
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    • 제28권1호
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    • pp.1-9
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    • 2012
  • In this study, 200 isolates of fluorescent pseudomonads were isolated from different fields of East and West Azarbaijan and Ardebil provinces of Iran. These bacterial isolates were screened on the basis of a dual culture assay, the presence of known antibiotic genes, and their ability to successfully colonize roots and to promote plant growth. Twelve isolates exhibited 30% or more inhibition of mycelia growth of $P.$ $drechsleri$. Genes encoding production of the antibiotics 2,4-diacetylphloroglucinol, phenazine-1-carboxylic acid, and pyoluteorin were detected in some strains but none of the strains possessed the coding gene for production of antibiotic pyrrolnitrin. In an $in$ $vitro$ test for root colonization, the population density on roots of plants treated with most of the above strains was more than 6 $\log_{10}$ CFU $g^{-1}$ roots, with a maximum of 7.99 $\log_{10}$ CFU $g^{-1}$ roots for strain 58A. Most of the strains promoted significant plant growth in comparison to non-treated controls. In green house studies, the percentage of healthy plants in pots treated with strains 58A and 8B was 90.8% and 88.7%, respectively. The difference between these treatments and treatment with the fungicide metalaxyl was not significant.

Use of e-plastic waste in concrete as a partial replacement of coarse mineral aggregate

  • Sabau, Marian;Vargas, Johnny R.
    • Computers and Concrete
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    • 제21권4호
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    • pp.377-384
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    • 2018
  • The accelerated increase of the population growth rate in the world and the current lifestyle based on consumerism considerably increased the amount of waste generated by the human activity. Specifically, e-plastic waste causes significant damage to the environment because of its difficult degradation process. This paper aims to establish the feasibility of using e-plastic waste in concrete as a partial replacement of coarse mineral aggregate. Considering a control mix without e-plastic waste designed for a compressive strength of 21 MPa, tests on concrete mixes with 40, 50 and 60% of e-plastic waste aggregate to determine the fresh and hardened properties were carried out. A reduction in the compressive strength as the percentage of e-plastic waste increases was observed, the maximum reduction being 44% with respect to the control mix. In addition, a significant reduction as much as 22% in the density of the concrete mixes with e-plastic waste was recorded, which means that lighter elements can be produced with this type of concrete. Two new equations based on regression analysis of the experimental data from this study were proposed. These equations estimate the reduction in the compressive strength of concrete mixes with e-plastic waste aggregate at 14 and 28 days. A cost analysis and a practical alternative to introduce this waste material into the market are also presented.

남해무인도서 백도와 서귀포 인근 섶섬에서 맹독성 저서와편모조류 Gambierdiscus spp.의 출현 (Occurrence of the Toxic Benthic Dinoflagellate Gambierdiscus spp. in the Uninhabited Baekdo Islands off Southern Coast and Seopsom Island in the Vicinity of Seogwipo, Jeju Province, Korea)

  • 백승호
    • Ocean and Polar Research
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    • 제34권1호
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    • pp.65-71
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    • 2012
  • Gambierdiscus toxicus, Adachi et. Fukuyo, is a benthic ciguatoxin-producing armored dinoflagellate, often attached to macroalgae. This organism is the primary causative agent of ciguatera fish poisoning which occurs in tropical and subtropical regions. However, regardless of the fact that the population of Gambierdiscus spp. has expanded to such temperate areas from sub-trophic and trophic areas, monitoring of G. toxicus has been lacking in the Korean coastal waters of temperate areas. This study was performed at the uninhabited Baekdo Islands off the southern coast of Korea and at Seopsom Island in the vicinity of Seogwipo, Jeju Province during April and May, 2011. Cell densities of Gambierdiscus spp. on macroalgae at Baekdo and Jeju Island ranged from zero to 56.4 cells $g^{-1}$. Maximum density was recorded on the brown alga Cladophora japonica at St. 3 of Jeju Island. In particular, the cell densities of Gambierdiscus spp. were influenced by the substrate characteristics of macroalgae. In the future, the continuous monitoring of toxic benthic dinoflagellate is necessary to predict and prevent ciguatera poisoning in Korean coastal waters.

과채류 시설재배지의 뿌리혹선충 문제 (Occurrence of Root-knot Nematodes on Fruit Vegetables Under Greenhouse Conditions in Korea)

  • 김동근
    • 식물병연구
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    • 제7권2호
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    • pp.69-79
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    • 2001
  • Meloidogyne arenaria race 2 (59%) is widely distributed, followed by M. incognita race 1 (23%), and an unknown race of M. incognita (18 %) in greenhouses in southern Korea. The key character to distinguish between M. arenaria and M. incognita is excretory pore in female head. When oriental melon, Cucumis melo L., grafted on Shintozoa (Cucurbit maxima x Cu. moschata) is transplanted in February in a plastic tunnel inside a greenhouse infested with M. arenaria, nematodes produced egg masses on roots at 40 days after transplanting and the soil juveniles (J2) population reach maximum in July to 3,817/100 ㎤. Juveniles are distributed relatively uniform over the 180-cm-wide row horizontally and the highest density occurs at 0-25 cm soil depth. For the control of root-knot nematodes, rice rotation, solarization, and soil addition treatments are the most effective (P=0.05); treatments reduce number of J2 over 90% and increase yield two times. Corn retation, fosthiazate, and soil drying treatment are moderately effective, while sesame and green onion rotations are not effective. The relationship between M. arenaria and yield of oriental melon is adequately described by a linear regression model. In the test with wild Cucumis genetic sources introduced from U.S.Dept. of Agriculture (USDA), one of C.heptadactylus, two of C.anguria, two of C. anguria var. longaculeatus, nine of C. metuliferus are resistant to both species of root-knot nematodes.

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Traffic management for large-scale evacuation with public transportation and calculation of appropriate operating ratio

  • Ham, Seunghee;Lee, Jun;Lee, Sang Jo
    • Nuclear Engineering and Technology
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    • 제54권9호
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    • pp.3347-3352
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    • 2022
  • In 2013, the International Atomic Energy Agency (IAEA) changed the recommended maximum range of the Emergency Planning Zone (EPZ) to 30 km, and the Kori Nuclear Power Plant in Republic of Korea has also expanded the EPZ to 30 km, following the recommendation. As a result, metropolitan cities with a high population density are contained within the EPZ, and evacuating millions of people should be considered if the 30 km range of evacuation is to take place. This study proposes an evacuation plan using buses (public transportation) to transport people outside of the EPZ, quickly and efficiently. To verify the appropriate mode share ratio of buses that can guarantee the right of vulnerable road users and reduce traffic congestion, a model was built simulating the Kori Nuclear Power Plant in Ulsan Metropolitan City. The scenarios were established by changing the mode share ratio of buses and passenger cars by 10%. Considering a large-scale network analysis at the city level, a cell transmission model was applied to calculate the evacuation time in each scenario. The result shows that the optimal mode share ratio of buses is 40%, with a total evacuation time of 132 min, considering feasible bus fleets in Ulsan Metropolitan City.

Landsat TM/+ETM 위성영상을 이용한 몽골 Tuv지역의 토지피복변화 및 광산지역확대 추이분석 (Temporal Analysis on the Transition of Land Cover Change and Growth of Mining Area Using Landsat TM/+ETM Satellite Imagery in Tuv, Mongolia)

  • 에르뎅솜베술드;조미수;조기성
    • 한국측량학회지
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    • 제32권5호
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    • pp.451-457
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    • 2014
  • 최근 몽골 수도 울란바타르를 둘러싸고 있는 Tuv지역의 토지 황폐화가 급속도로 진행되고 있는데 이는 광산업의 발달과 인구 밀집으로 인하여 기존의 목초지가 파괴됨으로써 더욱 더 가속화 되고 있다. 따라서 본 연구에서는 Tuv지역의 도심지역과 광산지역을 대상으로 하여 토지피복의 변화 탐지와 토지황폐화에 대한 추이를 분석하기 위하여 2001년부터 2009년까지의 Landsat TM과 +ETM 위성영상을 활용하여, 정규식생지수와 무감독분류(Unsupervised Classification)의 K-Mean 알고리즘과 감독분류(Supervised Classification)의 MLC 등의 디지털 영상 분류기법을 적용하여 몽골 Tuv지역의 다중시기별 토지피복변화를 분석하였다. 그 결과 광산지역의 확장과 더불어 기후변화 및 인구밀집 등으로 인하여 토지가 황폐화되어 사막지역으로 변화되어가는 추이를 알 수 있었다.