• 제목/요약/키워드: Crown density

검색결과 183건 처리시간 0.026초

산불발생지의 표면유출수와 토양침식량에 관한 연구 (Studies on the Surface Runoff and Soil Erosion in the Forest Fire Area)

  • 정원옥;마호섭
    • 한국환경복원기술학회지
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    • 제4권3호
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    • pp.1-9
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    • 2001
  • The purpose of this study was to evaluate the burning impacts of the surface and crown fire occured in yongsan-ri meongsok-myun of chinju-city, Gyeongnam. Environmental influences like surface runoff and soil erosion changes were investigated by comparisons analysis between burned and unburned area about some initial effects after fire. The results obtained from this study were as followed; 1. The average amount of surface runoff in burned area was more 1.7 times than in unburned area. But it was gradually tend to decrease in burned area as times passed. 2. Factors significantly correlated to amount of surface runoff in burned area shown in order to unit rainfall, accumulated rainfall and sand content, as 0.9466 of multiple correlation coefficient, where as the factors in unburned area were unit rainfall, soil erosion, bulk density and soil hardness, as 0.9738 of multiple correlation coefficient. 3. The average amount of soil erosion in burned area was more 11.2 times than in unburned area. But it was gradually tend to decrease in burned area as times passed. 4. Factors significantly correlated to amount of soil erosion in burned area were surface runoff and unit rainfall, as 0.6305 of multiple correlation coefficient. The factors in unburned area shown in order to surface runoff, sand content, bulk density and unit rainfall, as 0.7879 of multiple correlation coefficient.

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Immunohistochemical Evaluation of Angiogenesis Related Markers in Pyogenic Granuloma of Gingiva

  • Seyedmajidi, Maryam;Shafaee, Shahryar;Hashemipour, Golnarsadat;Bijani, Ali;Ehsani, Hodis
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권17호
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    • pp.7513-7516
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    • 2015
  • Background: Pyogenic granuloma is a common non-neoplastic connective tissue proliferation. ICAM-1 and VCAM-1 are vascular adhesion molecules and CD34 is a marker for evaluation of angiogenesis. The purpose of this study was to compare the immunohistochemical expression of ICAM-1, VCAM-1 & CD34 in oral pyogenic granuloma and normal gingiva. Materials and Methods: This study was performed on thirty five formalin-fixed, paraffin embedded samples of gingival pyogenic granuloma. Also we used thirty five paraffined blocks of normal gingiva as control group which were taken from crown lengthening surgery. We employed immunohistochemistry staining for our prepared microscopic slides using monoclonal mouse anti-human antibodies against ICAM-1 (CD54), VCAM-1 (CD106) and CD34. Slides were examined under light microscope and then the mean amount of stained vessels also known as microvascular density (MVD) in highly vascularized areas (hot spots) was measured. Paired t-test and repeated measures ANOVA were used to compare the difference between quantitative variables and Chi-square test for qualitative variables in different groups. Pearson correlation coefficient was used to compare relations between quantitative variables. P<0.05 was considered significant. Results: The mean of MVD for ICAM-1, VCAM-1 and CD34 was significantly higher in pyogenic granuloma than normal gingiva (p<0.001 & p<0.001 & p<0.001, respectively). Expression of CD34 in pyogenic granuloma was significantly higher than ICAM-1 and VCAM-1 (P<0.001). Besides, expression of ICAM-1 in normal gingiva, was significantly lower than two other markers (p<0.001). Conclusions: Regarding the results, it seems that ICAM-1, VCAM-1 and CD34 are useful biomarkers in evaluation of vascular and inflammatory lesions such as gingival pyogenic granuloma and the results indicate the role of these biomarkers in pathogenesis of oral pyogenic granuloma.

지리산 반달가슴곰 상사리 입지와 조망 특성 (The Characteristics of the Sites and Prospects of the Bear Shelves of Asiatic Black Bear (Ursus Thibetanus) on Jirisan National Park)

  • 유재심;박종화;우동걸
    • 한국환경복원기술학회지
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    • 제15권4호
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    • pp.41-49
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    • 2012
  • The objective of this study is to investigate the characteristics of the location and prospects of the bear shelves built by Asiatic black bears in the Jirisan National Park. Previous researchers have been analyzed bear shelves in terms of places for resting and eating, but we are going to analyze based on the prospect-and-refuge theory. Characteristics of the sites of bear shelves are measured through field survey and topographic analysis by using digital elevation model (DEM). The normalized difference vegetation index (NDVI) is used to evaluate the optimum location of bear shelves in terms of crown density. Man-made objects are identified by viewshed analysis based on geographical information system (GIS). Findings of this paper can be summarized as follows. First, most bear trees are located deep inside of the mountainous national park, slopes of 30~40 degrees, altitude of 400~1,200m, and relatively low vegetation density with NDVI value of 0.4~0.6 compared to the average NDVI of the park. Second, the average height of bear shelves is 12.44m, or 74% of the average height of bear trees. They are located at suitable places to observe nearby trails and other park facilities. Third, man-made objects within the 100m radius of bear trees include lodge, bear training center, beekeeping camp, and hiking trails. Thus we may temporarily conclude that one of the main criteria of the bear tree selection in the park has been to identify optimum places for the monitoring of human activities in their habitat.

숲 가꾸기 임지의 소나무좀 발생과 후식 피해 (Secondary Damage and Adult Emergence of Pine Bark Beetle (Blastophagus piniperda) in Tended Forests)

  • 구관효;이정환;김종갑
    • 한국농림기상학회지
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    • 제7권4호
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    • pp.258-264
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    • 2005
  • The objectives of this study were to study 1) emergence of pine bark beetles, 2) larval density in residual timber on Idlest land by each felling season, and 3) the secondary damage rates in the tended forest. Pine forest land which had undergone tending had a higher secondary damage ratio $(59.6\%)$ by pine bark beetles than forest land that was not tended $(2.8\%)$. The number of escape holes averaged 11.3 0.31 per $250 cm^2$ on the bark of leaf trees in the tended forest. The number of escape holes was higher in the Jinju site than in the Hamyang site. The larval habitat density of pine bark beetles as compared with each felling period was higher after mid-October than in forests tended early in October. Thus, forests should be tended before early October in order to prevent secondary damage from pine bark beetles. Secondary damage in the tended forest was higher in the upper part $(75.5\%)$ of the tree crown than in the lower part $(49.2\%)$. The damage was higher in terminal shoots $(80\%)$ than in lateral shoots $(48\%)$. Therefore, secondary damage by pine bark beetles can cause deterioration of the elongation growth of the forest trees. In conclusion, if by-products of tended pine forest forests are neglected, they will be utilized as a propagation site for pine bark beetles (Blastophagus piniperda L). The propagated adults will damage the tender shoots of the leaf trees and thus seriously limittheir elongation.

산불화재 감식을 위한 연소생성물의 응용에 관한 연구 (A Study on Application of Combustion Products for Forest Fire Investigation)

  • 박영주;이해평
    • 한국안전학회지
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    • 제26권4호
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    • pp.111-119
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    • 2011
  • This study was designed to provide basic data applicable to fire investigation through consideration of combustion products and propose vulnerability of combustibles through analysis of $CO_2$ emission. In order to achieve these research objectives, characteristics of combustion products such as smoke release rate of each part(raw leaves, branches and barks), $CO_2$ emission and ash production were considered targeting on 6 oak species(Quercus variabilis Blume, Quercus aliena Blume, Quercus serrata, Quercus mongolica Fisch, Quercus dentata Sapling and Quercus acutissima) using cone calorimeter and smoke density tester. As a result, it was found that raw leaves release smoke more relatively than branches and barks, when they burn, and that Quercus variabilis Blume has the highest smoke density. Also, Quercus acutissima released CO and $CO_2$ which are respectively, 6.67 times and 1.43 times more than Quercus variabilis Blume with low $CO_2$ emission. In addition, branches released CO and $CO_2$ more relatively. There was a big difference in ash production among raw leaves(3.1 g), branches(10.5 g) and barks(16.43 g). It was identified that Quercus serrata produces ashes which are nearly 9.95 times more than Quercus variabilis Blume. It demonstrates that Quercus serrata contains relatively higher minerals and that Quercus variabilis Blume can leave lots of traces like stain and carbonization, as it releases smoke a lot and it's difficult to predict visibility, when a forest fire breaks out in its community area. It is also considered that smoke particles containing oil in the air leave strain on the surface of a tree, and that CO and $CO_2$ emission increases, when crown fire to burn branches breaks out.

한반도 특산식물 개느삼의 개체군 특성 (Population Characteristics of Echinosophora koreensis (Nakai) Nakai, a Endemic Plants in Korea)

  • 김소담;문애라;안종빈;정지영;박완근;손성원
    • 한국환경생태학회지
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    • 제34권1호
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    • pp.18-26
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    • 2020
  • 개느삼은 한반도의 일부 지역에 제한적으로 분포하는 특산식물이며, IUCN Red List의 'Endangered'로 지정된 희귀식물이다. 본 연구는 자생지의 환경변화로 쇠퇴 위협이 있는 개느삼의 분포 패턴과 개체군 구조를 조사 분석하여 향후 개느삼 개체군의 동태 및 지속성 파악을 위한 기초 자료 활용에 목적이 있다. 개느삼 개체군의 특성을 파악하기 위해 양구, 춘천, 홍천 3개 지역에 각각 2~3개의 대방형구(20m×30m)를 능선을 기준으로 설정하고, 대방형구 안에 4~7개 Transect상의 소방형구(1m×1m)를 2m 간격으로 각각 10개씩 총 530개를 설정하여 출현 개체 수 및 결실 개체 수, 개체 높이 등을 측정하였다. 확보된 종발생정보를 IUCN Red List ver 3.1의 평가기준 B를 적용하여 기존 IUCN에 평가된 범주와 비교분석하였다. 조사된 세 개 지역의 평균 개체 밀도는 3.47본/㎡로 나타났으며, 지역별로 양구 3.95본/㎡, 춘천 3.37본/㎡, 홍천 2.87본/㎡이었다. 한편, 개체군의 결실률(결실 수/개체 수)은 0.0038으로 전체 출현 개체 1,837본 중에 7본만이 결실된 것으로 나타나 생식생장(sexual reproductive) 보다는 영양생장(vegetative reproduction) 비율이 매우 높을 것으로 추정된다. 조사된 세 지역의 소방형구 개체 밀도의 분포 경향을 분석한 결과, 개느삼은 수관 열림이 높은 산지 능선을 중심으로 수관 열림이 낮은 숲 중심부로 갈수록 개체 밀도가 감소하는 경향을 보여줌으로써, 광량이 개느삼 개체의 생육에 매우 중요한 요소일 것으로 추정된다. 한편, 방형구내 출현하는 전체 개체의 높이를 분석한 결과 2.3~68.5cm로 나타났으며, 평균 20.1cm로 조사되었다. 개체 높이를 바탕으로 개느삼 개체군의 stage-structure를 분석한 결과 15~20cm를 기점으로 개체 높이가 높아질수록 점차 출현빈도가 감소하는 경향을 보여주었으며, seedling으로 추정되는 10cm 이하의 개체들의 비율도 매우 낮게 나타남으로써 향후 모니터링 자료를 바탕으로 개체군의 지속성에 대한 분석이 필요할 것으로 보인다. 한편, 확보한 종발생정보를 바탕으로 산출된 점유면적은 200㎢로 나타나 IUCN Red List 기준(criteria) B 적용 시 EN 범주를 충족하는 것으로 나타났다.

임상별 임간인삼의 생육과 최적환경에 관한 연구(I) (A Study on the Growth and Environments of Panax ginseng in the Different Forest Stands (I))

  • 우수영;이동섭
    • 한국농림기상학회지
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    • 제4권2호
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    • pp.65-71
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    • 2002
  • 임간인삼의 생육특성을 조사하기 위해서 활엽수, 침엽수, 혼효림 3가지 연구지를 선정하였다. 연구지는 이미 산지인삼이 비슷한 연령으로 분포하는 지역을 선정하였고 대상 연구지의 환경과 생육특성 등을 조사하였다. 세 임분 공동적으로 상층목의 평균 수령이 20~25년이고 평균 DBH는 14~17cm였다. 평균 수고는 약 7.8~8.5 m 정도였다. 하층식생으로는 마, 더덕, 실새풀 등의 초본류가 차지하고 있다. 산지인삼의 생육은 활엽수림에서 생장한 산지인삼이 침엽수나 혼효림의 것보다 약간 좋은 것으로 나타났지만 그 차이가 미세해서 내년도에 연령이 많은 산지인삼을 대상으로 더 자료를 수집할 필요가 있다. 앞으로 이러한 기초자료를 토대로 생리적인 자료를 확보하는 것이 필요하고, 그러기 위해서 광합성능력, 기공의 형태, 증산량 등의 생리적인 자료를 확보해야 한다.

도시 주요조경수종의 연간 $CO_2$흡수 (Annual $CO_2$ Uptake by Urban Popular Landscape Tree Species)

  • 조현길;조동하
    • 한국조경학회지
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    • 제26권2호
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    • pp.38-53
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    • 1998
  • This study quantified annual net carbon uptake by urban landscape trees and provided equations to estimate it for Ginkgo biloba, platanus occidentalis, Zelkova serrata and Acer palmatum, based on measurement of exchange rate for two years growing seasons from Sep., 1995 to Aug., 1997. The carbon uptake was significantly influenced by photosynthetic capacity, photon flux density and pruning. Ginkgo biloba showed the highest rate of net CO\sub 2\ uptake per unit leaf area and Acer palmatum did the lowest rate among those species. A tree shaded by adjacent building over the growing seasons showed net CO\sub2\ uptake per unit leaf area much lower than another tree of the same species less shaded. Annual net carbon uptake per tree was 19kg for Zelkova serrata, but only 1 kg for Ginkgo biloba and Platanus occidentalis with crown volume dwarfed from pruning. One Zekoval serrata tree annually offset carbon emission from consumption of about 32 liter of gasoline or 83 kWh of electricity. Strategies to improve CO\sub 2\ uptake by urban landscape trees include planting of species with high potosynthetic capacity, sunlight-guaranteed road and building layout for street trees, planting of shade-tolerant species in the north of buildings, and relocation of utility lines to underground and minimized pruning.

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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.

타이어 고무배합물의 초탄성을 고려한 레이디얼 타이어의 팽창에 관한 유한요소해석 (F.E. Analysis of the Radial Tire Inflation Using the Hyperelastic Properties of Rubber Compounds Sampled from a Tire)

  • 김용우;김종국
    • 한국자동차공학회논문집
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    • 제11권4호
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    • pp.125-134
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    • 2003
  • In this study, Mooney-Rivlin 1st model and Mooney-Rivlin 3rd model are adopted as strain energy density functions of the rubber compounds of a radial tire. It is shown that the FE analysis using Mooney-Rivlin models for rubber compounds may provide good approximations by employing the appropriate strain range of experimental stress-strain data in a way to describe the stress-strain relationship accurately. Especially, Mooney-Rivlin 3rd model gives an accurate stress-strain relationship regardless of the fitting strain range used within the strain of 100%. The static nonlinear FE analysis of a tire inflation is performed by employing an axisymmetric model, which shows that the outside shapes of the tire before and after inflating the tire agree well with those of the real tire. Additionally, the deformations at crown center and turning point on sidewall, distribution of belt cord force, interlaminar shear strain are predicted in terms of variation of belt cord angle which is known as the most influential factor in inflation behavior of a tire.