• Tunnel and Underground Space
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• v.8 no.3
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• pp.194-199
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• 1998

This research was aimed to figure out the trend of dust diffusion at open pit limestone mine for assessing the environmental impacts on the high voltage power transmission line. It is rather easy to assess the dust generation and size distribution of limestone dust at the blasting site, but it is very hard to assess the expected area of dust diffusion and amount of dust fall by the distances from the dust source. In this research, a 3-dimensional fluid dynamic simulation software (3D-Flow) was used for analysing the above mentioned matters to assess the impacts to the insulators on the transmission tower by the blasting dust. It was verfied that the 3D-Flow is reliable tool for simulating dust movement, and the limestone dust is not much hazardous to the power transmission line.

• Explosives and Blasting
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• v.30 no.2
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• pp.9-20
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• 2012

These days, mining industry prefers underground development for large mining because of exhaustive minning resources and large drafts and mining cavities thanks to extensive distribution of heavy excavation machines. In a mining design, to control collapse of cavities and secure stability, design of cavities and pillars are considered as very important. Therefore, this study obtained a prediction equation of blasting vibration through instrumentation for underground cavities. And we obtained theoretical shock vibration imposed on pillar through fragmentation analysis and measurement of flyrock distance. To examine the influence of pillar in underground mining blasting, we carried a finite element analysis and compared the result with prediction equation of blasting vibration, and shock vibration of flyrock when a impact was imposed on pillar and theoretical shock vibration.

• Korean journal of applied entomology
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• v.52 no.3
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• pp.205-213
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• 2013

Forest fires disturb communities of forest-dwelling insects by killing or dispersal. Species diversity, species composition, and functional guilds of ant communities will be changed following forest fires. A survey of ants was conducted to find changes in ant communities after a large fire occurred in Goseong within Gwangwon province in South Korea in 1996. In total, 1,308 ants representing 16 species were collected; 696 ants representing 15 species were collected at the burned site, and 612 ants representing 13 species were collected at the unburned site. Contrary to the general expectation which predicts a decrease of diversity and abundance after fire, abundance, species diversity, species composition, and functional guilds of ant communities did not differ between the burned site and the unburned site. Furthermore, estimated species richness was significantly higher at the burned site than at the unburned site. However, monthly occurrences of ants (abundant species and pooled) were different between the burned site and the unburned site. Ants were more abundant at the burned sites than the unburned site just after the fire (May 1996). However, they were more abundant at the unburned site than the burned site in autumn (September and October 1996). This phenomenon might be caused by environmental change (e.g., decrease of soil moisture). In conclusion, the fire did not significantly change ant fauna, as fire in spring cannot destroy ant colonies that are wintering in deep soils.

• The Korean Journal of Ecology
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• v.16 no.4
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• pp.429-438
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• 1993

This is a report on the early vegetation and the secondary succession in the burned area of SeobJe-Go1 of $IIwasan-MY\v{o}n,\;Y\v{o}ngch\v{o}n-Gun,\;Ky\v{u}ngsangbuk-do$ Province. The forest fire occurred on April 8, 1982 and the pine forest and its floor vegetation were burned down. The investigation was done six times from August 20, 1982 to August 13, 1983. The results are summarized as follows: the floristic composition of burned areas $B_1,\;B_2$, and unburned areas $U_1,\;U_2$ were composed of 25, 23, 32, and 27 kinds of vascular plants. respectively. The biological spectra showed the $H-D_1-R_5-e$ type in both the burned and unburned areas. The species of Arundinella hirta, Miscanthus simnsis var. purpurascens and Cares hurnilis var. nana were dominant species in the burned area, while Pinus densiflorrr, Corex humilis var. nana and Rhododendron mucronulatum var. ciliafum were dominant species in the unburned area. Degree of succession of the unburned area was comparatively higher than that of the burned area. Species diversity index and evenness index of the burned area were similar to those of the unburned area. Indices of similarity in sampling sites showed that $B_1\;and\;B_2$ stands were the most similar. pH, total nitrogen, available phosphorus and exchangeable potassium of soil increased but organic matter and total organic carbon decreased after fire.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.223-224
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• 2003

포장도로에서 발생되는 미세먼지는 주로 자동차의 운행에 의한 직접 배출되는 입자와 도로 표면에서 비산되는 토양입자 그리고 타이어나 브레이크 패드의 마모에 의한 고무 및 석면 둥 다양한 배출원에 의해 발생되는데, 도로 주변의 배출원에 의해 많은 영향을 받을 것으로 판단된다. (최금찬등, 1996) 특히 인천에는 많은 비산먼지 배출원이 산재하여 있어, 이 들 배출원들의 영향이 여타 대도시보다 클 것으로 판단된다. 따라서, 본 연구에서는 인구와 교통량이 많고 공업활동이 활발한 인천지역의 주요 포장도로(H-ADT: High Average Daily Traffic, 5,000대/일 이상인 도로)에서 채취한 silt를 주거지역, 공업지역, 상업지역, 기타지역별로 채취하여 화학적 성분분석을 통해 지역별 특성을 조사하여, 각 지역 별 포장도로에서의 silt의 기원이 무엇인지를 추정하는 기초자료를 구축하고자하였다. (중략)

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.31 no.9
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• pp.16-23
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• 2002

현재 우리나라는 1980년대 후반부터 도시폐기물 소각시설을 설치하기 시작하여 전국적으로 20 여곳의 대형 소각장이 가동되고 있으며 대기오염 방지 기술도 발전에 발전을 거듭하여 불과 10 여년 동안에 선진국 수준의 대기오염 배출기준을 만족하는데 아무 문제가 없을 정도로 되었다. 그러나 소각후 발생 하는 소각재의 경우 비산재는 고형화등의 처리 후 매립하고 바닥재는 별도 처리없이 매립하는 실정이어서 매립 후 시간이 흐를수록 매립된 소각재에서 용출되는 다이옥신과 소각재 중에 포함된 중금속 등에 의한 토양오염과 수질오염의 우려가 남아 있는 것이 사실이다. 소각후 남는 소각재는 폐기물량의 약 15 %, 비산재는 약 1.5 % 정도 발생하는 것으로 볼 때 매립은, 특히 다음 세대에 유산으로 남겨진다는 점에서 더 이상 적절하지 않은 해결책으로 생각되며 유럽과 일본 등 선진국에서는 이미 이와 같은 소각재에 대한 무해화 처리기술이 개발되고 속속 상용화되고 있으므로 우리나라도 하루빨리 열분해용융시설등 신기술을 개발하거나 도입하여 세계적 환경 기술경쟁 에서 선진국과 어깨를 나란히 함은 물론 청정한 국토를 후손에게 물려줄 수 있도록 하는 대책이 강구되어 야 할 것이다. 본 고에서는 폐기물 처리기술의 세계 적 동향을 살펴보고 폐기물의 완전 자원화에 성공한 대우 써모셀렉트 열분해용융 기술의 특성에 대해 소개하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.1
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• pp.182-188
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• 2008

The compounds of recycled polyethylene(PE) and fly-ashes were prepared. Polymers used were sorted PE from mixed plastics of household waste and Low Density Polyethylene(LDPE) and Linear Low Density Polyethylene(LLDPE) recycled from the scrap of packaging film plants. Fly-ashes were from the power plant and from the household waste incinerator. The tensile strength of recycled LDPE and LLDPE compounds decreased and the flexural modulus increased with greater amount of the power plant fly-ash. Anthracite fly-ash gave rise to slightly higher tensile and flexural strength of the LLDPE mixtures than bituminous coal fly-ash presumably due to higher content of unburned carbon. The incinerator fly-ash introduced to household waste PE enhanced both tensile strength and flexural modulus of the compounds. When LDPE and household waste PE were used together, the synergistic effect of incinerator fly-ash to household waste PE was offset by reduced crystallization of LDPE due to the filler particle. The compounds of household waste PE and incinerator fly-ash might be applied to structural materials for such as sewage pipe, which reduces the waste treatment cost and conserve the environment and resources.

• The Korean Journal of Ecology
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• v.22 no.3
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• pp.145-153
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• 1999

Authors report the changes of the community structure and secondary succession after fire in Mt. Samma (333 m). Approximately six ha of the red pine (Pinus densiflora) forest and its floor vegetation were burned and cutted down. The vegetation and soil properties were investigated in the burned and unburned sites from April to October, 1998. The dominant species based on SDR₃ in the burned site were Lespedeza cyrtobotrya (96.87), Quercus serrata (77.90), Cyperus amuricus (46.22) and Miscanthus sinensis var. purpurascens (38.33), whereas the dominant species in the unburned site were Pinus densiflora (100.00) and Q. variabilis (66.10) at the tree layer, Q. serrata (100.00) and Zanthoxylum schinifolium (29.64) at the shrub layer., and Q. serrata (76.30) and M. sinensis var. purpurascens (72.84) at the herb layer. The biological spectra based on SDR₃ were Th-D₁-R/sub 5/-e for the burned and H (M)-D₁-R/sub 5/-e type for the unburned site, respectively. The index of similarity (CCs) between the burned and unburned sites was 0.41. The degree of succession (DS) were 609 for the burned and 1168 for the unburned site, respectively. The species diversity (H) and evenness indices (e) of the burned site were lower than those of the unburned site, but the dominance indices (C) was higher in the burned site. In the analysis of soil properties, pH, the content of NO₃/sup -/-N, available phosphrous, and exchangeable cations (K/sup +/, Ca/sup 2+/, Na/sup +/, Mg/sup 2+/) in the burned site were higher than those in the unburned site, whereas the contents of organic matter, total carbon, total nitrogen and NH₄/sup +/-N were lower in the burned site. The results show that dominant species in the burned site change from Miscanthus-Lespedeza→Lespedeza→Quercus and finally to Quercus forest, and the changes of soil properties also affect the early vegetational succession after fire.

• Journal of Korean Society of Disaster and Security
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• v.10 no.2
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• pp.29-34
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• 2017

LPG is a substance that requires a lot of attention because it can cause fatal damage to people and environment when an accident occurs. LPG is frequently accidents in transportation facilities as well as fixed facilities, among which LPG tank lorries are the most frequent accidents. When the LPG tank is evacuated, the LP gas leaks into two phases, leaks mostly to the gas and leaks to some liquid. At this time, the leaked gas will also sink downward because it is heavier than air, and if it continues to leak, it may form an explosion and explode by the ignition source. The purpose of this study is to present the evacuation distance by analyzing the effect distance of the LPG liquefied petroleum gas in the event of explosion. As a result of calculation of the scattering radius of the fragment, the cylinder fragment was scattered up to 561 m. Therefore, it is appropriate to set the distance to be escaped when the LPG tanker leaks to 561m or more.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.269-270
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• 2003

에어로졸은 자연활동으로 인하여 발생하는 것과 인위적인 산업 활동으로 인하여 발생하는 것 두 가지로 나누어진다. 황사는 바람에 의해 토양에서 대기 중으로 배출되어지는 대표적인 자연 발생적인 에어로졸이라고 할 수 있는데, 중국의 사막지역 및 몽고 내륙지역 등에서 발생한다고 알려져 있으며, 발생원인은 건조지대를 지나는 저기압의 후면에서 강한 상승기류에 의해서 토양 입자들이 대기 중으로 비산되며, 40∼50m/s의 제트기류를 타고 한반도, 일본, 알루샨 열토와 하와이까지 이동한다고 알려져 있다(Arao et al., 1986;Iwasaka, 1988). (중략)