• Journal of Korean Society of Forest Science
• /
• v.89 no.3
• /
• pp.287-296
• /
• 2000

This study was carried out to examine and compare the changes of inhabitation of soil microarthropoda after forest fire between different types of forest; i.e. the coniferous forest (Mt. Chocdae) and the broad-leaved forest (Samsinbong in Mt. Chiri). The individuals of soil microarthropoda found at the burned and unburned areas of Samsinbong and Mt. Chocdae were 12 orders in 5 classes, and individuals of Insecta and Arachnida 98% of them. In respect of classification groups, Collembola order was high at the burned and unburned areas of coniferous forest, while Acari order was high at the broad-leaved area. When classified by soil depth, the total number of soil microarthropoda individuals inhabiting at Samsinbong, the broad-leaved forest, was 25,342 and 37,350 at 1~5cm depth of burned and unburned areas respectively, while at 5~10cm depth the number turned out 9,722 and 15,906. Soil microarthropoda individuals of unburned area was 1.6 times higher than for the burned area. At the coniferous forest, the number marked 31,665 and 51,431, respectively for 1~5cm depth of burned and unburned area, and 10,189 and 13,202 for 5~10cm depth. Here also, the number for the unburned area was examined to be 1.4 times higher than for the burned area.

• Journal of Bio-Environment Control
• /
• v.31 no.2
• /
• pp.114-124
• /
• 2022

The Saemangeum has a dry surface characteristic with a low moisture content ratio due to the saline and silt soil, so the vegetation cover is low compared to other areas. In areas with low vegetation cover, wind erosion has a high probability of scattering dust. If the vegetation cover is increased by cultivating crops that can withstand the Saemangeum reclaimed environment, scattering dust can be reduced by reducing the flow rate at the bottom. Thus, the purpose of this study is to analyze the effect of suppressing the generation of fine dust and scattering dust by cultivating winter forage crops on the Saemangeum reclaimed land. While growing 0.5 ha of barley and 0.5 ha of triticale in Saemangeum reclaimed land, the concentration of fine dust was monitored according to agricultural work and growth stage. Changes in the concentrations of PM-10, PM-2.5, and PM-1.0 were monitored on the leeward, the windward and centering on the crop field. As a result of monitoring, PM-1.0 had little effect on crop cultivation. the concentration of PM-10 and PM-2.5 increased according to tillage and harvesting, and tillage had a higher increasing the concentration of PM-10 and PM-2.5 than that of harvesting. According to the growth stage of crops, the effect of suppressing scattering dust was shown, and the effect of suppressing scattering dust was higher in the heading stage than in the seedling stage. So, it was found that there was an effect of suppressing scattering dust other than the effect of land covering. Through this study, it was possible to know about the generation and suppression effect of scattering dust according to crop cultivation.

• Economic and Environmental Geology
• /
• v.54 no.5
• /
• pp.561-572
• /
• 2021

Aggregate collection is taking place in many areas in Korea, resulting in large cut slopes or large amounts of cut rocks. If the development site for such aggregate collection is a stratum accompanied by sulfide minerals, Acid Rock Drainage (ARD) may occur, which may cause environmental pollution in the development site and surrounding areas. As a result of the study on forest aggregate samples, most of the samples were classified as acid-forming potential samples, and among them, some samples from Gwangju, Goyang, and Sokcho were classified as potential acid-generating samples. This can be expected to affect the quality of aggregates when a large amount of aggregate is used in the future. Therefore, it is judged that these forest aggregates need to be managed when they are used. By predicting the occurrence of ARD through the acid-generating ability test, it is expected that economic losses that may occur in the future can be reduced, and it is judged that the problem of surrounding environmental pollution can be further alleviated.

• Research in Plant Disease
• /
• v.11 no.1
• /
• pp.16-20
• /
• 2005

Several time-course experiments were carried out to understand seasonal development of melanose on yuzu trees at koehung area, Jeonnam province, during May to October. The occurrence of dead twigs, known as a source of infection, was much more in older trees, and from June to August, mostly in July. In the experiment of pycnidia development on dead twigs seasonally collected, the number of developed pycnidia was highest on July-collected dead twigs especially with the diameter of 1.1~1.5 cm. In the collection survey of disseminated pycnidiospores, although the collected number of pycnidiospores was affected with amount of precipitation, the number of observed pycnidiospores in rainwater was relatively high from June to August, with highest in early August in 1997 and late July in 1998. In the inoculation tests on 3-year-old trees and fruits in natural condition, disease occurrences were mostly affected on twigs by inocula treatment in June, and on fruits by inocula treatment in July, respectively.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 2000.06a
• /
• pp.37-41
• /
• 2000

폐기물 소각시 발생되는 각종 유해가스 및 비산회재(fly ash)는 후처리 설비에 의해 배출허용기준치 이하로 처리된 후 대기 중으로 방출되도록 환경 규제되고 있다. 그러나 포집된 비산회재(fly ash) 및 노하부 배출재(bottom ash) 내에는 미 연소된 상태로 배출된 유해성 유기물질(다이옥신, 퓨란류 등)과 중금속 성분이 함유되어 있어 이들 소각잔류물(incineration residues)을 안정화나 무해화 처리 없이 단순 매립할 경우 강우에 의해 소각잔류물 내의 유해성분이 침출됨에 따라 토양이나 지하수 등에 2차 환경오염을 일으키게 된다. (중략)

• Textile Coloration and Finishing
• /
• v.7 no.2
• /
• pp.92-93
• /
• 1995

1970년도 후반까지만 하더라도 염료생산은 선진국형 산업으로만 생각하여 왔으나 인건비 상승, 환경처리비부담, 운성비 등의 부담으로 선직국의 염료생산공장들은 앞다투어 생산기지를 후진국으로 신설 또는 이전을 하게 되었다. 한편 생산량도 증가되어 수요에 비하여 공급과다로 지나친 판매경쟁이 일어나고 채산성도 나빠진 것이 현실이다. 이러한 나라들 중에는 제조기술의 미흡, 원가절감, 품질관리의 미숙 등으로 lot별 농도차이, 용해성불량, 염료중에서의 재응집, 飛散등의 문제로 염색공장에서 애로를 겪는 경우가 자주 발생하고 있다. 특히 염료의 비산 문제는 칭량원의 보건상 나쁜 영향을 미치게 되고 염색현장까지 염료입자가 날아가 피염물에 오염을 일으키기도 한다. 이러한 문제점을 해결하기 위하여서는 다각적으로 관리에 철저를 기하지 않으면 안된다.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2021.05a
• /
• pp.299-300
• /
• 2021

In this study, a questionnaire survey was conducted on the occurrence of fine dust at the construction site and the effectiveness of countermeasures. Based on the results of the survey, it is intended to be used as basic data for establishing a method to reduce fine dust in construction sites.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.06a
• /
• pp.210-211
• /
• 2020

In this study, a questionnaire survey on the occurrence status of fine dust in urban construction sites and the response level was conducted. Based on the results of the survey, it is intended to be used as basic data for establishing a method to reduce fine dust in construction sites.

• Korean Journal of Environment and Ecology
• /
• v.16 no.2
• /
• pp.141-148
• /
• 2002

This study was carried out to estimate the effect of forest fire on herb layer development and chemical properties of soil. The forest fire was in April 2000 in Pinus rigida(softwood) and Robinia pseudoacacia(hardwood) dominant forests at Gaejoksan, Daejeon. Vegetation studies were in the two communities and herb layer development study was in July using dominance of Dierssen. The coverage of herb layer was higher in the burned area than in the unburned area in the two study communities. There was no different herb layer species number between the burned and unburned areas, but there was different herb layer species number between the two communities. Soil samples were collected at 0～10cm and 10～20cm soil depths from the unburned and burned sites after 3 days and 8 months of forest fire. There was no forest floor in burned site, but unburned site has the forest floor of 1.5cm thick. There were no significant differences in soil organic matter, total N, available P, exchangeable K, Ca, Na, and Mg, and CEC, pH in all soil depth, between unburned and burned sites after 3 days of forest fire and between burned site after 3 days and 8 months of forest fire, except in organic matter in 10～20cm soil depth in hardwood sites and in exchangeable Ca in the 10～20cm soil depth, and in Mg in the two soil depths in hardwood sites. It seems to be that forest fire had not changed the chemical soil properties in this study.

• Journal of the Korean Society for Railway
• /
• v.12 no.1
• /
• pp.39-44
• /
• 2009

The ballast-flying, induced by strong underbody flow of high-speed train, can damage train underbody, wheel and even cause the safety problems. For this reason, a heighter is being used to prevent ballast-flying through underbody flow reduction. In this research, flow field around a heighter is numerically simulated.. And the parametric study of various heighter geometries is performed to find out more effective heighter shape. Through these numerical studies, the relation between the heighter shape and underbody flow is found out. Also new heighter shapes are numerically investigated and their performances of underbody flow reduction are verified.