• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1313-1314
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• 2006

For improvement of wear resistance property of atmospheric thermal plasma sprayed molybdenum (Mo) coating, diamond deposition on the atmospheric plasma sprayed molybdenum coating by the combustion flame chemical vapor deposition (CFCVD) has been operated. In this study, to diminish the thermal damage of the substrate during operation, a thermal insulator was equipped between substrate and water-cooled substrate holder. Consequently, diamond particles could be created on the Mo coating without fracture and peeling off. From these results, it was found that this process had a high potential in order to improve wear resistance of thermal sprayed coating.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.4
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• pp.16-41
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• 2020

Geospatial input setting to represent the reality of spatial distribution or quantitative property within model has become a major interest in earth system simulation. Many studies showed the variation of grid resolution could lead to drastic changes of spatial model results because of insufficient surface property estimations. Hence, in this paper, the authors proposed Monte Carlo Integration (MCI) to apply spatial probability (SP) in a spatial-sampling framework using a three-dimensional point cloud (3DPC) to keep the optimized spatial distribution and area/volume property of buildings in urban area. Three different decision rule based building identification results were compared : SP threshold, cell size, and 3DPC density. Results shows the identified building area property tend to increase according to the spatial sampling grid area enlargement. Hence, areal building property manipulation in the sampling frameworks by using decision rules is strongly recommended to increase reliability of geospatial modeling and analysis results. Proposed method will support the modeling needs to keep quantitative building properties in both finer and coarser grids.

• Journal of the Korean Professional Engineers Association
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• v.41 no.4
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• pp.43-46
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• 2008

The extreme weather events have increased around the world this century. One of the main reasons of frequent occurrence is the change of atmospheric circulation by El nino. also Korea Peninsular is not exception. The 97 % of death toll and 89 % of property loss of total are related with extreme-weather events for the last 10 years. for example the heavy rainfall (1998-4999) and Typhoon Rusa and Mamie. In spite of the percent of death toll by extreme-weather disaster is increasing and the total population is growing. but the number of death toll from natural disasters is decreasing. It shows that the loss of property and life can be minimize by preparing the proper disaster prevention measures. There are several preparations to reduce the damage by extreme-weather events: Public facilities have overall check up, to recognize the weather alert, the awareness of the escape route and the art of measures

• 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)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.81-82
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• 2003

제주도 서단의 고산 상층기상대는 한반도와 중국대륙, 그리고 대양으로부터의 물질이동의 중간 경로에 위치한 지리적인 요인에 의하여, 동아시아 지역의 대기오염물질의 특성을 파악하기 유리한 장소라 할 수 있다. 2001년부터 계절에 따라 이 지역에서 Micro Pulse Lidar(MPL)를 이용한 에어러솔 관측이 수행되었고, sunphotometer 관측도 병행되어 에어러솔의 공간분포 및 광학적 특성을 파악할 수 있었다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2007.10a
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• pp.414-415
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• 2007

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.355-356
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• 1999

대기오염물질의 침적에 의해 호소나 연안해수의 조성이 변화하여 수서 생태계에 영향을 미칠 가능성에 대해서는 여러 논의가 있었다. 특히 질소화합물의 대기로부터의 유입에 의한 부영양화는 적조 등의 현상을 일으켜, 연안 생태계에 큰 영향을 미칠 수 있다. 따라서, 연안에서 침적되는 대기오염물질의 양을 추산하기 위해 에어로솔상의 이온성분을 측정하는 것은 침적 현상이해에 매우 중요하다.(중략)

• Journal of the Korean institute of surface engineering
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• v.54 no.6
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• pp.340-347
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• 2021

Among various metal oxide semiconductors, ZnO has an excellent electrical, optical properties with a wide bandgap of 3.3 eV. It can be applied as a photocatalytic material due to its high absorption rate along with physical and chemical stability to UV light. In addition, it is important to control the morphology of ZnO because the size and shape of the ZnO make difference in physical properties. In this paper, we demonstrate synthesis of size-controlled ZnO tetrapods using an atmospheric pressure plasma system. A micro-sized Zn spherical powder was continuously introduced in the plume of the atmospheric plasma jet ignited with mixture of oxygen and nitrogen. The effect of plasma power and collection sites on ZnO nanostructure was investigated. After the plasma discharge for 10 min, the produced materials deposited inside the 60-cm-long quartz tube were obtained with respect to the distance from the plume. According to the SEM analysis, all the synthesized nanoparticles were found to be ZnO tetrapods ranging from 100 to 600-nm-diameter depending on both applied power and collection site. The photocatalytic efficiency was evaluated by color change of methylene blue solution using UV-Vis spectroscopy. The photocatalytic activity increased with the increase of (101) and (100) plane in ZnO tetrapods, which is caused by enhanced chemical effects of plasma process.

• Membrane Journal
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• v.34 no.1
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• pp.30-37
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• 2024

As a promising method to address global water scarcity, sorbent-assisted water harvesting from air has shown great potential to deliver drinking water for inlands lacking traditional water sources. In this article, the recent studies of using metal-organic frameworks (MOFs) as sorbents to harvest atmospheric water will be introduced. Compared to the other sorbent materials such as zeolites or silica-based materials, MOFs have shown prospective properties such as the water isotherm inflection points as low as ~10%, which are suitable for harvesting water at dry regions. Due to this property, recently, MOFs have been extensively adopted to develop practical water harvesting devices that can harvest water. Since atmospheric water is accessible anywhere and anytime in the world, this technology is expected to open a new avenue in terms of securing safe water for the future.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.9
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• pp.528-533
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• 2016

One of ways for effectively maintaining asbestos buildings is to select asbestos buildings to be removed firstly by manufacturing and analyzing asbestos map of various topics. Thus, in this study we manufactured asbestos map of various topics for the effective management of asbestos buildings owned by Seoul using QGIS (Quantum Geographic Information System). To select asbestos buildings likely to cause asbestos scattering problem and exposure into the air, we comprehensively took into consideration various topics such as asbestos buildings density, asbestos-area ratio, asbestos buildings distribution considering the population, first removal object, risk assessment, elapsed year. As described in this study, using the GIS may be utilized as a method for selecting asbestos buildings to be removed firstly as well as distribution of asbestos buildings. In the future, it is necessary to make assessment criteria considering diversification of property value in GIS such as the characteristics of the living environment around the asbestos buildings. This is expected to be utilized to manage the vulnerable region to asbestos exposure.