• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.97-98
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• 2003

나노/서브마이크론 크기의 입자는 최근 유해 입자상 물질 제거 및 오염 제어나 물질 제조 등의 분야에서 관심이 높아지고 있다. 보통 환경 입자상 물질로 불리는 0.1~l $\mu\textrm{m}$ 범위의 서브마이크론 입자는 자동차, 공장, 발전소, 소각로 등의 연소 과정에서 발생되어 상당량이 대기로 배출되는데, 인체에 유입되면 호흡기 장애나 암을 유발하는 등의 나쁜 영향을 미친다. 특히, 관성력과 확산력에 의한 영향이 적고 하전 입자의 전기적인 이동도도 낮기 때문에 집진장치나 공기청정장치에서 집진효율이 가장 낮은 크기 범위이다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.325-327
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• 2000

본 연구에서는 한반도의 청정지역인 제주도 고산과 한라산 1100 고지에서의 입자상 물질을 분석하였다. 입자상 물질을 분석하는 방법 중에 EPMA(Electron Probe X-ray Microanalysis)를 이용한 단일 입자 분석법(Single Particle Analysis)은 개개 입자의 형상과 크기 그리고 화학 조성에 대한 정보를 동시에 제공하기 때문에 개개 입자의 생성, 이동, 반응성, 소멸 그리고 환경에의 영향에 대한 자세한 정보를 얻을 수 있다. (중략)

• Journal of the Korean Geotechnical Society
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• v.34 no.2
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• pp.19-32
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• 2018

During the process of gas hydrate extraction in the deep seabed, fine diatom particle migration occurs, which causes the seabed slope failure and the productivity deterioration of the gas hydrate. Therefore, a study related with the changes of the ground characteristics due to the fine particle migration is required. The objective of this study is to investigate the change of hydraulic properties of sand due to the migration of fine diatom particle in sandy soils. In order to simulate the sediments of the Ulleung basin gas hydrate in the East Sea, fifteen sand-diatom mixtures that have different diatom volume fractions (DVF) are prepared. During the falling head permeability tests, the coefficients of permeability are measured according to the DVF. In addition, for the simulation of the fine diatom particle migration, constant head permeability tests are conducted by applying the hydraulic pressures of 3 kPa, 6kPa, and 9 kPa on a specimen composed of two layers: a specimen with 50% DVF in upper layer and a specimen with 0% DVF in lower layer. Furthermore, the coefficient of permeability and the electrical resistivity of the migration zone are measured during the constant head permeability test. The falling head permeability tests show that the coefficient of permeability decreases as the DVF of the specimen increases. In addition, the gradient of the coefficient of permeability curve decreases in the DVF range of 10%~50% compared with that of 0%~10%, and increases above 50% in DVF. The result of constant head permeability tests shows that the coefficient of permeability decreases and electrical resistivity increases in the migration zone due to the fine diatom particle migration. This study demonstrates that fine diatom particle migration reduces the permeability of the soils and the behavior of the migration zone due to the fine diatom particle migration may be estimated based on the reversal relationship between the coefficient of permeability and the electrical resistivity.

• Journal of Korea Water Resources Association
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• v.56 no.2
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• pp.125-137
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• 2023

In marine environments, plastics have become more abundant due to increasing plastic use. Especially, in coastal regions, particles may remain for a long time, and they interact with flows, wind, sand and human activities. This study aimed thus to observe how plastic debris interacts with and escape from sediments. A series of experiments were conducted in order to gain a better understanding of particle release from coastal sediments into water body. An oscillating water tunnel was built for the experiments, and used to generate oscillatory flows of relatively high Reynolds number and induce sediment transport. Spherical plastic particles of three different sizes was used in lieu of plastic debris in environments. It was observed that release of the particles was directly related to change of bedform, which is in turn determined by the flow condition. Also smaller particles tend to escape the sediment more readily. Critical values for dimensionless parameters are proposed.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.215-216
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• 2000

대기 중에 존재하는 입자의 생성 및 변화를 모델링 하는데 있어서 가장 중요한 요소는 응축/휘발 (condensation/evaporation)과 같은 기체/입자간의 상호 과정을 어떻게 모사 하느냐 하는 것이다. 일반적으로 지금까지의 연구는 입자와 가스상의 농도가 순간적으로 평형을 이룬다고 가정해 왔으나 실제 대기상의 입자는 비 평형(non-equilibrium)상태의 응축/휘발 과정을 따르는 것으로 알려져 왔다. (중략)

• Proceedings of the KAIS Fall Conference
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• 2008.11a
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• pp.167-169
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• 2008

본 논문에서는 대전입자형 디스플레이에 인가된 펄스에 따라 운동하는 대전입자(토너)를 광학적인 관측과 전기적인 측면에서 관찰하였으며, 증폭되는 펄스에 따라 변화하는 대전입자의 응답속도를 측정하여 대전입자의 구동특성을 분석하였다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.85-86
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• 2002

제주도 고산은 우리나라의 대표적인 배경농도지역으로 동북아시아에서 대기오염물질의 장거리이동 특성을 규명하는데 중요한 지역이다. 이 발표에서는 1992년부터 2001년까지 고산에서 측정한 입자상 무기이온 성분의 농도를 통하여 입자 특성을 파악하고자 하였다. (중략)

• Nuclear Engineering and Technology
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• v.27 no.2
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• pp.176-188
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• 1995

A particle tracking scheme was developed in order to model radionuclide transport through a tortuous flow Held in a rock fracture. The particle tacking method may be used effectively in a heterogeneous flow field such as rock fracture. The parallel plate representation of the single fracture fails to recognize the spatial heterogeneity in the fracture aperture and thus seems inadequate in describing fluid movement through a real fracture. The heterogeneous flow field une modeled by a variable aperture channel model after characterizing aperture distribution by a hydraulic test. To support the validation of radionuclide transport models, a radionuclide migration experiment was performed in a natural fracture of granite. $^3$$H_2O$ and $^{131}$ I are used as tracers. Simulated results were in agreement with experimental result and therefore support the validity of the transport model. Residence time distributions display multipeak curves caused by the fast arrival of solutes traveling along preferential fracture channels and by the much slower arrival of solutes following tortous routes through the fracture. Results from the modelling of the transport of nonsorbing tracer through the fracture show that diffusion into the interconnected pore space in the rock mass has a significant effect on retardation.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.309-310
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• 2003

입자상물질에 대한 연구는 광역적인 대기 오염정도의 평가 및 오염물질의 이동에 대한 유용한 정보를 제공해 주므로 이와 같은 오염원의 크기에 대한 배경농도를 파악하는 것이 무엇보다 중요하다. 또한 입자상물질은 대기중에서 기류를 타고 이동할 수 있기 때문에 오염농도 변화는 지역적인 영향을 받는 대도시 지역보다 오염원으로부터 격리된 청정지역에서의 측정이 필요하다(신혜정 등, 2002). 본 연구에서는 국내 배경농도 측정지점 중 하나인 강화에서 2000년부터 2002년까지 측정한 입자상 물질의 농도 특성을 파악하고자 한다. (중략)

• Journal of the Korea Convergence Society
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• v.11 no.3
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• pp.53-59
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• 2020

Initial response is important in marine oil spills, such as the Hebei Spirit oil spill, but it is very difficult to predict the movement of oil out of the ocean, where there are many variables. In order to solve this problem, the forecasting of oil spill has been carried out by expanding the particle prediction, which is an existing study that studies the movement of floats on the sea using the data of the float. In the ocean data format HDF5, the current and wind velocity data at a specific location were extracted using bilinear interpolation, and then the movement of numerous points was predicted by particles and the results were visualized using polygons and heat maps. In addition, we propose a spill oil particle matching algorithm to compensate for the lack of data and the difference between the spilled oil and movement. The spilled oil particle matching algorithm is an algorithm that tracks the movement of particles by granulating the appearance of surface oil spilled oil. The problem was segmented using principal component analysis and matched using genetic algorithm to the point where the variance of travel distance of effluent oil is minimized. As a result of verifying the effluent oil visualization data, it was confirmed that the particle matching algorithm using principal component analysis and genetic algorithm showed the best performance, and the mean data error was 3.2%.