• Journal of the Mineralogical Society of Korea
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• v.31 no.4
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• pp.287-293
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• 2018

Amorphous silica ($SiO_2$) silt grains were found in some soils of Korean Peninsula. Scanning electron microscopy of polished section of soils revealed ellipsoidal amorphous $SiO_2$ grains with numerous submicron pores concentrated in the interior. Their amorphous structure was confirmed by lattice imaging and electron diffraction under transmission electron microscope. Amorphous $SiO_2$ grains were not found in the eolian sediment of the Chinese loess plateau. Although the origin of the amorphous $SiO_2$ grain is uncertain, they are likely either phytolith or weathering product of volcanic ash. The amorphous $SiO_2$ silt grains are not useful as a tracer of long-range transport mineral dust in soils.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.413-414
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• 2001

실내공간에 존재하는 먼지입자를 제거하는데 적용되는 대표적인 방법들로는 섬유상 필터를 이용한 먼지입자 여과 기술과 전기집진기를 이용한 여과 기술이 있다. 섬유상 필터를 이용한 여과 기술은 입자의 관성충돌(inertial impaction), 차단(interception) 및 확산(diffusion) 메카니즘을 이용한 기술로써, 입자포집 효율이 아주 우수한 반면 압력손실이 큰 단점이 있다. 이러한 단점을 개선하기 위하여 개발된 필터로써 정전부착(electrostatic deposition) 메카니즘을 이용한 정전여과필터(electret filter)라고 것이 있는데, 이것은 섬유 자체에 정전 하전을 주입시킨 특수한 필터이다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.247-248
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• 2003

우리 나라의 도시ㆍ산업단지 지역의 대기오염은 심각한 수준으로, 특히 미세먼지로 인한 대기오염은 스모그 등 심미적인 문제뿐만 아니라 호흡성 분진으로 인한 건강 위해성 측면에서 철저한 오염원 관리가 필요하다. 현재 우리 나라의 먼지 배출량을 보면 비산먼지의 배출량이 연소과정에서 발생되는 미세먼지보다도 큰 것으로 추정되며, 특히 이 중에서 자동차의 도로주행시 발생되는 먼지가 비산먼지 발생량 중 90 %이상을 차지하고 있는 것으로 추정된다(국립환경연구원, 2002). 차량운행으로 인하여 포장도로에서 발생하는 비산먼지 배출량은 도로 표면의 단위면적 당 silt(75$\mu\textrm{m}$이하의 입자)량, 즉 silt loading에 의해 좌우되는데 silt loading은 도시ㆍ산업단지의 체계적인 개발계획 및 대기질 관리정책을 수립에 없어서는 안 될 중요한 자료이다. (중략)

• Journal of the Korean Magnetics Society
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• v.10 no.6
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• pp.310-317
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• 2000

With use of (G)MR head, thermal asperity (TA) has been a big concern in drive industry. In this study, we investigated several factors of heads and disks which affects the TA sensitivity of the drive. TA experiments were conducted by introducing the particles on the drives using a particle injection chamber. It was found that the slider ABS shape can help to reduce TA or contamination in the head/media interface. However, TA sensitivity of the drive mainly depend on the intrinsic property of (G)MR sensor. GMR head is much less sensitive to TA compared with MR head. However, in case that the same bias current was applied for both of MR and GMR head, TA sensitivity of GMR head became almost identical to that of MR head. Therefore it was found that the bias current is a dominant factor in determining TA sensitivity of the head. TA sensitivity of different types of disks was also studied. The scratch resistance of the carbon overcoat layer is the one of the main factors which influence TA rejection capability of the disks.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.493-494
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• 2003

본 연구에서는 전기집진 기술과 여과집진 기술의 조합에 의한 먼지입자의 포집성능 상승효과를 최대한 높일 수 있는 먼지부하 저감형 하이브리드 집진장치(Hi-Filter)를 개발하기 위한 연구의 일환으로 파일럿 규모의 실험장치에서 운전 조건을 변화시키면서 장시간 실험을 통해 집진성능 특성 변화를 고찰한다. (중략)

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.05a
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• pp.223-226
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• 2002

본 연구에서는 전기집진 기술과 여과집진 기술의 조합에 의한 먼지입자의 포집성능 상승효과를 최대한 높일 수 있는 먼지부하 저감형 하이브리드 집진장치(Hi-Filter)를 개발하기 위해 실험실 규모의 장치를 이용한 실험을 통하여 장치의 최적 형상을 결정하고 그 성능을 검증하였다.(중략)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6610-6617
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• 2013

This study examined the current and future Indoor Air Quality (IAQ) control device markets and analyzed the recent studies on indoor air pollutantr emoval to develop a new technology for fine dust control. Currently, the mechanical filter technique occupies the bulk of the IAQ control market but the electronic technique is emerging as an alternative to control fine dust efficiently. Among the gaseous VOCs and fine dust particles contaminating the indoor air quality, fine dust particles are more problematic because they threaten human health by penetrating deep into the body and producing secondary contaminants by chemical reaction with VOCs. The electronic IAQ control device using dielectrophoretic and electrostatic forces is a good option for public spaces where many people pass, and at the same time, it needs to consider temperature, humidity, and the particle properties of specific areas to highlight the control efficiency. Electronic-related technology is expected to be used widely in many public/private spaces wherever a dust-free environment is required.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.185-186
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• 2001

미세입자의 배출원을 추정하기 위해서는 수용지점에 영향을 미칠 수 있는 배출원의 화학적 특성에 관한 정보를 필요로 한다. 수용모델(chemical mass balance model, CMB)의 경우, 모델수행에 필요한 정보는 각각의 배출원에서 배출되는 입자의 화학적 구성성분특성을 파악하는 것이 가장 중요하다(Waton et al., 1984; U. S. EPA, 1987; 강병욱 등, 2000) 이러한 배출원으로는 각종 산업배출원, 자동차, 토양, 도로 비산먼지 등 지역의 특성에 따라서 다양한 배출원들이 대상이 될 수 있다. (중략)

• Journal of the Korean Chemical Society
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• v.58 no.3
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• pp.267-276
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• 2014

The collection of $PM_{10}$ and $PM_{2.5}$ fine particulate matter samples was made at the 1100 m site of Mt. Halla of Jeju Island, located at the atmospheric boundary layer (ABL) of background area, during the fall of 2012. Their ionic and elemental species were analyzed, in order to investigate the chemical compositions and size distribution characteristics. In $PM_{2.5}$ fine particles ($d_p$ < $2.5{\mu}m$), the concentrations of the secondary formed nss-$SO{_4}^{2-}$, $NH_4{^+}$ and $NO_3{^-}$ species were 4.84, 1.98, and $1.27{\mu}g/m^3$, respectively, showing 58.2% of the total $PM_{2.5}$ mass. On the other hand, their concentrations in $PM_{10-2.5}$ coarse particles (2.5 < $d_p$ < $10{\mu}m$) were 0.63, 0.21 and $1.10{\mu}g/m^3$, respectively, occupying 22.8% of the total $PM_{10-2.5}$ mass. The comparative study of size distribution has resulted that $NH_4{^+}$, nss-$SO{_4}^{2-}$, $K^+$ and $CH_3COO^-$ are mostly existed in fine particles, and $NO_3{^-}$ is distributed in both fine and coarse particles, but $Na^+$, $Cl^-$, $Mg^{2+}$ and nss-$Ca^{2+}$ are rich in coarse particle mode.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.4
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• pp.221-228
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• 2017

We proposed a novel method to remove PM2.5 dusts without HEPA filters aiming at applications in kitchens or enclosed work spaces generating PM2.5 at high concentrations. Many workers are exposed to PM2.5 owing to lack of air purification because the high replacement costs of HEPA filters make their application impractical. A key idea is to use the condensational growth of nanoparticles. Once particles grow to the size of a few micrometers, it is much easier to remove them because of their increased inertia. We developed and tested a prototype consisting of an air saturator (equipped with water spray nozzles), a condenser in which humid air was cooled down to make the particles grow, and a multi-impactor assembly for collecting the grown particles.