• 한국산업보건학회지
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• 제21권3호
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• pp.177-183
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• 2011

Occupational exposure to silicon carbide dust of manufacturing industries has seldom been evaluated in Korea. Accordingly, we evaluated various silicon carbide dust concentrations in the breathing zone of workers between May 2010 and July 2010. To compare silicon carbide dust concentrations, three dust samplers including the Institute of Occupational Medicine (IOM) sampler, 37mm cassette sampler, and Aluminum cyclone sampler were used. A total of 5 manufacturing industries producing abrasive and refractory materials using silicon carbide were investigated. The geometric mean concentrations were 2.04, 0.97, and $0.48mg/m^3$ in inhalable, total and respirable silicon carbide dust, respectively. The geometric mean concentrations of silicon carbide in abrasive material manufacturing industries were slightly higher than that of refractory manufacturing industries, and finishing operations were higher than that of other operations. It was found that the results of exposure assessment in airborne dust at manufacturing industries using silicon carbide in Korea showed exceeding rate to American Conference of Governmental Industrial Hygienists Threshold Limit Value ($3mg/m^3$) was 10% in respirable dust samples. Therefore, with the consideration of the close relationship between smaller dust size and the occurrence of occupational respiratory diseases, it is suggested to promulgate the new occupational exposure limit for respirable silicon carbide dust.

• 통합자연과학논문집
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• 제4권1호
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• pp.7-10
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• 2011

Various types of smart dust based on photonic crystal exhibiting unique reflectivity were successfully obtained by an electrochemical etching of silicon wafer using square wave currents. Smart dust containing Bragg structure obtained from the sonication of DBR porous silicon film in solution retained its optical reflectivity. Field emission scanning electron micrograph (FE-SEM) was used to measure the size of optically encoded smart dust and its size can be tuned from few hundred nanometers to few microns depending on the duration of sonication. Optical characteristics of smart dust were used to investigate a possible applications such as chemical sensors.

• 한국재난정보학회 논문집
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• 제18권3호
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• pp.478-486
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• 2022

연구목적: 건설현장에서 작업환경측정을 하고 있으나 노출되고 있는 유해인자를 세분화하여 작업환경 측정을 하지 않고 공정별 대표적으로 노출되는 소음, 진동 등 몇 가지만 실시하고 있다. 이에 건설현장에서 가장 많이 노출되는 산화규소분진의 유해성과 현재 건설현장에서 하고있는 개선대책의 보완점을 찾고자 한다. 연구방법: 안전보건공단과 산업보건협회에서 발행하는 실태조사 보고서 및 작업환경측정 기관의 자료를 활용하여 현황을 분석하였고 산업안전보건법의 작업환경측정에 관한 규칙과 비교분석 하였다. 연구결과: 산화규소분진의 유해성을 파악하고 개선책을 보완도출하였다. 결론: 건설현장의 산화규소분진의 유해성을 도출하고 이에 따른 개선대책을 제시함으로써 현장에서 적극적으로 적용한다면 산화규소분진에 대한 직업병을 줄일 수 있을 것으로 기대된다.

• 자원리싸이클링
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• 제21권3호
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• pp.21-27
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• 2012

이전의 연구에서는 $Mn_3O_4$ 분진으로부터 고순도 훼로망간를 얻기 위해, Al 테르밋법이 검토되었다. 그 결과는 Mn 함유율이 약 93% 이상이고, KS D3712 규격 이하의 낮은 C, P, S의 불순물을 함유한 고순도 페로망간을 얻을 수 있음 보여주었다. 본 연구에서는 제조 코스트가 Al 분말보다 저렴한 Si 분말이 $Mn_3O_4$ 분진의 테르밋 반응법의 환원제로 검토되었다. 그 결과 환원제로 Si 분말을 단독으로 첨가할 경우는 착화가 불안정하여 테르밋 반응이 일어나지 않았으나, 환원제로 Si 분말과 Al 분말을 동시에 첨가할 경우는 C, P, S의 불순물 함유율이 매우 낮은 고순도 페로망간을 얻을 수 있었다.

• 통합자연과학논문집
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• 제3권2호
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• pp.84-88
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• 2010

Photonic crystals containing rugate structures from a single crystalline silicon wafer was obtained by using a sinoidal alternating current during an electrochemical etch procedure. Photonic crystals were isolated from the silicon substrate by applying an electropolishing current and were then made into particles by using an ultrasonic fracture in an ethanol solution to give a smart dust. Smart dusts exhibited their unique nanostructures and optical characteristics. They exhibited sharp photonic band gaps in the optical reflectivity spectrum. The size of smart dust obtained was in the range of 10-20 nm.

• 한국대기환경학회지
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• 제28권1호
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• pp.86-93
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• 2012

We present a retrieval method to obtain dust backscatter coefficient from the mixed Asian dust and pollutant layer. In the present study, vertically resolved quartz (silicon dioxide, silica) concentration was calculated using Raman scattering signals from quartz at 546 nm. Dust concentration was obtained based on typical mass percentage of quartz in Asian dust. The highest value of dust concentration at 3.7 km in March 21, 2010 was 22.3 and 10.9 ${\mu}gm^{-3}$ according to the quartz percentage in Asian dust as 65 and 30% based on literature survey, respectively. OPAC (Optical Properties of Aerosol and Clouds) simulations were conducted to calculate dust backscatter coefficient. The retrieved dust concentration was used as an input parameter for the OPAC calculations. Utilization of quartz Raman channel in Lidar measurements is considered useful for distinguishing optical properties of dust and nondust aerosol in the mixing state of Asian dust.

• 한국대기환경학회지
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• 제27권3호
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• pp.326-336
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• 2011

The Light Detection and Ranging (Lidar) observation provides a specific knowledge of the temporal and vertical distribution and the optical properties of the aerosols. Unlike typical Mie scattering Lidars, which can measure backscattering and depolarization, the Raman Lidar can measure the quartz signal at the ultra violet (360 nm) and the visible (546 nm) wavelengths. In this work, we developed a method for estimating mineral quartz concentration immersed in Asian dust using Raman scattering of quartz (silicon dioxide, silica). During the Asian dust period of March 15, 16, and 21 in 2010, Raman lidar measurements detected the presence of quartz, and successfully showed the vertical profile of the dust concentrations. The satellite observations such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) confirmed spatial distribution of Asian dust. This approach will be useful for characterizing the quartz dominated in the atmospheric aerosols and the investigations of mineral dust. It will be especially applicable for distinguishing the dust and non-dust aerosols in studies on the mixing state of Asian aerosols. Additionally, the presented method combined with satellite observations is enable qualitative and quantitative monitoring for Asian dust.

• 한국대기환경학회지
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• 제19권4호
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• pp.415-425
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• 2003

A single particle analysis, called low-Z electron probe X-ray microanalysis was applied to characterize the atmospheric aerosols collected during Asian Dust storm events in the year of 2000 and 2001. Most frequently encountered chemical species were the soil-originated species such as aluminosilicates, silicon dioxide, and calcium carbonate. Also various species such as carbon -rich, organics, sea salts, and some reacted calcium carbonate were identified. The observation of internally mixed particles oi calcium carbonate, calcium nitrate and/or calcium sulfate shows the occurrence of the heterogeneous reaction between Asian Dust particles and NO$_{x}$ and/or SO$_{x}$ species in the atmosphere.ere.

• 한국결정성장학회지
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• 제16권2호
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• pp.76-81
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• 2006

중금속 이온의 용출거동은 콜로이드/계면 성질에 의존하는데, 이를 알아보기 위해 ICP와 SEM 분석을 하였다. 전기로 제강분진에 포함된 중금속은 '양쪽성 금속'으로 pH 10에서 중금속이 가장 적게 용출되는 것을 알 수 있었고 pH 8보다 pH 12에서 중금속 이온이 상당량 용출되어 나왔다. 그리고 전기로 제강분진에 점토를 첨가함으로써 중금속 이온의 용출이 감소하는 것을 알 수 있었다. 특히 pH 12의 경우에 pH 8에 비해서 중금속 이온의 용출이 큰 폭으로 감소하였으며 콜로이드계면 성질 관찰 결과, 점토의 경우 pH 12에서 점토에서 녹아나온 Si 수화물이 점토 입자표면을 둘러싸고 있음을 관찰할 수 있었다. 전기로 제강분진과 점토의 혼합 슬러리에서 pH 8의 경우보다 pH 12에서 중금속 이온의 농도가 크게 감소한 것은 PSHP의 형성에 의한 것으로 사료된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.939-940
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• 2010