• 한국결정성장학회지
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• 제16권5호
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• pp.227-234
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• 2006

제강분진(EAF dust, 이하 더스트)이 첨가된 규산염계 유리 프리트를 용융하여 유리 시편을 제조하고, 이를 열처리하여 결정화 시킨 후 표면 및 내부의 미세구조를 관찰하였다. 제조된 유리의 DTA 분석결과 결정화온도($T_c$)는 $850^{\circ}C$ 부근이었으며 이로부터 열처리 온도를 $950^{\circ}C$로 정하였다. XRD 분석결과 더스트가 50wt% 들어간 유리시편은 비정질 상태였으나 70wt% 들어간 유리시편은 spinel 결정상이 나타났다. 결정화유리시편은 spinel 및 willemite 결정상이 함께 나타나며 더스트의 첨가량이 증가할수록 willemite 결정상이 증가하였다. 더스트의 함유량이 50wt%인 유리시편의 경우 연마된 절단면이 거울 표면같이 매끄러운 상태였으나 70wt% 첨가된 경우에는 유리질의 모상(glass matrix)내에 최대 10mm 크기의 spinel 결정상이 존재하였다. 결정화유리시편의 경우에는 자유표면에 $2{\sim}5{\mu}m$ 크기의 ZnO 결정입자들이 생성되었고, 내부에는 유리상, spinel 그리고 willemite 결정상이 혼재하였다. 더스트가 50wt% 첨가된 유리는 결정입자가 존재하지 않았으나 70wt% 첨가된 유리시편에는 14%의 결정이 존재하였다. 더스트가 50 및 70wt% 첨가된 결정화유리시편의 결정화도는 각각 19 및 43% 이었다. 결정화 전후 시편들을 TCLP 용액에 18시간 담근 후 SEM을 통하여 미세구조를 관찰했을 때 유리시편에는 균열이 발생하였으나, 결정화유리시편의 경우 침식흔적은 나타났으나 균열은 존재하지 않았다.

• 천문학회지
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• 제37권4호
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• pp.289-294
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• 2004

The main sources of interstellar dust are believed to be dust envelopes around AGB stars. The outflowing envelopes around the long period pulsating variables are very suitable place for massive dust formation. Oxygen-rich silicate dust grains or carbon-rich dust grains form in the envelopes around AGB stars depending on the chemical composition of the stellar surface. The dust grains expelled from AGB stars get mixed up and go through some physical and chemical changes in interstellar medium. There are similarities and differences between interstellar dust and dust grains in AGB stars. The mass cycle in the Galaxy may be best manifested by the fact that the dust grains at various regions have many similarities and understandable differences.

• 조명전기설비학회논문지
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• 제21권8호
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• pp.129-135
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• 2007

환경오염이 심한 분진 발생지역에서는 전기 사고가 자주 발생하기 때문에 전기설비에 대한 유지관리와 예방에 대한 연구가 필요하다. 특히 외부에 전기절연물이 장기간 노출되면, 쉽게 분진이 축적되고 수분, 습기 등에 의한 누설전류의 발생으로 전기사고에 이르게 된다. 따라서 본 연구에서는 분진, 염수 등에 의한 전기설비 절연재료 표면변화와 표면 누설전류를 측정하였다. 측정결과로부터 베이클라이트의 표면이 다른 재료보다 염수에 대한 영향이 심하였다. 또한 베이클라이트 표면 누설전류는 반복되는 염수 오염에 의해 증가하고 재료표면은 미소아크가 발생하고 탄화되었다. 따라서 절연물에서의 누설전류를 억제하기 위해서는 재료의 형태 및 표면 코팅 등이 변화가 필요하다.

• Corrosion Science and Technology
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• 제5권1호
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• pp.27-32
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• 2006

One of the critical issues in the coating specification is the allowable limit of surface contaminant(s) - such as soluble salt(s), grit dust, and rust - after grit blasting. Yet, there is no universally accepted data supporting the relationship between the long-term coating performance and the amount of various surface contaminants allowed after grit blasting. In this study, it was attempted to prepare epoxy coatings applied on grit-blasted steel substrate dosed with controlled amount of surface contaminants - such as soluble salt(s), grit dust, and rust. Then, coating samples were subjected to 4,200 hours of cyclic test(NORSOK M-501), which were then evaluated in terms of resistance to rust creepage, blistering, chalking, rusting, cracking and adhesion strength. Additional investigations on the possible damage at the paint/steel interface were carried out using an Electrochemical Impedance Spectroscopy(EIS) and observations of under-film-corrosion. Test results suggested that the current industrial specifications were well matched with the allowable degree of rust, whereas the allowable amount of soluble salt and grit dust after grit blasting showed a certain deviation from the specifications currently employed for fabrication of marine vessels and offshore facilities.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.65.1-65.1
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• 2013

Icy dust particles in interstellar clouds are considered to play a catalytic role in molecular evolution in space. Atoms and simple molecules constituting the ice mantles of dust particles may be transformed into more complex molecules under the irradiation of UV and cosmic rays. This seminar will present our recent study results for chemistry of ice surfaces, with the emphases on the mechanistic features of elementary reactions and the implications for interstellar molecular evolution. The types of reactions studied include molecule diffusion in ice, proton and hydroxide transfers, and some UV-induced reactions wih astrobiological relevance.

• 대기
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• 제22권2호
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• pp.245-257
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• 2012

The Asian dust (Hwangsa) forecasting model, Asian Dust Aerosol Model (ADAM) has been modified by using satelliate monitoring of surface vegetation, which enables to simulate dusts occuring not only in springtime but also for all-year-round period. Coupled with the Unified Model (UM), the operational weather forecasting model at KMA, UM-ADAM2 was implemented for operational dust forecasting since 2010, with an aid of development of Meteorology-Chemistry Interface Processor (MCIP) for usage UM. The performance analysis of the ADAM2 forecast was conducted with $PM_{10}$ concentrations observed at monitoring sites in the source regions in China and the downstream regions of Korea from March to December in 2010. It was found that the UM-ADAM2 model was able to simulate quite well Hwangsa events observed in spring and wintertime over Korea. In the downstream region of Korea, the starting and ending times of dust events were well-simulated, although the surface $PM_{10}$ concentration was slightly underestimated for some dust events. The general negative bias less than $35{\mu}g\;m^{3}$ in $PM_{10}$ is found and it is likely to be due to other fine aerosol species which is not considered in ADAM2. It is found that the correlation between observed and forecasted $PM_{10}$ concentration increases as forecasting time approaches, showing stably high correlation about 0.7 within 36 hr in forecasting time. This suggests the possibility that there is potential for the UM-ADAM2 model to be used as an operational Asian dust forecast model.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.158-161
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• 2001

A new type baghouse with tangential inlet and inner tube was developed and it's performances were evaluated. Experiments with variable shapes of inner tube were performed to suggest an optimum shape of inner tube which might decrease the dust loading onto bag filter surface and the amount of reentrained particles by internal gas flow. The dust loading was lower when inner tubes parallel to outer casing exist. When an inner tube covering around the lower portion of bag filters was used, the dust particles detached from the filter surface by cleaning process were reentraind by internal recirculating gas flow.

• 한국대기환경학회지
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• 제20권3호
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• pp.371-380
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• 2004

In the dust separation by using porous filter media, the structure of dust layer deposited on the filter surface of filter medium directly affects the effective filtration. The present study has investigated the specific resistance (K$_2$') of the dust layer and its porosity ($\varepsilon$$_{c}$) for three different filters; FA composite filter, metal fiber filter and stainless filter. The specific resistance (K$_2$') increased and at the same time the cake porosity ($\varepsilon$$_{c}$) decreased with the increase of filtration velocity, possibly due to the compressible effect of dust layer. However, under the low dust concentration, subsequent dust particles would block the open channels through the layer resulting in high specific resistance of the layer. The FA composite filter among three filters was shown to be the most effective filter for dust cake filtration at low filtration velocities less than 0.1 m/s for an approximate dust concentration of 5 g/㎥.

• 한국안전학회지
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• 제18권4호
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• pp.85-91
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• 2003

In this study, We have investigated leaching characteristics of heavy metals for recycled plastic composites containing EAF(Electric Arc Furnace) dust & EAF slag. EAF dust & EAF slag used that is generated in the 3 steel-making compaines in domestic. The physical and chemical properties of EAF dust & slag was examined by measuring specific surface area. porosity, oil absorption test and chemical wetting analysis etc. Results of total analysis indicated that EAF dust, slag contained significant amount of hazardous metals such as Cu, Pb, Cd and Cr. But, In the leaching test of the recycled plastic composites containing EAF dust, slag by Korean Standard Leaching Procedure, composites shows much lower leaching concentration of heavy metals. It was concluded that the recycled plastic composites containing EAF dust, slag showed good physical and chemical characteristics. This means that the EAF dust, slag can be effectively used as a functional filler.

• 한국기계가공학회지
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• 제20권11호
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• pp.86-91
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• 2021

Recently, functional clothes that can reduce deposition and/or penetration of fine dust have been developed. However, there are no methods to quantitatively evaluate the performance of these clothes. In this study, we developed a method to contaminate a fabric using fine dust and established an approach to quantitatively assess the degree of particle contamination on the fabric surface. Silicate powder was chosen as the particle to simulate fine dust because silicate particles are fluorescent under UV light; therefore, they can be distinguished from any color of non-fluorescent fabric surface. A camera with a high-resolution lens system was used to scan the surface of the contaminated fabric surface, and the degree of particle contamination of the fabric surface was analyzed in terms of the pixels corresponding to the area of the fabric surface contaminated by silicate particles. Finished or unfinished nylon fabrics as well as cotton fabrics were contaminated with silicate particles, and their surfaces were scanned using the established camera. The proposed assessment method was found to be useful for quantitatively comparing the degree of particle contamination of the fabrics.