• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2008년도 춘계학술대회 논문집
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• pp.137-138
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• 2008

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.398-403
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• 2001

There is a potential usability of electric arc furnace(EAF) dust produced during the iron manufacturing process as a recycled resource, because valuable materials such as Zn, Pb and Fe are contained in it. In this study, metallic Zn was recycled from the fine electric arc furnace dust by a solid state reduction method using carbon at relatively low temperature. It was possible to recover metallic zinc by using of high vapour pressure of zinc with this reduction method. The feasibility of recycled zinc for cold bonded pellet(CBP) was investigated. The main composition of EAF dust were franklinite(ZnFe$_2$O$_4$), magnetite(Fe$_3$O$_4$) and zincite(ZnO), and Pb and Cl were completely removed by a heat treatment in oxidation environment. The reduction ratio increased as the solid carbon content increased, and it increased with decreasing of dust particle size and increasing of compaction pressure due to a increase of contact area.

• 한국대기환경학회지
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• 제11권2호
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• pp.191-198
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• 1995

In order to evaluate the distribution and behaviour of atmospheric particulate metals in high-altitude area, we collected 22 aerosol samples using a high volume air sampler at Soback Mt. Meteorological Observation Station from Jan. to Nov. 1993 and analysed for metals (Al, Fe, Mg, Na, Ca, Mn, Co, Ni, Cu, Zn, Cd, and Pb) with ICP/AES and ICP/MS. Although sampling site is located in high-altitude and far from local sources of atmospheric pollutants, enrichments of metals are 2 times higher than those of western coastal reural area. This fact may imply that of metallic pollutants in the coastal rural site were came from further western side (e.g. China), atmospheric metals in this study area contain the signal of metropolitan cities located in the main wind direction (NNW). Sea salts are negligible in the aerosol particle population because reference elements of sea salts (Na, Mg) are all originated from soil particles. The contents of soil particles in aerosols are highest in spring and lowest in winter. Atmospheric enriched elements (Ni, Cu, Zn, Cd and Pb) are diluted with soil particles, especially during the yellow sand period. The results of factor analysis suggest possibility of interpreting their chemical significance in terms of sources (soil, pollutants) and gas-particle conversion processes (formation of ammonium sulfates, ammonium nitrates and/or their mixtures).

• 한국항공우주학회지
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• 제44권7호
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• pp.593-602
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• 2016

본 연구에서는 근접연계방식의 초음속기체 금속분말 미립화장치에 대한 수치해석을 수행하였다. 액체금속의 미립화 과정에서 발생하는 1, 2차 액적분열을 모사하기 위해서 난류 모델을 선정하고 VOF(Volume of Fluid), DPM(Discrete Phase Model) 해석을 차례대로 수행하였다. 해석결과, Level-Set function 분포도를 통해 1차 분열액적의 직경을 계산할 수 있었으며 이 데이터를 DPM 해석에 반영해 도메인 출구에서 수집된 입자들의 최종직경분포를 확인할 수 있었다.

• 한국분말재료학회지
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• 제23권6호
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• pp.409-413
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• 2016

Electrical wire explosion in liquid media is a promising method for producing metallic nanopowders. It is possible to obtain high-purity metallic nanoparticles and uniform-sized nanopowder with excellent dispersion stability using this electrical wire explosion method. In this study, Ni-Fe alloy nanopowders with core-shell structures are fabricated via the electrical explosion of Ni-Fe alloy wires 0.1 mm in diameter and 20 mm in length in de-ionized water. The size and shape of the powders are investigated by field-emission scanning electron microscopy, transmission electron microscopy, and laser particle size analysis. Phase analysis and grain size determination are conducted by X-ray diffraction. The result indicate that a core-shell structured Ni-Fe nanopowder is synthesized with an average particle size of approximately 28 nm, and nanosized Ni core particles are encapsulated by an Fe nanolayer.

• Elastomers and Composites
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• 제49권2호
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• pp.160-166
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• 2014

자동차 선도장용으로 알루미늄 페이스트를 사용하여 6가지 베이스코트용 포뮬레이션이 설계되었다. 알루미늄 페이스트는 pancake 형태의 금속 안료인 #501, #801, #601와 cornflake 형태의 금속 안료인 #750, #770, #790가 사용되었다. 베이스코트의 상대적인 경화 밀도는 #501, #801, #601, #750, #770, #790 순으로 증가하였다. T-bending, 내충격성, 테이핑 부착력은 경화 밀도의 증가에 따라 향상되었다. Cornflake 형태의 안료에 대한 외관(combined factor) 테스트에서 입자가 가장 작은 #790이 다른 두 가지(#750, #770)와 비교하였을 때 가장 좋은 combined factor를 보여 주었다.

• 대한기계학회논문집B
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• 제25권12호
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• pp.1802-1812
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• 2001

The purpose of this study is to analyze numerically the movement of particles included in turbulent fluid flow characteristics of metallic surfaces. To describe fluid flew, the incompressible Navier-Stokes equation discretized by the finite volume method were solved on the non-orthogonal coordinates with non-staggered variable arrangement, and the k-$\xi$ turbulence model was adapted. After fluid flow was calculated, particle movement was predicted from the Lagrangian approaches. Non-essential complexities were avoided by assuming that the particles had spherical shapes and the Stoke's drag formula only consisted of external farces acting upon them. In order to validate the numerical calculations, the results were compared with the experimental data reported in literature and agreed well with them. The drag force coefficient equation showed better agreement with the experimental data in the prediction of particle movement than the correction factor equation. Impact velocity and impact angle increased as inlet turbulence intensity decreased, relative jet height was lower. or the Reynolds number was larger.

• 한국수소및신에너지학회논문집
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• 제16권1호
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• pp.58-65
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• 2005

The $LaCrO_3$-dispersed Cr alloys for metallic interconnect of solid oxide fuel cell were prepared as a function of $LaCrO_3$ content in the range of 5 to 25 vol.% and were sintered at 1500$^{\circ}C$ under an Ar atmosphere with 5 vol.% $H_2$. The sintering and oxidation behaviors of these alloys were examined. The alloys indicated a good sinterability above 95% relative density at a given sintering condition, and their sintering densities is independent on $LaCrO_3$ content. The $LaCrO_3$ particles of the sintered alloys were concentrated on interfaces of Cr particles, and the size of the Cr particles increased with decreasing $LaCrO_3$ content, which is caused by inhibited grain growth of Cr particle by $LaCrO_3$ particle. The oxidation test showed all $LaCrO_3$-dispersed Cr alloys have good oxidation resistance as compared with pure Cr, which is attributed to presence of $LaCrO_3$ at the interface at which the oxidation reaction occurs rapidly. The Cr alloys with about 15 vol.% $LaCrO_3$ are very resistant to oxidation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1303-1305
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• 1998

In order to reduce or avoid oxidation problem at operation the interconnects in SOFCs have so far mostly been made of ceramic material. It has high chemical stability both under cathode and anode condition, relatively thermal expansion coefficient that matchs that of electrolyte material YSZ. But this material shown rather weak in the low oxygen atmosphere and thermal shock, and it has lower mechanical strength than alloys. To avoid these problems one may consider to use metals or alloys as materials for interconnects. Metallic interconnects are advantageous because of their high thermal and electronic conductivities. But it has some problems, Those are high thermal expansion and oxidation at high temperature in air. To solve these problems in the interconnection material in this study, $LaCrO_3$-dispersed Cr alloys for metallic interconnector of SOFC have been investigated as a fuction of $LaCrO_3$ content in the range of 5 to 25 vol.%. The Cr alloy were prepared by mixing Cr and $LaCrO_3$ powders in high-energy ball mill for 48h and by sintering under Ar atmosphere with 5vol.% $H_2$ for 10h at $1500^{\circ}C$. The alloys had a relative density of 95% and above. The Cr alloys in composed of two kind of small $LaCrO_3$ and large Cr particles. As the $LaCrO_3$ content increased, the Cr particle size decreased but the $LaCrO_3$ particle size remained contant. Also the oxidation tests show that the $LaCrO_3$-dispersed Cr is very resistant to oxidation in air. These results means that $LaCrO_3$-dispersed Cr is a useful material for metallic interconnect of planar SOFC.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.417-418
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• 2002

The dry sliding tribological characteristics were investigated using SiC particle-reinforced aluminum composites against semi-metallic frictional materials. The experimental results have indicated that, whether under the condition of continuous braking or not, the wear rates of SiC particle reinforced composites are much less than that of gray cast iron which is used as one of the common brake disk materials. At the same time, their frictional coefficients are about the same.