• Journal of Welding and Joining
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• 제35권3호
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• pp.52-61
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• 2017

Transient liquid phase (TLP) bonding is essential technology to repair micro-cracking on the airfoil of blades and vanes for gas turbines. Understanding of the characteristics of TLP bonding of the superalloys is necessary in the application of the technology for repairing these components. In this study, the focus was on investigating TLP bonding characteristics of ${\gamma}^{\prime}$ precipitation strengthened Ni based superalloy. TLP bonding was carried out with an amorphous filler metal in various bonding conditions, and the microstructural characterization was investigated through optical microscopy (OM) and electron probe micro-analysis (EPMA). The experimantal results explained clearly that bonding temperatures had critical effects on the TLP bonding behaviors, and that isothermal solidication of the joints made at higher temperatures than $1170^{\circ}C$ was controlled by Ti diffusion instead of B.

• 대한치과보철학회지
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• 제24권1호
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• pp.27-31
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• 1986

The purpose of this study was to discover the elemental change of the tracemetal surface of the precious porcelain alloy. The alloy was degudent H. For this purpose, the following experiment was made the analysis of the elemental change of the surface precious gold porcelain alloy were done by EDXA, and EPMA. The result is as follows, The Indium was transported to the alloy surface and its segregation to within a few microns of the porcelain-metal interface.

• Journal of Radiation Protection and Research
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• 제34권2호
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• pp.65-68
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• 2009

Metal-semiconductor contact is very important for the operating property of semiconductor detector. $Cd_{0.96}$ $Zn_{0.04}$ Te semiconductor crystal was grown with Bridgman method, and the crystal was cut and polished. EPMA (Electron Probe Micro Analyzer) and ICP-MS (Inductively Coupled Plasma Mass Spectrometry) analysis were done to obtain the chemical composition and impurity of the crystal. Metal contact was deposited with thermal evaporator on both sides of the crystal. Detectors with Au/CZT/Au and In/CZT/Au structure were made, and I-V curve and the energy spectrum were measured with the detectors. It could be seen that the detector with the In/CZT/Au structure has superior property than the detector with Au/CZT/Au structure when the crystal resistivity was low. However, the metal contact structure effect becomes low when the crystal resistivity was high.

• 한국결정성장학회지
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• 제3권1호
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• pp.85-92
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• 1993

커다란 olivine 단결정을 image furnace(floating zone furnace)를 사용하여 산소분압의 조절하에서 성장시켰다. 결정은 투명하였으며 길이가 65mm, 직경이 8mm였다. 산소분압이 감소할 때 결정내 제2상이 증가하여 결정을 엷은 갈색에서 짙은 갈색으로 변화시켰다. 이 제2상은 EPMA결과 Mg가 기저를 이룬 것에 Si와 Fe가 solid solution을 형성한 것이었다.

• 한국물환경학회지
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• 제23권2호
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• pp.184-187
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• 2007

The compositional and morphological analyses have been carried out by employing XRD, EPMA, and SEM for the black-colored precipitate which is formed on the surface of heating appliances by heating tap water. XRD analysis has showed that the precipitate was mainly composed of calcium carbonate with a crystal structure of calcite. Also, small amounts of precipitate by SEM showed that the microscopic shape of the precipitate was usually angular spherical.

• 한국재료학회지
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• 제17권10호
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• pp.548-554
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• 2007

[ $BaTiO_3$ ] thick film by an interfacial polymerization method was prepared at the liquid/liquid interface between benzyl alcohol saturated solution with the basic catalyst [diethyl amine ($NHEt_2$) or triethylamine ($NEt_3$)], and the water dissolved with $TiO_2$ and $Ba(CH_3COO)_2$. The film thickness increased gradually with an increase in diethyl amine($NHEt_2$) or triethylamine($NEt_3$) volume and the reaction time. The homogeneity of $BaTiO_3$ thick film after sintered at $600^{\circ}C$ was confirmed by EPMA analysis, which showed that both of Ba and Ti element were homogeneously distributed on the surface as well as in the perpendicular direction of the film. The thickness of $BaTiO_3$ film obtained by this process was $8.75\;{\mu}m$.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 춘계학술논문요약집
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• pp.51-52
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• 2018

Selective oxidation of RE elements from the U/RE metal ingot was studied in this paper using electrochemical process. Constant potential of -1.7V was applied between anode and cathode, where the potential value corresponds to standard potentials between actinide and rare earth materials. When the current values approached to nearly 0 mA, the reaction was finished. It is confirmed from the EPMA analysis that only U part of the U/RE ingot was remained. The metal recovered to the zinc cathode was obtained through the distillation process and it is being chemically analyzed in the KAERI analytical laboratory.

• Asian Journal of Atmospheric Environment
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• 제4권2호
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• pp.97-105
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• 2010

A quantitative single particle analytical technique, denoted low-Z particle electron probe X-ray microanalysis (low-Z particle EPMA), was applied to characterize particulate matters collected at two underground subway stations, Jegidong and Yangje stations, in Seoul, Korea. To clearly identify the source of the indoor aerosols in the subway stations, four sets of samples were collected at four different locations within the subway stations: in the tunnel; at the platform; near the ticket office; nearby outdoors. Aerosol samples collected on stages 2 and 3 ($D_p$: $10-2.5\;{\mu}m$ and $2.5-1.0\;{\mu}m$, respectively) in a 3-stage Dekati $PM_{10}$ impactor were investigated. Samples were collected during summertime in 2009. The major chemical species observed in the subway particle samples were Fe-containing, carbonaceous, and soil-derived particles, and secondary aerosols such as nitrates and sulfates. Among them, Fe-containing particles were the most popular. The tunnel samples contained 85-88% of Fe-containing particles, with the abundance of Fe-containing particles decreasing as the distances of sampling locations from the tunnel increased. The Fe-containing subway particles were generated mainly from mechanical wear and friction processes at rail-wheel-brake interfaces. Carbonaceous, soil-derived, and secondary nitrate and/or sulfate particles observed in the underground subway particles likely flowed in from the outdoor environment by human activities and the air-exchange between the subway system and the outdoors. In addition, since the platform screen doors (PSDs) limit air-mixing between the tunnel and the platform, samples collected at the platform at the Yangjae station (with PSDs) showed a marked decrease in the relative abundances of Fe-containing particles compared to the Jegidong station (without PSDs).

• 한국광물학회지
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• 제17권1호
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• pp.99-114
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• 2004

방사성폐기물의 처분연구와 관련하여 대전 유성지역 화강암내 심부시추공 시추코아의 단열 광물들에 대한 광물학적 특성을 연구하였다. 유성지역의 심부시추공들에는 다수의 단열대가 발달해 있으며 국지적인 열수변질작용이 중첩되어 있다. YS-01 시추코아에 대한 전암분석결과 -90 m∼-130 m 구간과 -230 m ∼-250 m 구간에서 급격한 $SiO_2$ 함량 감소와 $_Al2$$O_3$, CaO, L.O.I 값의 증가가 관찰되며 이는 단열충전광물의 생성과 관련이 있다. 이러한 단열충전광물에 대한 XRD분석결과 불석광물(로몬타이트, 휼란다이트), 방해석, 일라이트($2M_1$과 $1M_{d}$ 다형), 녹니석, 녹염석, 카올리나이트 등이 확인되었으며, 산출되는 양은 방해석 불석광물 > 일라이트 > 녹염석 녹니석 > 카올리나이트의 순이다. SEM관찰 및 EPMA 분석결과, 단열충전광물들의 심도에 따른 조직 및 화학특성의 변화는 관찰되지 않는다. 연구지역은 화강암반내에 발달된 단열대가 지하수의 유동로로 작용하여 오랜 기간에 걸친 물-암석 반응이 진행되었고, 또한 저온의 열수변질작용이 중첩되었기 때문에 이들에 의한 단열충전광물의 생성기원 연구가 필요하다.

• 한국광물학회지
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• 제21권1호
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• pp.85-98
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• 2008

경북 봉화군 소천면의 선캠브리아기 변성퇴적암 내에는 석회규산염층이 산출되며, 이 석회규산염층은 두께 $14{\sim}18\;m$ 정도로 층리면에 평행하게 협재되어 있다. 이 암층에는 방해석, 백운석, 사문석, 투각섬석이 주로 포함되고, 일부에서 활석이 소량 포함된다. 사문석은 석회규산염층의 중상부에 다량 함유되고 투각섬석은 하부층에서 주로 산출한다. 사문석이 많이 포함된 암석일수록 짙은 녹색을 나타낸다. XRD 및 FT-IR의 분석결과, 이곳의 사문석광물은 안티고라이트에 해당하는 것으로 나타났으며, SEM의 관찰에서도 안티고라이트의 판상 형태가 잘 나타났다. EPMA에 의한 이 사문석의 성분 분석의 결과, 안티고라이트의 이상적인 조성($SiO_2$: 44.3 wt% and MgO: 40.8 wt%)에 가깝게 나타났으며, 이를 통하여 계산된 구조식은 $Mg_{2.82}Al_{0.04}Fe^{3+}_{0.04}Si_{2.05}O_5(OH)_4$으로 나타났다. 석회규산염층은 구성 광물 및 산상 등을 검토해 본 결과, 퇴적 당시 환경에 따른 퇴적물의 광물 및 화학성분의 차이를 가지는 석회질 퇴적암이 변성작용을 받아 형성된 것으로 보인다. 안티고라이트가 다량 함유되는 상부층은 투각섬석이 포함되는 하부층에 비해 상대적으로 Mg이 더 풍부한 퇴적암으로 구성되었을 것으로 사료된다.