• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.478-480
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• 2001

Fe-base amorphous films exhibit large saturation magnetostriction and soft magnetic Properties, which make them suitable for strain sensor applications. Most important material properties for the performance of these elements are the superior soft magnetic properties, such as high permeability and small coercive force, as well as magnetoelastic properties. It is well known that the strain generated in film deposition and/or post-heat treatment processes is one of important material properties, which effects on the soft magnetic properties of the film via magnetoelastic coupling. In this study, the effect of an isotropic strain in plane of magnetic films have been performed experimently. Amorphous films with the composition of (F $e_{90}$ $Co_{10}$)$_{78}$S $i_{l2}$ $B_{10}$ were employed in this study. The film with 5${\mu}{\textrm}{m}$ thick was deposed onto the polyimide substrate with 50${\mu}{\textrm}{m}$ thick by virtue of RF sputtering. The film was subject to post annealing with a static magnetic field with 500Oe magnetic field intensity at 35$0^{\circ}C$ for 1 hour. The polyimide substrate with the film was bonded with an adhesive on PZT piezoelectric substrate with 600${\mu}{\textrm}{m}$ thick in applying voltage of 500V. The change in MH loops of films due to the isotropic strain was measured by using VSM. The coercive force was evaluated from MH loops. It has shown in the results that M-H loops of films are subject to change considerably with a dc voltage, resulting of the magnetization rotation from normal to plane direction as the applied voltage is changed from 500V to 250V.50V.V.

• 자원리싸이클링
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• 제2권4호
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• pp.33-41
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• 1993

본 연구에서는 전로슬래그 중에서 슬래그 부산에 의한 Cu의 회수 및 자산, 체질에 의한 Cu의 조기회수방법을 조사하였으며, 부산공정 시 부산용수로서 폐수사용의 가능성을 검사하였다. 또한 부산 등의 산별과정에 의해 얻어진 산물의 화학분석을 통하여 각 성분별 신화력을 조사하였다. 건식자산의 경우 300 Gauss에서 2시간 영각고화 슬래그에 있어서는 Cu 품위 60.7%, 회수율 39.2%의 정광을 얻고, 10시간 영각 고화 슬래그에 있어서는 Cu품위 54.0%, 회수율 17.9%의 정광을 얻었다. 습식자산의 경우 600 Gauss에서 10시간 영각 고화 슬래그의 경우 Cu품위 64.1%, 회수율 1.8%의 정광을 얻었다. 마광을 행한 영각 고화 10시간 시과에 대해, 사상산물에 대새서는 자산을 행하였고, 사하산물에 대해서는 부산을 행하였다. 이 결과 Cu품위 45.2%의 정광을 얻을 수 있었으며 이때 회수율은 93.5%를 나타냈다. 부산정광에서 Cu품위가 높을수록 As 품위는 상승하였으냐, Zn 및 Fe 품위는 감소하였으며, Pb 품위는 무관하였다. 이 결과 Cu품위 37.74%의 정광을 얻을 수 있었으며 이때 회수율은 94.79%를 나타내었다.

• Nuclear Engineering and Technology
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• 제52권6호
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• pp.1277-1281
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• 2020

A novel ceramic Gas Electron Multiplier (GEM) has been developed to meet the demand of high counting rate for the neutron detection which is an alternative to ³He-based detector at China Spallation Neutron Source (CSNS). An experiment was performed to measure the neutron transmittance of ceramic-GEM and FR4-GEM at the small angle neutron scattering (SANS) instrument. The result showed the ceramic-GEM has higher transmittance and less self-scattering especially for cold neutrons. One single ceramic GEM could give a gain of 10²-10⁴ in the mixture gas of Ar and CO₂ (90%:10%) and its energy resolution was about 27.7% by using ⁵⁵Fe X ray of 5.9 keV. A prototype has been developed in order to investigate the performances of the ceramic GEM-based neutron detector. Several neutron beam tests, including detection efficiency, spatial resolution, two-dimensional imaging, and wavelength spectrum, were carried out at CSNS and China Mianyang Research Reactor (CMRR). The results show that the ceramic GEM-based neutron detector is a good candidate to measure the high intensity neutrons.

• 한국전기전자재료학회논문지
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• 제30권7호
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• pp.427-431
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• 2017

In this paper, we discuss ${\beta}-Ga_2O_3$ thin films that have been grown on freestanding GaN (FS-GaN) using furnace oxidation. A GaN template was grown by horizontalhydride vapor phase epitaxy (HVPE), and FS-GaN was fabricated using the laser lift off (LLO) system. To obtain ${\beta}-Ga_2O_3$ thin film, FS-GaN was oxidized at $900{\sim}1,100^{\circ}C$. Surface and cross-section of prepared ${\beta}-Ga_2O_3$ thin films were observed by field emission scanning electron microscopy (FE-SEM). The single crystal FS-GaNs were changed to poly-crystal ${\beta}-Ga_2O_3$. The oxidized ${\beta}-Ga_2O_3$ thin film at $1,100^{\circ}C$ was peel off from FS-GaN. Next, oxidation of FS-GaNwas investigated for 0.5~12 hours with variation of the oxidation time. The thicknesses of ${\beta}-Ga_2O_3$ thin films were measured from 100 nm to 1,200 nm. Moreover, the 2-theta XRD result indicated that (-201), (-402), and (-603) peaks were confirmed. The intensity of peaks was increased with increased oxidation time. The ${\beta}-Ga_2O_3$ thin film was generated to oxidize FS-GaN.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.125-125
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• 2017

The roots of Platycodon grandiflorum are commonly used for treating bronchitis, asthma, tuberculosis, diabetes, and other inflammatory diseases. Since the molecular mechanism underlying the roots of the plant is unclear. Therefore, the present study was conducted to profile proteins from liquid cultured tetraploid roots of Platycodon grandi orum fl using high throughput proteome approach. Two-dimensional gels stained with CBB, a total of 659 differentially expressed proteins were identified from the liquid medium cultured tetraploid roots of which 32 proteins spots (${\geq}1.5-fold$) were sorted for mass spectrometry analysis. Out of these 32 proteins, a total of 15 proteins were up-regulated such as Serine carboxypeptidase-like 27, Transcription factor bHLH150, 60 kDa jasmonate-induced protein, Cytosolic Fe-S cluster assembly factor NBP35, Regulatory associated protein of TOR 2 and a total of 17 proteins were down-regulated such as Protein G1-like2, Phenylalanine ammonia-lyase, Fructokinase-2, Trihelix transcription factor GT-3a, Guanine nucleotide-binding protein alpha-1 subunit. However, the frequency distribution of identified proteins was carried out within functional categories based on molecular functions, cellular components, and biological processes. Functional categorization revealed that the most of the identified proteins from the explants were mainly associated with the nucleic acid binding, oxidoreductase, transferase activity, protein binding and hydrolase activity. In addition, the proteomic feedback of tetraploid roots of P. grandiflorum may potentially be used to understand the characteristics of proteins and their functions.

• 자원환경지질
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• 제29권5호
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• pp.597-613
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• 1996

The tonnage of copper and tungsten produced at Dalseong mine by Taehan Tungsten Mining Company from 1961 to 1971 was 48,704 tons (M/T) of 4 wt.% Cu and 1,620 tons (S/T) of 70wt.% WO, but the mine was closed in 1974. Kyeongsan mine is a small abandoned cobalt mine with no data of production. To investigate the pollution level of the mine areas, soils, plants (Ohwi and Pampanini), stream waters and stream sediments were taken and Fe, Mn, Cu, Pb, Zn, Ni, Co, Cd and Cr were analysed by ICP. Soils are considerably contaminated by the heavy metals related to ore deposits, The heavy metal contents in plants vary with the species and parts of plants. Stream waters are anomalously high in heavy metals in the vicinity of the mines but the contents decrease downstream in the process of dilution and precipiation. However, heavy metal contents increase very high in stream sediments due to precipiation. To protect environmental damages caused by acid mine drainages wetlands must be constructed outside pits, and it is necessary to fill pits with waters, limestone chips and organic materials, which give reducing and alkaline condition to ores. Under the condition pyrite is protected from oxidation and aqueous iron sulphates precipitate to form stable secondary pyrite.

• The Journal of Advanced Prosthodontics
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• 제6권4호
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• pp.302-308
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• 2014

PURPOSE. The purpose of this study was to compare removal torques and surface topography between laser treated and sandblasted, large-grit, acid-etched (SLA) treated implants. MATERIALS AND METHODS. Laser-treated implants (experimental group) and SLA-treated implants (control group) 8 mm in length and 3.4 mm in diameter were inserted into both sides of the tibiae of 12 rabbits. Surface analysis was accomplished using a field emission scanning electron microscope (FE-SEM; Hitachi S-4800; Japan) under ${\times}25$, ${\times}150$ and ${\times}1,000$ magnification. Surface components were analyzed using energy dispersive spectroscopy (EDS). Rabbits were sacrificed after a 6-week healing period. The removal torque was measured using the MGT-12 digital torque meter (Mark-10 Co., Copiague, NY, USA). RESULTS. In the experimental group, the surface analysis showed uniform porous structures under ${\times}25$, ${\times}150$ and ${\times}1,000$ magnification. Pore sizes in the experimental group were 20-40 mm and consisted of numerous small pores, whereas pore sizes in the control group were 0.5-2.0 mm. EDS analysis showed no significant difference between the two groups. The mean removal torque in the laser-treated and the SLA-treated implant groups were 79.4 Ncm (SD = 20.4; range 34.6-104.3 Ncm) and 52.7 Ncm (SD = 17.2; range 18.7-73.8 Ncm), respectively. The removal torque in the laser-treated surface implant group was significantly higher than that in the control group (P=.004). CONCLUSION. In this study, removal torque values were significantly higher for laser-treated surface implants than for SLA-treated surface implants.

• Asian Pacific Journal of Cancer Prevention
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• 제15권20호
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• pp.8981-8985
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• 2014

Objective: To explore the effect of lysine-coated oxide magnetic nanoparticles (Lys@MNPs) on viability and apoptosis of A549 lung cancer cells. Methods: Transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and Zeta potentiometric analyzer were employed to characterize Lys@MNPs. Then Lys@MNPs and lung cancer A549 cells were co-cultured to study the effect of Lys@MNPs on cell viability and apoptosis. The pathway of Lys@MNPs entering A549 cells was detected by TEM and cell imaging by 1.5 T MRI. Results: Lys@MNPs were 10.2 nm in grain diameter, characterized by small size, positive charge, and superparamagnetism. Under low-dose concentration of Lys@MNPs (< $40{\mu}g/mL$), the survival rate of A549 cells was decreased but remained higher than 95% while under high-dose concentration ($100{\mu}g/mL$), the survival ratewas still higher than 80%, which suggested Lys@MNPs had limited influence on the viability of A549 cells, with good biocompatibility and and no induction of apoptosis. Moreover, high affinity for cytomembranes, was demonstrated presenting good imaging effects. Conclusion: Lys@MNPs can be regarded as a good MRI negative contrast agents, with promising prospects in biomedicine.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.86.2-86.2
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• 2011

저온형 연료전지인 직접 메탄올 연료전지(Direct Methanol Fuel Cells, DMFC)는 친환경적인 발전 시스템, 높은 에너지 효율의 장점 때문에 주목을 받고 있으나 연료극의 촉매로 사용되는 금속은 고가의 귀금속인 Pt와 Ru가 요구되어 제조비용이 비싸기 때문에 촉매의 양을 줄이고, 반응 도중 생성되는 CO에 의한 촉매의 피독 문제 등 해결하여야 할 점이 산적해 있어 연료전지 중 촉매의 활성을 높이는 연구들이 활발히 이루어지고 있다. 종래의 MEA의 촉매층 제조공정은 우선 환원석출법에 의해 Pt-Ru/C를 합성하고 Nafion 용액에 혼합하여 Pt-Ru/C 슬러리를 제조한다. 이 방법에서는 carbon sheet에 spray 방법으로 Pt-Ru/C 촉매층이 만들어지기 때문에, Pt-Ru 촉매가 Nafion에 의해 부분적으로 매몰되어 촉매의 전기화학적 활성이 떨어지는 문제점이 있다. 이를 해결하는 방안으로 펄스전류를 이용하여 Pt-Ru 합금입자를 carbon sheet에 전기화학적으로 담지 시켜 Nafion에 매몰되는 것을 방지하는 펄스전해법 연구가 진행되고 있다. 그러나 촉매의 입자크기가 일반적으로 50~70 nm 이상으 크기 때문에 촉매의 낮은 활성이 문제점으로 야기되고 있다. 본 연구에서는 Pt-Ru/C 촉매층 제조 문제점을 해결하고, 촉매의 전기화학적 활성을 증가시키기 위해서 2~4 nm Pt-Ru 콜로이드를 전해액으로 사용하고, 전기영동법을 이용하여 Pt-Ru 나노 입자를 carbon sheet($1{\times}1cm^2$) 에 담지 시켰다. 전기영동법에서 균일한 Pt-Ru 촉매층의 제조를 위해 전류인가 방법으로는 펄스전류를 사용하였고, 실험변수로는 전해액 pH, duty cycle, 담지시간을 선정하였다. 합성된 Pt-Ru 콜로이드를 TEM분석으로 나노입자의 크기와 분산성 분석하였고, 콜로이드 나노입자의 표면전하 상태를 분석하기 위해 zeta-potential을 분석하였다. Pt-Ru/C의 촉매의 전기화학적 활성을 분석하기 위하여 0.5 M H_2SO_4$ 와 1 M $CH_3OH$ 혼합용액에 CV(Cyclic Voltammetry)실시하였고, carbon sheet 전극 상 Pt-Ru의 분산성 확인을 위하여 FE-SEM분석을 수행하였다.

• 한국해양학회지
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• 제13권2호
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• pp.11-16
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• 1978

최근에 와서 유류오염과 더불어 중금속에 의한 해양오염, 특히 연안오염은 공공 관심의 대상이 되고 있다. 어떤 해역의 오염정도는 그 해역의 해수 및 그 해역에 서식 하는 유기체(Organisms)와 더불어 그 해역 퇴적물의 오염물질함량으로부터 파악할 수 있다. 진해만과 부산해역은 공업단지와 대도시가 인접해 있고 또 선박의 출입이 잦기 때문에 중금속에 의해 오염될 가능성이 많다. 그러나 이 해역에 대한 중금속의 오염조사현황을 보면 수질에 대한 조사는 수차(Kwak et al., 1974, 국립수산진흥원, 1975, 1977)에 걸쳐 행하여 졌으나 퇴적물에 대해서는 진해만에 대한 2회의 조사(Lee et al., 1974, Hyun, 1974)가 있었을 뿐이다. 본 조사에서는 진해만과 부산해역 퇴적물의 중금속 오염실태를 알아보기 위해 이를 해역의 퇴적물을 채취하고 퇴적물중 구리, 납, 아연, 니켈, 코발트, 철, 망간등 7가지 중금속의 함량을 측정하였다.