• E2M - 전기 전자와 첨단 소재
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• 제8권4호
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• pp.400-405
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• 1995

ZnO films have been grown easily with the conventional thermal evaporation method on SiO$\_$2/ coated Si wafers. Anhydrous zinc acetate has been used as evaporation source. Zinc-acetate was directly heated in the laboratory-made brass boat. Zinc-acetate was sublimed at the boat temperature of about 220.deg. C. The substrates were heated to 600.deg. C with home made tantalium heater. Oxygen has been flowed into the deposition chamber to change the partial pressure of oxygen. X-ray diffraction patterns showed all the films to be amorphous. The films deposited at high oxygen pressure exhibit higher resistivity than films at low pressure. Energy dispersive spectroscopy(EDS) and rutherford backscattering spectrometry(RBS) were conducted on the films to reveal the composition of the ZnO films.

• 진공이야기
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• 제2권3호
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• pp.11-15
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• 2015

Particle characteristics diagnosis system (PCDS) was developed to measure submicron particle characteristics by modulation of particle beam mass spectrometry (PBMS) with scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). It is possible to measure the particle size distribution in real-time, and the shape, composition can be measured in sequence keeping vacuum condition. Apparatus was calibrated by measuring the size classified NaCl particle which generated at atmospheric pressure. After the calibration, particles were sampled from the exhaust line of plasma enhanced chemical vapor deposition (PECVD) process and measured. Result confirms that PCDS is capable for analyzing particles in vacuum condition.

• 전기화학회지
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• 제21권1호
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• pp.12-20
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• 2018

To solve low cycle efficiency of the zinc anode in Zn-air batteries by corrosion, this study examined the effects of Al as a cathodic protection additive to Zn. The Al-mixed Zn anodes were produced by mixing Zn and Al powder (1, 2, and 3 wt. %). To compare the effects of the Al additive, Si was selected under the same conditions. The morphology and elemental composition of the additives in the Zn were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, and inductively coupled plasma - mass spectrometry. The anti-corrosion effects of the Al and Si-mixed Zn anodes were examined by linear polarization. Cyclic voltammetry and charge-discharge tests were conducted to evaluate the electrochemical performance of the Al and Si-mixed Zn anodes. As a result, the Al-mixed Zn anodes showed highest corrosion resistance and cycling performance. Among these, the 2 wt.% Al-mixed Zn anodes exhibited best electrochemical performance.

• Korean Journal of Chemical Engineering
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• 제35권12호
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• pp.2379-2383
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• 2018

We report a facile one-pot aqueous-phase synthesis of PdAu bimetallic nanoparticles with different Pd/Au ratio. The synthesis was conducted by co-reduction of Pd and Au precursor using ascorbic acid as a reducing agent and in the presence of polyallylamine hydrochloride (PAH). By high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and energy-dispersive X-ray spectrometry (EDS) analyses, we found that the synthesized nanoparticles had an onion-like core/shell/shell/shell structure with Au-rich core, Pd-rich shell, Au-rich shell, and Pd shell, respectively. We also investigated the catalytic performance of the synthesized PdAu nanoparticles toward hydrogen peroxide generation reaction.

• Elastomers and Composites
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• 제56권3호
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• pp.113-116
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• 2021

In this study, we report a facile fabrication of multi-walled carbon nanotubes (MWCNTs)-CuO composites synthesized by a microwave method using MWCNTs and copper oxide (CuO). The number of copper hydrate precursors affect the size and number of CuO domains formed along the MWCNTs in the composites. The domain size is controllable from 239 nm to 348 nm. The composites are characterized by transmission electron microscopy, energy dispersive spectrometry, X-ray diffraction (XRD), Raman spectroscopy, and UV-Vis spectroscopy. The CuO produced in the composites is confirmed to be tenorite with a monoclinic crystal structure through the XRD patterns of (-111), (111) and (-202).

• Journal of the Korean Wood Science and Technology
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• 제51권2호
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• pp.69-80
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• 2023

This study conducted scientific analyses on eight objects of wooden lacquerware to understand the manufacturing techniques of wooden lacquerware in the late Joseon Dynasty. The results of lacquer layer analysis with a microscope and scanning electron microscopy-energy dispersive X-ray spectrometry revealed that most samples were composed of 1-3 lacquer layers. Moreover, a red-colored layer was found to be red ocher and cinnabar, and Fourier-transform infrared spectroscopy analysis was carried out to determine the components of the lacquer layer. The detected components were mostly lacquer and partially cashew shell nut liquid.

• Nuclear Engineering and Technology
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• 제55권8호
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• pp.2742-2746
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• 2023

The corrosion behavior of copper immersed in dilute oxychloride solution (100 mM) was studied through surface investigation and in-situ monitoring of open-circuit potential. The copper corrosion was initiated with copper dissolution into a form of CuCl^-₂, resulting in mass decrease within the first 40 h of immersion. This was followed by a hydrolysis reaction initiated by the CuCl^-₂ at the copper surface, after which oxide products were formed and deposited on the surface, resulting in a mass increase. The formation of nucleation sites for copper oxide and its lateral extension during the corrosion process were examined using focused ion beam (FIB)-scanning electron microscopy (SEM). The presence of metastable compounds such as atacamite (CuCl₂·3Cu(OH)₂) on the corroded copper surface was revealed by X-ray photoelectron spectra (XPS) and transmission electron microscopy (TEM)-energy dispersive spectrometry (EDS) analysis.

• Journal of Radiation Protection and Research
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• 제42권1호
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• pp.33-41
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• 2017

Background: Phosphate rock and its by-product are widely used in various industries to produce phosphoric acid, gypsum, gypsum board, and fertilizer. Owing to its high level of natural radioactive nuclides (e.g., $^{238}U$ and $^{226}Ra$), the radiological safety of workers who work with phosphate rock should be systematically managed. In this study, $^{238}U$, $^{232}Th$, $^{226}Ra$, and $^{40}K$ levels were measured to analyze the transport characteristics of these radionuclides in the production cycle of phosphate rock. Materials and Methods: Energy dispersive X-ray fluorescence and gamma spectrometry were used to determine the activity of $^{238}U$, $^{232}Th$, $^{226}Ra$, and $^{40}K$. To evaluate the extent of secular disequilibrium, the analytical results were compared using statistical methods. Finally, the distribution of radioactivity across different stages of the phosphate rock production cycle was evaluated. Results and Discussion: The concentration ratios of $^{226}Ra$ and $^{238}U$ in phosphate rock were close to 1.0, while those found in gypsum and fertilizer were extremely different, reflecting disequilibrium after the chemical reaction process. The nuclide with the highest activity level in the production cycle of phosphate rock was $^{40}K$, and the median $^{40}K$ activity was $8.972Bq{\cdot}g^{-1}$ and $1.496Bq{\cdot}g^{-1}$, respectively. For the $^{238}U$ series, the activity of $^{238}U$ and $^{226}Ra$ was greatest in phosphate rock, and the distribution of activity values clearly showed the transport characteristics of the radionuclides, both for the byproducts of the decay sequences and for their final products. Conclusion: Although the activity of $^{40}K$ in k-related fertilizer was relatively high, it made a relatively low contribution to the total radiological effect. However, the activity levels of $^{226}Ra$ and $^{238}U$ in phosphate rock were found to be relatively high, near the upper end of the acceptable limits. Therefore, it is necessary to systematically manage the radiological safety of workers engaged in phosphate rock processing.

• Applied Microscopy
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• 제39권1호
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• pp.41-48
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• 2009

본 연구는 색조화장품에 사용되는 진주광택안료의 특성을 주사전자현미경과 에너지분산분광분석기 및 열분석기를 사용하여 규명하였다. 본 연구에 사용된 인공합성 진주광택안료를 여성의 볼과 눈두덩 부위에 화장을 한 후 육안으로 관찰하였을 때 진주 광택안료는 보는 각도에 따라 흰색에서 보라색까지 다양한 색조로 빛을 반사하였다. 진주광택안료의 주사전자현미경 관찰 결과 안료는 얇은 판상의 다각형의 형태를 하고 있었으며 크기는 규격화된 모양이 아니고 다양하게 관찰되었다. 이런 조각의 크기는 약 $30{\mu}m$에서 $300{\mu}m$까지 측정되었고 안료 조각은 끝이 뾰족하거나 각진 상태로 존재하였다. 고배율의 주사전자현미경상에서 안료조각의 모서리 부위와 측면은 날카롭지 않은 타원형의 형태로 나타났으며 두께는 약 $9{\mu}m$로 측정되었다. 안료조각 표면은 직경이 약 60 nm의 이산화티탄 입자들에 의해서 피복되어 있었다. 진주광택안료의 에너지분산분석기를 사용하여 구성 원소 성분을 분석한 결과 안료의 표면은 O, Si, C, Na, Ca, Ti, Zn 등이 검출되었고 안료의 측면 부위도 동일한 성분들이 검출되었다. 이들 안료는 운모 티타니아(mica titania)로 확인되었다. 진주광택안료의 열분석 결과 초기 $100^{\circ}C$부터 $800^{\circ}C$까지 중량 감소는 큰 차이를 보이지 않았다. 열분석 결과 $115^{\circ}C$에서 1.1% 중량 감소를 하였고 $416^{\circ}C$에서 1.7% 감소하였으며 $797^{\circ}C$ 에서 1.9%의 중량이 감소된 것을 확인하였다.

• Journal of Korean Vacuum Science & Technology
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• 제6권2호
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• pp.92-96
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• 2002

In this paper, we treated the Ni$_3$Al based alloy samples with intense pulsed ion beams (IPIB) at the beam parameters of 250KV acceleration voltage, 100 - 200 A/cm$^2$ current density and 60 u pulse duration. We simulated the thermal-mechanical process near the surface of Ni$_3$Al based alloy with our STEIPIB codes. The surface morphology and the cross-section microstructures of samples were observed with SEM, the composition of the sample surface layer was determined by X-ray Energy Dispersive Spectrometry (XEDS) and the microstructure on the surface was observed by Transmission Electron Microscope (TEM). The results show that heating rate increases with the current density of IPIB and cooling rate reached highest value less than 150 A/cm$^2$. The irradiation of IPIB induced the segregation of Mo and adequate beam parameter can improve anti-oxidation properly of IC6 alloy. Some craters come from extraneous debris and liquid droplets, and some maybe due to the melting of the intersection region of interphase. Increasing the pulse number enlarges average size of craters and decreases number density of craters.