• Journal of Electrochemical Science and Technology
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• 제14권3호
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• pp.231-242
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• 2023

Li₂O-based cathodes utilizing oxide-peroxide conversion are innovative next-generation cathodes that have the potential to surpass the capacity of current commercial cathodes. However, these cathodes are exposed to severe cathode-electrolyte side reactions owing to the formation of highly reactive superoxides (O^x-, 1 ≤ x < 2) from O^2- ions in the Li₂O structure during charging. Succinonitrile (SN) has been used as a stabilizer at the cathode/electrolyte interface to mitigate cathode-electrolyte side reactions. SN forms a protective layer through decomposition during cycling, potentially reducing unwanted side reactions at the interface. In this study, a composite of Li₂O and Ni-embedded reduced graphene oxide (LNGO) was used as the Li₂O-based cathode. The addition of SN effectively thinned the interfacial layer formed during cycling. The presence of a N-derived layer resulting from the decomposition of SN was observed after cycling, potentially suppressing the formation of undesirable reaction products and the growth of the interfacial layer. The cell with the SN additive exhibited an enhanced electrochemical performance, including increased usable capacity and improved cyclic performance. The results confirm that incorporating the SN additive effectively stabilizes the cathode-electrolyte interface in Li₂O-based cathodes.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.367-368
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• 2007

To investigate the 2nO thin films which are interested in the next generation of short wavelength LEDs and Lasers and UV photodetector with p-type inversion layer, the ZnO thin films were deposited by RF sputtering system. Gas ratios and work pressure is Ar : $O_2$ = 4 : 1 and 15 mTorr, respectively, and the purity of ZnO target is 5N. The ZnO thin films were deposited at 300, 450, and $650^{\circ}C$. The current-voltage, responsivity and quantum efficiency of devices were studied and compared with each devices.

• 한국환경과학회지
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• 제26권3호
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• pp.303-309
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• 2017

Aeration with low energy micro-bubble generation and $UV/H_2O_2$ processes was introduced to verify the possibility of oxidation treatment for acid mine drainage. During 10 hours of aeration with micro-bubbles, Fe and As concentrations were decreased to 18.1 and 61.8%, respectively, while Cu, Cd, Al were kept at influent concentrations. Other heavy metals such as Mn, Cr, Pb, Zn, and Ni concentrations fluctuated due to the repetition of oxidation and release. Twenty days of aeration indicated the oxidation possibility for Cu, Cd, and Al. With the employment of $UV/H_2O_2$ processes, more than 77% of Cu and Fe removed, whereas slightly more than 30% of Cd and Al removed.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.189.1-189.1
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• 2011

Global warming effect was intensified due to rapid growth of fossil fuel consumption caused by urbanization and industrialization. Various efforts was being done to solve the problems leading to anomaly climate such as flood, downpour, heavy snow. As a results of international efforts for management of global warming, Kyoto Protocol, which was passed in Kyoto, Japan in 1997, designated $CO_2$, $CH_4$, $N_2O$, HFCs, PFCs, $SF_6$ as a global warming gases. And IPCC(Intergovernmental Panel on Climate Change) suggested IPCC guideline for systematic establishment of national greenhouse gas inventory. Among five categories in IPCC guideline, the representative emission source of waste category is SWDS(solid waste disposal site). The concentrative research should progress for effective management of greenhouse gas related with waste. In this study, Tier1 and Tier2 methods which was suggested by 2006 IPCC(Intergovernmental Panel on Climate Change) guideline, was used to predict methane generation from C sanitary landfill located in Chungju area. To predict methane generation from C sanitary landfill, all factors were defaults values that were provided by 2006 IPCC guideline and Korea emission factors for Tier1 and Tier2 method. And economics of generated methane was estimated. From the predicted result using IPCC guideline, the methane generation was persistingly increased over a 9-year period(2000 ~ 2008). Aggregated amount of methane generation was about 3,017ton and 3,170ton predicted by Tier1 and Tier2, respectively. From the results of estimated economic value gained by generated methane from the C sanitary landfill for ten years from now(2010 ~ 2020), the profit was about 2.39 ~ 2.76 hundred million won.

• 한국광학회지
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• 제4권2호
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• pp.200-205
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• 1993

LiI$O_3$ 및 BBO 결정에서 Ti:sapphire 레이저에 대한 제2조화파 발생 실험을 실시하였다. LiI$O_3$ 는 5mm, 10mm의 두 종류를 이용하였으며 BBO의 길이는 7mm이었다. 780nm~810nm 영역에서의 LiI$O_3$ 및 BBO 결정에 대한 제2조화파 변환 효율을 측정하였고 이론과 비교하였다. 또, 펌프 출력에 따른 제2조화파의 출력을 측정함으로서 794nm에서의 제2조화파 변환 계수(conversion coefficient)를 구하였으며, 그 값은 LiI$O_3$ 결정에 대해 (1.06${\pm}0.05){\times}10^4W\;^1$(10mm), (5.28${\pm}0.33){\times}10^5\;W^1$(5mm), 이었고 7mm의 BBO에 대해서는(2.96${\pm}0.05){\times}10^5\;W^1$이었다.

• 한국재료학회지
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• 제23권10호
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• pp.580-585
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• 2013

To observe the formation of defects at the interface between an oxide semiconductor and $SiO_2$, ZnO was prepared on $SiO_2$ with various oxygen gas flow rates by RF magnetron sputtering deposition. The crystallinity of ZnO depends on the characteristic of the surface of the substrate. The crystallinity of ZnO on a Si wafer increased due to the activation of ionic interactions after an annealing process, whereas that of ZnO on $SiO_2$ changed due to the various types of defects which had formed as a result of the deposition conditions and the annealing process. To observe the chemical shift to understand of defect deformations at the interface between the ZnO and $SiO_2$, the O 1s electron spectra were convoluted into three sub-peaks by a Gaussian fitting. The O 1s electron spectra consisted of three peaks as metal oxygen (at 530.5 eV), $O^{2-}$ ions in an oxygen-deficient region (at 531.66 eV) and OH bonding (at 532.5 eV). In view of the crystallinity from the peak (103) in the XRD pattern, the metal oxygen increased with a decrease in the crystallinity. However, the low FWHM (full width at half maximum) at the (103) plane caused by the high crystallinity depended on the increment of the oxygen vacancies at 531.66 eV due to the generation of $O^{2-}$ ions in the oxygen-deficient region formed by thermal activation energy.

• 한국광학회지
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• 제31권3호
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• pp.142-147
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• 2020

본 연구에서는 Yb 광섬유 레이저 MOPA (master oscillator power amplifier) 시스템을 구축하여 고출력, 고효율의 근적외선 레이저 빔을 발진시키고, 이를 주기분극반전 준위상정합 비선형 광학 소자인 MgO:PPSLT에 단일 통과시키는 방식을 통하여 고출력 고효율 연속발진 녹색 레이저 빔을 생성하는 방법을 보고한다. 자발 펄싱을 억제할 수 있는 패브리-패롯 피드백 공진기 구조를 사용한 광섬유 레이저 주공진기를 사용하여 선폭이 좁고 선형 편광된 1064 nm 레이저 씨앗 빔을 안정적으로 생성할 수 있었으며, 이를 Yb 광섬유 증폭단에서 고출력으로 증폭시켰다. 증폭된 레이저 빔을 MgO:PPSLT에 통과시켜 고출력 고효율의 이차조화파를 얻을 수 있었는데, 이때 얻은 532 nm 레이저의 최고 출력은 기본 입사광의 출력이 25.0 W일 때 11.1 W였으며, 변환 효율은 44.4%를 얻었다.

• 한국수소및신에너지학회논문집
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• 제13권2호
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• pp.143-150
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• 2002

The thermal behavior of $(Co_{0.5}\;Mn_{0.5})Fe_2O_4$ prepared by a co-precipitation wasinvestigated for Hz generation by the thermochemical cycle. The reduction reaction of $(Co_{0.5}\;Mn_{0.5})Fe_2O_4$ started from $480^{\circ}C$, and the weight loss was 1.6 wt% up to $1100^{\circ}C$. At this reaction, $(Co_{0.5}\;Mn_{0.5})Fe_2O_4$ was reduced by release of oxygen bonded with the $Fe^{3+}$ ion in the B site of ($CO_{0.5}$ $(Co_{0.5}\;Mn_{0.5})Fe_2O_4$. In the $H_2O$ decomposition reaction, $H_2$ was generated by oxidationof reduced $(Co_{0.5}\;Mn_{0.5})Fe_2O_4$. The crystal structure of $(Co_{0.5}\;Mn_{0.5})Fe_2O_4$ for reduction reaction maintained spinel structure and the lattice constant of $(Co_{0.5}\;Mn_{0.5})Fe_2O_4$ ($8.41\AA$) was enlarged to $8.45\AA$. But the lattice constant of $(Co_{0.5}\;Mn_{0.5})Fe_2O_4$ after $H_2O$ decomposition reaction did not change to $8.45\AA$. Then, $(Co_{0.5}\;Mn_{0.5})Fe_2O_4$ is excellent material in the thermochemical cyclic reaction due to release oxygen at low temperature for the reduction reaction and produce $H_2$ maintaining crystal structure for redox reaction.

• Reproductive and Developmental Biology
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• 제29권3호
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• pp.155-162
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• 2005

본 연구는 돼지 정자 동결시 taurine과 $\alpha$-tocopherol의 첨가가 융해후 정자 성상과 정자 기능 활성산소계(reactive oxygen species; ROS)의 발생 정도 및 지질 산화(lipid peroxidation, LPO)에 미치는 영향을 구명하기 위하여 시행하였다. 1차 및 2차 희석액내 taurine과 $\alpha$-tocopherol이 첨가된 돼지 동결정액의 융해 후 정자 운동성 양상, 정자 생존성, 정자 기법을 적용하여 다음과 같은 결과를 얻었다. Taurine(25mM, 50mM), $\alpha$-tocopherol($500{\mu}M,\;1,000{\mu}M$ 단일처리군 그리고 taurine과 $\alpha$-tocopherol의 혼합처리군($25mM\~500{\mu}M\~1,000{\mu}M$)은 동결$\cdot$융해 후 대조군과 비해 정자 운동성과 생존성은 유의적인 차이를 나타내지 않았다. Taurine과 $\alpha$-tocopherol의 혼합처리군 $50mM\~1,000{\mu}M$에서 HOST, 점체 반응이 대조군과 비교하여 유의차는 인정되지 않았으나 다소 증가하였다. 동결$\cdot$융해 정자의 ROS 발생 억제를 위한 taurine과 $\alpha$-tocopherol의 모든 처리군은 대조군과 비교하여$\cdot\{O_2}{^-}$ 발생을 유의적으로 완화시키지 못하였다. 그러나 taurine 단일처리군(25mM), $\alpha$-tocopherol 단일처리군($50mM,\;1,000{\mu}M$)과 혼합처리군($25mM\~500mM,\;50mM\~1,000{\mu}M$은 $H_{2}O_{2}$의 발생을 대조군과 비교하여 유의적으로 완화시켰다(P<0.05). 동결$\cdot$융해 정자의 malondialdehyde의 생산은 taurine과 $\alpha$-tocopherol의 모든 처리군에서 대조군과 비교하여 유의적인 감소를 보였다(P<0.05). 이상의 결과를 종합해 보면 돼지 정액의 동결보존시 taurine와 $\alpha$-tocopherol 같은 항산화제의 처리는 ROS 발생과 LPO을 효과적으로 완화시킴에 따라 돼지 정액의 동결보존 효율을 증진시킬 수 있는 유용한 방법이라 사료된다.

• 한국컴퓨터정보학회지
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• 제2권1호
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• pp.121-129
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• 1995

결함 시뮬레이션은 테스트 생성의 중요한 과정이며 테스트가 올바른지 검증하거나 결함사전을 작성하는 데에 쓰인다. 본 논문에서는 회로의 신뢰성을 검증하기 위해 사용되는 테스트 패턴을 효율적으로 생성하기 위하여 역추적 결함 시뮬레이션 알고리즘을 제안하였다. 제안한 알고리즘의 기본구성은 초기화 과정, 역추적 결함 시뮬레이션 과정 및 입력패턴의 변화가 생겼을 때 즉 리스트변화가 있을때의 재계산 과정 등 3부분으로 되어 있다. 기본개념은 역추적 과정에서 출력선을 제어하지 못하는 입력을 커팅하므로서 최소의 결함리스트를 유지하는 것이며 리스트의 변화가 생겼을 때 논리변화가 일어나는 신호선만 재계산한다. 제안한 알고리즘은 기억장소의 요구도를 O(n)으로 줄이고 수행시간을 향상시켜 효율적임을 보인다.