• Bulletin of the Korean Chemical Society
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• 제6권4호
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• pp.214-217
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• 1985

Platinum(II) complexes of R-2,2'-diaminobinaphthyl (R-dabn), [Pt(R-dabn)(H2O)2]Cl2, [Pt(R-dabn)(R-Pn)]Cl2, [Pt(R-dabn)(R-bn)]Cl2, and platinum(II) complexes of S-2,2'-diaminobinaphthyl (S-dabn), [Pt(S-dabn)(H2O)2]Cl2, [Pt(S-dabn)(S-Pn)]Cl2, and [(Pt(S-dabn)(S-bn)]Cl2 have been prepared. (R-Pn and S-Pn are, respectively R- and S isomer of 2,3-diaminobutane). R-Pn and S-bn are, respectively R and S isomer of 2,3-diaminopropane). In the vicinity of the B-absorption band region of dabn, the circular dichroism spectra of platinum(Ⅱ) complexes of R-dabn series show a positive B-band followed by a negative higher energy A-band, which is generally understood as the splitting pattern for a ${\lambda}$ conformation, while the circular dichroism spectra of platinum(Ⅱ) complexes of S-dabn series show a negative B-band followed by a positive higher energy A-band in the long-axis polarized absorption region as expected for a $\delta$ conformation.

• 한국결정학회:학술대회논문집
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• 한국결정학회 2000년도 추계 학술연구발표회
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• pp.14-14
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• 2000

• 펄프종이기술
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• 제37권4호통권112호
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• pp.60-66
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• 2005

• 한국재료학회:학술대회논문집
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• 한국재료학회 1999년도 춘계학술발표강연 및 눈문개요집
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• pp.40-40
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• 1999

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.995-996
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• 2011

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.230.1-230.1
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• 2010

조촉매(Promotor)인 Na은 수성가스전이(Water Gas Shift, WGS) 반응 시 생성된 포름산염의 C-H결합을 쉽게 분해하는 역할을 한다. 본 연구에서는 $Pt/CeO_2$ 촉매의 성능 향상을 위해 Na의 담지량을 변화시켜 촉매적 활성을 비교하여 보았다. 제조된 담체는 침전법(Precipitation)을 사용하여 제조하였으며 $500^{\circ}C$에서 6시간 소성하였다. Pt 담지량은 1wt%로 고정하였고 Na 담지량은 1 wt%~5 wt%로 변화를 주어 동시(공)-함침법(Co-incipient wetness method)으로 담지 시켰다. 반응 실험은 공간속도(Gas Hourly Space Velocity, GHSV) $45,385h^{-1}$에서 수행하였다. WGS 반응 결과 3 wt%의 Na이 담지된 $Pt/CeO_2$ 촉매의 경우를 제외하고 나머지 Na이 담지된 촉매들은 비교적 높은 CO의 전환율을 나타내었다. 특히 2 wt%의 Na이 담지된 $Pt/CeO_2$ 촉매는 가장 높은 CO의 전환율을 나타내었다. 따라서 Na 담지량의 변화가 포름산염의 C-H결합 분해에 영향을 미친다는 것을 알 수 있다.

• Carbon letters
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• 제11권4호
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• pp.336-342
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• 2010

Different oxidation treatments on CNTs using diluted 4.0 M $H_2SO_4$ solution at room temperature and or at $90^{\circ}C$ reflux conditions were investigated to elucidate the physical and chemical changes occurring on the treated CNTs, which might have significant effects on their performance as catalyst supports in PEM fuel cells. Raman spectroscopy, X-ray diffraction and transmission electron microscope analyses were made for the acid treated CNTs to determine the particle size and distribution of the CNT-supported Pt-Ru nanoparticles. These CNT-supported Pt-based nanoparticles were then employed as anode catalysts in PEMFC to investigate their catalytic activity and single-cell performance towards $H_2$ oxidation. Based on PEMFC performance results, refluxed Pt-Ru/CNT catalysts prepared using CNTs treated at $90^{\circ}C$ for 0.5 h as anode have shown better catalytic activity and PEMFC polarization performance than those of the commercially available Pt-Ru/C catalyst from ETEK and other Pt-Ru/CNT catalysts developed using raw CNT, thus demonstrating the importance of acid treatment in improving and optimizing the surface properties of catalyst support.

• Journal of Applied Biological Chemistry
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• 제63권4호
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• pp.357-363
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• 2020

Oxidative stress caused by the overproduction of reactive oxygen species (ROS) is known as an etiology of neurodegenerative diseases. Populus tomentiglandulosa (PT), a member of the Salicaceae family, is widely grown in Korea and has been reported to exert protective effects on cerebral ischemia by attenuating of oxidative stress and neuronal damage. In the present study, we investigated the antioxidant activity and neuroprotective effects of an ethanol extract and four fractions [n-butanol, ethyl acetate (EtOAc), chloroform, and n-hexane] of PT under in vitro and cellular systems. The extract and four fractions of PT showed 1,1-diphenyl-2-picrylhydrazyl (DPPH), •OH, and O2- radical scavenging activities in a dose-dependent manner. In particular, the EtOAc fraction of PT had the strongest DPPH, •OH, and O2- radical scavenging activities among the extract and other fractions. Therefore, we further investigated the neuroprotective effect of the EtOAc fraction of PT against oxidative stress in H2O2-induced SH-SY5Y cells. Treatment with H2O2 significantly decreased cell viability and lactate dehydrogenase (LDH) release, and it also increased the ROS levels compared to the normal group. However, treatment with the EtOAc fraction of PT significantly increased cell viability. Moreover, the EtOAc fraction of PT-treated group significantly suppressed ROS production and LDH release compared to the H2O2-induced control group. In conclusion, our findings indicated that PT had in vitro antioxidant activity and neuroprotective effects against oxidative stress. Therefore, PT could be used as a natural agent for protection against oxidative stress.

• 융복합기술연구소 논문집
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• 제10권1호
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• pp.19-24
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• 2020

The purpose of the study is to investigate the thermal durability characteristics of the Pt catalyst and additives used in a catalytic combustor. The catalyst used in the experiment was based on Pt (3 wt%), and a total of 12 types were prepared using a combination of additives (Ni, La, Ce, Fe, and Co). From the results, In the fresh state, the two types of combination catalysts with the highest C₃H₈ conversion were Pt_Ce (79.9%) at 500℃, and in the three types of combination catalysts, Pt_La_Ni (93.4%) at 500℃ had the best performance. Among aged catalysts at 850℃ and 8 hours, Pt-La-Ni and Pt-Ni-Ce catalysts showed the highest C₃H₈ conversion of about 71% at 500℃.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권2호
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• pp.69-75
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• 1999

The characteristics of $H_2$ gas detection have been investigated using the Pt-MIS capacitor composed of the LPCVD nitride on the oxide. The flat band voltage shift is measured as 0.1 V in 1,000 ppm $H_2$ gas ambient and to be independent of Pt catalyst thickness. It is found that the flatband voltage shift is proportional to the hydrogen concentrations. The response and recovery time of Pt-MIS capacitor are 5 mins and 25 mins respectively. The samples of 30nm thick Pt revealed much higher sensitivity than that of 150nm samples. The samples of 150nm Pt showed that the flatband voltage shift of the device is due to the formation of the dipole layer of the adsorbed hydrogen atoms at the Pt-insulator interface.