• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.3
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• pp.358-370
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• 1997

In the present study, investigations were carried out to obtain data on combustion characteristics of methane gas and hydrogen supplemented methane gas in a constant volume combustion chamber. The main results obtained from the study can be summarized as follows. The maximum combustion pressure increases as the initial pressure and hydrogen supplement rate increase, the total burning time is shorten by lowering the initial pressure and by increasing the hydrogen supplement rate. The maximum flame temperature and NO concentration increase by the initial pressure and hydrogen supplement rate increase. The flame propagation processes in near stoichiometric mixture are propagated with a spherical shape, but in excess rich or lean mixtures are propagated with a elliptical shape. And, they are changed an unstable elliptical shape flame with very regular cells by increasing the hydrogen supplement rate.

• Applied Chemistry for Engineering
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• v.8 no.1
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• pp.84-91
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• 1997

Diamond film was deposited on Mo substrate at atmospheric pressure using a combustion flame apparatus with the addition of $H_2$. With the substrate temperature, the nucleation density of the substrate was increased. At temperatures above $1000^{\circ}C$, some of diamond was partly converted into graphite and etched by hydrogen atoms. With an increase of the $C_2H_2/O_2$ ratio, the nucleation density was increased. But crystals were cauliflower-shaped and a large number of amorphous carbon were deposited. With the addition of $H_2$, the nucleation density of diamond was increased by the improvement of surface activity. Diamond film of high crystallinity was deposited by etching amorphous carbon. With an increase of deposition time, the thickness of diamond film was increased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.132-135
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• 2004

현재 사용 되고 있는 Cu CMP slurry에서 pH 적정제의 역할은 slurry의 연마 거동을 결정 하는 중요한 요소이다. 일반적으로 사용 되고 있는 적정제로는 $NH_4OH$, KOH가 있다. 구리 CMP용 슬러리내에서 CMP 공정 중에 과산화수소 $(H_2O_2)$의 영향에 관한 연구는 있으나, 과산화수소의 농도 (vol %) 변화에 따라서 pH적정제가 하는 역할과 반응이 CMP 공정중에 미치는 영향에 관해서 연구된 바 없다. 이 논문에서는 pH 적정제가 과산화수소의 농도에 따라서 산성, 중성, 염기성에서 어떠한 변화를 일으키는지에 관해서 dynamic etch rate과 removal rate을 비교 하였고, static etch rate을 이용하여 Cu 표면이 etching 되는 속도를 비교 하였다. 그 결과, 산성과 중성에서는 $NH_4OH$와 KOH의 경향성은 비슷하였으나, 염기성에서는 KOH를 첨가한 경우 변화가 나타나지 않았다. 따라서, pH가 염기성으로 갈수록 과산화수소의 저 농도에서 $NH_4OH$의 영향이 더 커짐을 알 수 있었다.

• Clean Technology
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• v.21 no.4
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• pp.271-277
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• 2015

A photocatalyst which mixed by the commercialized P25-TiO₂ and a synthesized Ag_xO was used in an appropriate weight ratio to effectively produce hydrogen gas in this study. The Ag_xOs were synthesized with the conventional sol-gel method, and tetramethylammonium hydroxides were added at the synthesis process in order to stabilize the solutions, and then the solutions were heat-treated at the temperatures of -5, 25, and 50 ℃, resulted to obtain the three types of silver oxides. Physicochemical properties of the synthesized Ag_xOs were identified through X-ray diffraction analysis (XRD), scanning emission microscopy (SEM), ultraviolet-visible spectroscopy, and X-ray photoelectron spectroscopy (XPS). In the photolysis results of water/methanol (weight ratio 1:1) solution, the mixture of P25-TiO₂/Ag_xO exhibited a significantly higher hydrogen gases evolution, compared to that of pure P25-TiO₂. Additionally, the addition of H₂O₂ as an supplement oxidant and in Ag_xO synthesized at 50 ℃ improved the hydrogen production efficiency. In particular, the emitted hydrogen gases reached to 13,000 μmol during 8 hours when a mixed catalyst, Ag_xO of 0.1 g and P25-TiO₂ of 0.9 g, were used.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.5
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• pp.377-385
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• 2008

In this study, we demonstrated that, although hydrogen molecules can be adsorbed onto the adsorbent such as MOF and MC itself, the loading of noble metal such as Pt is necessary to enhance the $H_2$ storage capacity since $H_2$ molecules can be dissociatively adsorbed on Pt metal and migrated to high-surface-area adsorbent via the primary spillover. In addition, the hybrid material have been prepared coupling MOF-5 with Pt/MC through carbon bridges formed by sucrose polymerization/carbonization. That this material showed the highest $H_2$ uptake at room temperature and about 100 bar is believed to be associated with the secondary spillover effect. Thus, such a strategy is very promising in developing $H_2$ storage technology using porous adsorbents. However, further experiments should be carried out to explore the choice of bridge carbon, the hybridization method, the dispersion technique of noble metals, etc.

• Journal of the Korean Chemical Society
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• v.37 no.2
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• pp.199-205
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• 1993

The decomposition of hydrogen peroxide by copper-amines complexes was studied in the pH range of 7.3∼11.3 by measuring the rate of the decreasing concentration of $H_2O_2$. Decomposition rate of hydrogen peroxide increased with increasing pH, and then decreased with increasing pH successively. The mechanism for this type of reaction involves the formation of peroxo complexes in the rate-determining step preceding deprotonation of hydrogen peroxide and copper-amines complexes.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1997.05a
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• pp.92-96
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• 1997

고농도로 오염된 난분해성 유해오염물질은 토양계에 존재하고 있는 미생물에 대한 독성과 낮은 활성도로 인하여 복원기술 발전에 제한되어진다. 본 연구에서는 pH 4.8과 pH 7.7인 토양에 Phenanthrene을 인위적으로 오염시킨후 heme 촉매와 과산화수소를 이용하여 오염토양을 복원하는 기술에 대한l 기초적 연구를 수행하였다. Heme과 과산화수소를 오염토양에 첨가한 뒤 30일 반응후 토양내 존재하고 있는 Phenanthrene 초기농도 약 400 mg/kg soil에 대한 분해율은 pH 4.8과 7.7 오염토양내 각각 50％와 67%이었다. Heme과 과산화수소를 이용한 오염토양의 복원기술은 중성 오염토양에서 약 3일후 67％ 빠르게 분해되는 결과를 보여주고 있다.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.1
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• pp.35-41
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• 2011

Temperature programmed reduction experiments for Fe- and Co-oxides were performed and weight losses were carefully measured to calculate the extent of reduction. Addition of nickel and palladium affected the reduction by lowering the DTG peak temperature. Reduction experiments for the oxides on alumina were also studied and the effect of nickel and palladium addition was confirmed. And that was explained by means of increased adsorption of hydrogen and increased diffusion ability of the surface hydrogen.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.48-49
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• 2008

유도결합플라즈마를 적용한 화학기상증착법으로 $TiO_2$ 박막을 얻었다. 박막의 특성 조절을 위해 수소유량을 변화시켰다. 수소 유량을 증가시킴에 따라 박막의 표면 형상, 결정성, 결정 구조 및 광촉매 특성이 변하였다. 고밀도 플라즈마가 반응 기체의 분해를 촉진함으로써 외부 가열없이 아나타제 $TiO_2$가 만들어졌다. 적절한 양의 수소를 첨가했을 때, 루타일 상으로 상전이가 발생하였다. 화학기상증착법에서 루타일 $TiO_2$는 일반적으로 900 K 이상의 고온에서 형성되는 것으로 알려져 있다. 수소의 역할을 고찰하기 위해 랭뮤어 탐 침법과 발광 분광기를 이용한 플라즈마 진단을 수행하였다.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.231-236
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• 1997

방사성물질의 수송 및 저장용기 등에 사용되는 실리콘고무계 및 수소 첨가된 비스페놀-A형 에폭시수지계 중성자 차폐재들의 인장강도, 압축강도, 비중, 무게, 수소함량 등에 방사선이 미치는 영향을 검토하였다. 방사선 조사선량의 증가에 따라 실리콘고무계 중성자 차폐재(KNS-101 및 102)들의 인장강도, 압축강도, 비중 등이 증가하는 경향을 나타내었으며, 차폐재의 무게는 거의 변화가 없었으나, 수소함량은 약간 감소하는 경향을 나타내었다. 또한 에폭시수지계 중성자 차폐재(KNS-201 및 202)들의 인장강도 및 압축강도는 0.1 MGy까지는 방사선 조사선량의 증가에 따라 증가하다가 0.1MGy 이상에서는 감소하는 경향을 나타내었으며, 조사선량의 증가에 따른 차폐재들의 비중, 무게 및 수소함량은 크게 변하지 않는 것으로 나타났다.