• Title/Summary/Keyword: Hydrogen content

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Preparation and Characterization of Fe-Ni-Pt Nanocatalyst for Anion Exchange Membrane in Alkaline Electrolysis (음이온 교환막 수전해용 Fe-Ni-Pt 나노촉매 제조 및 특성)

  • JAEYOUNG LEE;HONGKI LEE
    • Journal of Hydrogen and New Energy
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    • v.34 no.5
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    • pp.421-430
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    • 2023
  • Fe-Ni-Pt nanocatalysts were loaded on carbon black powders which were synthesized by a spontaneous reduction reaction of iron (II) acetylacetonate, nickel (II) acetylacetonate and platinum (II) acetylacetonate. The morphology and the loading weight of Fe-Ni-Pt nanoparticles were characterized by transmission electron microscopy and thermogravimetric analyzer. The amount of Fe-Ni-Pt catalyst supported on the carbon black surface was about 6.42-9.28 wt%, and the higher the Fe content and the lower the Pt content, the higher the total amount of the metal catalyst supported. The Brunauer-Emmett-Teller Analysis (BET) specific surface area of carbon black itself without metal nanoparticles supported was 233.9 m2/g, and when metal nanoparticles were introduced, the specific surface area value was greatly reduced. This is because the metal nanocatalyst particles block the pore entrance of the carbon black, and thereby the catalytic activity of the metal catalysts generated inside the pores is reduced. From the I-V curves, as the content of the Pt nanocatalyst increased, the electrolytic properties of water increased, and the activity of the metal nanocatalyst was in the order of Pt > Ni > Fe.

Role of Nitric Oxide as an Antioxidant in the Defense of Gastric Cells (위선세포의 항산화 방어기전으로의 Nitric Oxide의 역할)

  • Kim, Hye-Young;Lee, Eun-Joo;Kim, Kyung-Hwan
    • The Korean Journal of Pharmacology
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    • v.32 no.3
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    • pp.389-397
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    • 1996
  • Gatric mucosa is exposed to toxic, reactive oxygen species generated within the lumen. Nitric oxide protected acetaminophen-induced hepatotoxicity by maintaining glutathione homeostasis. The present study examined the role of nitric oxide in mediating hydrogen peroxide - induced damage to gastric cells. Hydrogen peroxide was generated by glucose oxidase acting on ${\beta}-D-glucose$. L-arginine, $N^G-nitro-L-arginine$ methyl ester, or $N^G-nitro-L-arginine$ were treated to the cells with glucose/glucose oxidase. Lipid peroxidation and nitrite release and cellular content of glutathione were determined. As a result, dose - dependent increase in lipid peroxide production as well as dose - dependent decrease in nitrite release and cellular glutathione content were observed in glucose/glucose oxidase - treated cells. Pretreatment of L-arginine, a substrate for nitric oxide synthase, prevented the increase of lipid peroxide production and the reduction of nitrite release as well as glutathione content. Inhibitors of nitric oxide synthase such as $N^G-nitro-L-arginine$ methyl ester and $N^G-nitro-L-arginine$ did not protect hydrogen peroxide - induced cell damage. In conclusion, nitric oxide protects gestric cells from hydrogen peroxide possibly by inhibiting lipid peroxidation and by preserving cellular glutathione stores.

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Development of Synthesis Process for Ammonia Borane using NaBH4 as the Hydrogen Storage Materials (NaBH4를 이용한 암모니아 보란 수소 저장 소재 합성 공정 개발)

  • Choi, Ho Yun;Park, Sung Jin;Jung, Sung Jin;Baek, Jong Min;Song, Han Dock;Kim, Jong Soo;Lee, Kun Jong;Kim, Young Lae
    • Journal of Hydrogen and New Energy
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    • v.25 no.5
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    • pp.475-481
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    • 2014
  • Ammonia borane ($NH_3BH_3$), as a source material for energy generation and hydrogen storage, has attracted growing interest due to its high hydrogen content. We have investigated the synthesis of ammonia borane from sodium borohydride ($NaBH_4$) and ammonium chloride ($NH_4Cl$) utilizing a low-temperature process. From our results, we obtained a maximum synthetic yield of 98.2% of ammonia borane complex. The diammoniate diborane (DADB) was detected in about 5~10mol% with in the solid ammonia borane by solid-state $^{11}B$-NMR analysis. The synthesized solid ammonia borane products were studied to characterize hydrogen release upon thermal dehydrogenation.

Effect of Dissolved Hydrogen on Fuel Crud Deposition (핵연료 피복관 부식생성물 부착에 대한 용존수소의 영향)

  • Baek, S.H.;Kim, U.C.;Shim, H.S.;Lim, K.S.;Won, C.H.;Hur, D.H.
    • Corrosion Science and Technology
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    • v.13 no.2
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    • pp.56-61
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    • 2014
  • The purpose of this work is to investigate the effect of dissolved hydrogen concentration on crud deposition onto the fuel cladding surface in the simulated primary environments of a pressurized water reactor. Crud deposition tests were conducted in the dissolved hydrogen concentration range of 5~70 cc/kg at $325^{\circ}C$ for 14 days. Needle-shaped NiO deposits were formed in the hydrogen range of 5~25 cc/kg, while polygonal nickel ferrite deposits were observed at a hydrogen concentration above 35 cc/kg. However, the dissolved hydrogen content seems to have little effect on the amount of crud deposits.

Hydriding Performance in a Uranium Bed depending on the Initial Bed Temperatures and Helium Contents (우라늄 베드 초기온도 및 헬륨농도의 수소 흡장 영향)

  • KOO, DAESEO;KIM, YEANJIN;JUNG, KWANGJIN;YUN, SEI-HUN;CHUNG, HONGSUK
    • Journal of Hydrogen and New Energy
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    • v.27 no.2
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    • pp.163-168
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    • 2016
  • Korea has been developing nuclear fusion fuel storage and delivery system (SDS) technologies including a basic scientific study on hydrogen storage. To develop nuclear fusion technology, it is necessary to store and supply hydrogen isotopes needed for Tokamak operation. SDS is used for storing hydrogen isotopes as a metal hydride form. The rapid hydriding of tritium is very important not only for safety reasons but also for the economic design and operation of the SDS. In this study, we designed and fabricated a medium-scale getter bed of depleted uranium (DU). The hydriding of DU has been measured by varying the initial temperature ($100-300^{\circ}C$) of the DU getter bed to investigate the influence of the cooling temperature. Furthermore, we analyzed the effect of a helium blanket on the hydriding performance with 0 - 12% helium content in hydrogen.

Modification of Hydrogen Determinator for Total Hydrogen Analysis in Irradiated Zircaloy Cladding Tube (수소분석기 개조 및 조사후 지르칼로이 피복관의 총수소분석)

  • Park, Soon-Dal;Choi, Kwang-Soon;Kim, Jong-Goo;Joe, Kih-Soo;Kim, Won-Ho
    • Analytical Science and Technology
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    • v.12 no.6
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    • pp.490-497
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    • 1999
  • A hydrogen determinator was modified and installed in the glove box to analyse total hydrogen content in irradiated zircaloy tube. The analysis method of hydrogen is Inert Gas Fusion(IGF)-Thermal Conductivity Detection(TCD). The hydrogen recoveries of no tin method using Ti and Zr matrix standards, respectively, were available within $3{\mu}g$ of hydrogen. Also the smaller size of sample showed the better hydrogen recovery. It was found that the hydrogen standard of Ti matrix is avaliable to hydrogen analysis in zircaloy sample. The mean radioactivity of irradiated zircaloy sample was 10 mR/hr and hydrogen concentration was 130 ppm.

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