• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.365-371
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• 2017

Hydrogen has potential for preventive and therapeutic applications as an antioxidant. However, micro- and macroparticles of hydrogen in water disappear easily over time. In order to eliminate reactive oxygen species (ROS) related with the aging process, we used functional water containing nanoparticle hydrogen. Nanoparticle hydrogen does not disappear easily and collapse under water after long periods of time. We used murine embryonic fibroblasts that were isolated from 12.5-day embryos of C57BL/6 mice. We investigated the ability of nanoparticle hydrogen in water to suppress hydroxyurea-induced ROS production, cytotoxicity, and the accumulation of ${\beta}-galactosidase$ (an indicator of aging), and promote cell proliferation. The accumulation of ${\beta}-galactosidase$ in the cytoplasm and the appearance of abnormal nuclei were inhibited by daily treatment of cells with hydrogen water. When the aging process was accelerated by hydroxyurea-induced oxidative stress, the effect of hydrogen water was even more remarkable. Thus, this study showed the antioxidant and anti-senescence effects of hydrogen water. Nanoparticle hydrogen water is potentially a potent anti-aging agent.

• 한국전산유체공학회지
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• 제15권2호
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• pp.47-54
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• 2010

In the present study, a numerical simulation for the diffusion of hydrogen leakage of FCV(Fuel Cell Vehicle) in a tunnel was performed to aid the assessment of risk in case of leakage accident. The temporal and spatial distributions of the hydrogen concentration around FCV are predicted from the present numerical analyses. Flammable region of 4-74% and explosive region of 18-59% hydrogen by volume was identified from the present results. Factors influencing the diffusion of the hydrogen jet were examined to evaluate the effectiveness of tunnel ventilation system for relieving the accumulation of the leaked hydrogen gas. The distribution of the concentration of the leaked hydrogen for various cases can be used as a database in various applications for the hydrogen safety.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.477-482
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• 2011

In the present study, the diffusion process of hydrogen leaking from a FCV (Fuel Cell Vehicle) in an underground parking lot was analyzed by numerical simulations in order to assess the risk of a leakage accident. The temporal and spatial changes of the hydrogen concentration as well as the flammable region in the parking lot were predicted numerically. The effects of the leakage flow rate and an additional ventilation fan were investigated to evaluate the ventilation performance in the parking lot to relieve the accumulation of the leaked hydrogen gas. The present numerical analysis can provide useful information such as the distribution of the leaked hydrogen concentration for safety of various hydrogen applications.

• 분석과학
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• 제10권2호
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• pp.119-125
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• 1997

미량의 루테늄(III)을 간편하게 정량할 수 있는 벗김 전압-전류법을 제시한다. 흡착 누적에 의한 사전 농축과 루테늄의 전극 촉매작용을 효과적으로 이용하여 큰 촉매 전류를 얻기 위한 최적 조건은, 아세트산 완충 용액의 농도 0.01M, pH 2.0, 히드라진 농도 0.01M, 그리고 누적 전위 -0.76V 등이다. 적정 누적 시간은 농도에 따라 다르나 2~10분이면 무난하다. 이 조건에서 검출 한계는 $7{\times}10^{-9}M$(2분) 또는 $2{\times}10^{-9}M$(7분)이었다.

• Journal of Welding and Joining
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• 제8권3호
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• pp.39-52
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• 1990

The research is to insure the soundness of the stainless steel overlaid weld metal(21/4Cr-IMo steel + SUS 309L) for a pressure vessel application. Detail studies were conducted for the PWHT influence on the micrstructure and intergranular corrosion characteristics of the overlaid weld metal as well as initiation of hydrogen embrittlement crack(or Disbonding) when welded metal are exposed to the hydrogen atmosphere. Hydrogen was experimentally charged to the overlaid weld metal in order to study PWHT effect on the susceptibility of hydrogen embrittlement crack. The results of this research are as follows: 1. At the bond region, austenite grain of the stainless steel side became coarsed and Cr23C6 type carbide was precipitated at the coarsed austenitic grain boundaries. Intergranular Corrosion width(by Straiss test) increased with increasing PWHT temperature and PWHT time.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 춘계학술대회논문집
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• pp.176-182
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• 2009

In the present study, a numerical simulation for the diffusion of hydrogen jet in a enclosure was performed to aid the leakage test of the hydrogen for the safety of the hydrogen vehicle. The temporal and spatial distributions of the hydrogen concentration in the test chamber are predicted from the present numerical analyses. Flammable region of 4-74% and explosive region of 18-59% hydrogen by volume was identified from the present results. Factors influencing the diffusion of the hydrogen jet were examined to evaluate the effectiveness of forced ventilation for relieving the accumulation of the leaked hydrogen gas in the chamber, which include location of open windows, size of leakage nozzle, and leakage rate among others. The distribution of the concentration of the leaked hydrogen for various cases can be used as a database in various applications for the hydrogen safety.

• 한국전산유체공학회지
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• 제14권2호
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• pp.32-38
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• 2009

In the present study, a numerical simulation for the diffusion of hydrogen jet in a enclosure was performed to aid the leakage test of the hydrogen for the safety of the hydrogen vehicle. The temporal and spatial distributions of the hydrogen concentration in the test chamber are predicted from the present numerical analyses. Flammable region of 4-74% and explosive region of 18-59% hydrogen by volume was identified from the present results. Factors influencing the diffusion of the hydrogen jet were examined to evaluate the effectiveness of forced ventilation for relieving the accumulation of the leaked hydrogen gas in the chamber, which include location of open windows, size of leakage nozzle, and leakage rate among others. The distribution of the concentration of the leaked hydrogen for various cases can be used as a database in various applications for the hydrogen safety.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.277-280
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• 2000

수소 생산량은 기질로부터 생산될 수 있는 수소의 분자수와 균주간의 특성에 의해서 좌우된다. 광합성 세균에 의한 수소 가스 생산은 유기물질 및 물을 전자 공여체로 하여 광합성에 의해 생산되는 것으로 알려져 있다. 이론적으로 수소생산량은 glucose 한 분자로부터 12분자의 수소가스가 생산된다.

• Corrosion Science and Technology
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• 제2권3호
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• pp.109-116
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• 2003

It is well known that SSCC (sulfide stress corrosion cracking) is caused by drastic ingression of hydrogen during the service and accumulation of hydrogen near the potential crack initiation site in the material. It is important to characterize the hydrogen trapping behavior to evaluate the service performance of the high strength pipeline steels. In this study. the relationship between the hydrogen trapping behavior and SSCC susceptibility is evaluated in terms of alloy composition, microstructure and carbide behavior. The hydrogen trapping behavior was measured by electrochemical hydrogen permeation test cell (Devanathan cell). The SSCC susceptibility is evaluated by constant extension rate test and constant strain lest method. The hydrogen trapping behavior is affected greatly by microstructure and nature of carbide particles. The fine TiC, and NbC in the matrix of ferritic structure acts as strong irreversible trap sites whereas the bainitic structure acts as reversible trap site. The SSCC susceptibility is closely related to not only the hydrogen trapping behavior but also the loading condition. As the activity of reversible trap site increases, SSCC susceptibility decreases under static loading condition below yield strength, whereas SSCC susceptibility increases under dynamic loading condition or above yield strength. As the activity of irreversible trap site increases. SSCC susceptibility increases regardless of loading condition. It is cased by the mixed effect of dislocation on hydrogen diffusion and trapping behavior.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.320-325
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• 2003

Acoustic-Pressure Response of diluted hydrogen-air diffusion flames is investigated numerically by adopting a fully unsteady analysis of flame structures. In the low-pressure regime, the amplification index remains low and constant at low frequencies. As acoustic frequency increases, finite-rate chemistry is enhanced through a nonlinear accumulation of heat release rate, leading to a high amplification index. Finally, the flame responses decrease at high frequency due to the response lag of the transport zone. For a medium-pressure operation and low-frequency excitation, the amplification index is low and constant. It then decreases at moderate frequencies. As frequency increases further, the amplification index increases appreciably due to an intense accumulation effect.