• 한국전기화학회:학술대회논문집
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• 2004.06a
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• pp.121-124
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• 2004

• Journal of The Korean Society of Clinical Toxicology
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• v.2 no.2
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• pp.147-150
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• 2004

Hydrogen sulfide is a colorless, and malodorous 'rotten eggs' gas that results from the decay of organic material. It is a byproduct of industry and agriculture. The mechanism of its toxicity is primarily related to inhibition of oxidative phosphorylation, which causes a decrease in available cellular energy. Because there is no rapid method of detection that is of clinical diagnostic use, management decisions must be made based on history, clinical presentation, and diagnostic tests that imply hydrogen sulfide's presence. Although there is some anecdotal evidence to suggest that the early use of hyperbaric oxygen is beneficial, supportive care remains the mainstay of therapy. We describe an occupational exposure to hydrogen sulfide gas in 51-year-old man. While cleaning the sewage of pigs. he became unconscious. When he arrived in the emergency department, he had irritability and confused mentality. The typical smell of rotten eggs on clothing and exhaled air were enough to be considered to be exposed to hydrogen sulfide. Hyperbaric oxygen therapy was performed. He had a recovery to normal function.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.1
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• pp.1-9
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• 2008

Human has faced in lack of fossil fuel and environmental crisis because of high population growth and development of industry. Hydrogen, unlimited amount and clean resource from water electrolysis, is remarkably known as the solution of recent energy crisis. One of the special characteristics of hydrogen is that a little amount of catalytic such as platinum and palladium makes nonflammable combustion, in other words catalyst combustion. Catalytic combustion fueled by hydrogen is environmentally friendly. This paper considers some comparisons of characteristic of catalytic combustion between a single layer of platinum catalyst, double layer of platinum and nickel catalysts and mixture of platinum and nickel catalysts. Some experiments of temperature distribution at different positions and characteristic of combustion in low temperature region were done in order to find an applicable possibility as a house-cooking burner.

• Nuclear Engineering and Technology
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• v.51 no.7
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• pp.1749-1757
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• 2019

Predicting lower flammability limits (LFL) of hydrogen has become an ever-important task for safety of nuclear industry. While numerous experimental studies have been conducted, LFL results applicable for the harsh environment are still lack of information. Our aim is to develop a calculated non-adiabatic flame temperature (CNAFT) model to better predict LFL of hydrogen mixtures in nuclear power plant. The developed model is unique for incorporating radiative heat loss during flame propagation using the CNAFT coefficient derived through previous studies of flame propagation. Our new model is more consistent with the experimental results for various mixtures compared to the previous model, which relied on calculated adiabatic flame temperature (CAFT) to predict the LFL without any consideration of heat loss. Limitation of the previous model could be explained clearly based on the CNAFT coefficient magnitude. The prediction accuracy for hydrogen mixtures at elevated initial temperatures and high helium content was improved substantially. The model reliability was confirmed for $H_2-air$ mixtures up to $300^{\circ}C$ and $H_2-air-He$ mixtures up to 50 vol % helium concentration. Therefore, the CNAFT model developed based on radiation heat loss is expected as the practical method for predicting LFL in hydrogen risk analysis.

• Journal of Digital Policy
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• v.1 no.2
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• pp.47-52
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• 2022

The absolute dependence on GPS signals for positioning, unstable flight, and short flight time due to battery limitations are the major problems to extend the practical use of drones in the industry. In particular, the short flight time of about 20 minutes is a big issue to the use of drones, and to overcome this, the liquid hydrogen powered drone is being actively developed. However, the revision of the current regulation and certification system for liquid hydrogen powered drone has not been completed yet, making it difficult to test, certify, and commercialize the hydrogen powered drone, which eventually becomes a problem in pre-occupying the increasing drone market. In this paper, we analyze the development trends of hydrogen powered drone and provide the current issues on regulations and certification systems for hydrogen powered drone.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1361-1362
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• 2007

There is great interest in the applicability of electrogenerated hydrogen peroxide to a wide variety of industrial processes, usually involving oxidation of organics. Hydrogen peroxide is now employed for the bleaching of mechanical pulp and the bleaching of chemical pulp in the pulp and paper industry, thus displacing the traditional alkaline treatments with chlorine-based chemicals. This psper reperts a comparative study of $H_{2}O_{2}$ electogeneration on gas-diffusion electrode in divided cell with several $Nafion^{(R)}$ protonexchange membranes, Russian cation-exchange membrane MK-40 and SPEEK membrane. The influence of different PEMs on electrochemical cell voltage, current efficiency and energy consumption of hydrogen peroxide electrogeneration has been stadied.

• Mass Spectrometry Letters
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• v.2 no.1
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• pp.1-7
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• 2011

China's rapid economic growth has resulted in significant environmental side effects. Therefore, China has been interested in reducing her dependence on foreign oil and gas by developing technologies needed for hydrogen, in addition to her increasing energy mix of nuclear and renewable energy form, such as solar and wind power. There are three isotopes of hydrogen, i.e. protium (P or H), deuterium (D), and tritium (T). Both deuterium and tritium are important materials in nuclear fuel cycle industry. Tritium is one of the critical radioactive nuclides. Planning for and implementing contamination control as a part of normal operation and maintenance activities is an important function in any hydrogen facility, especially tritium facility. The development of hydrogen isotopes analysis is the key issues in this area. Mass spectrometry (MS) with medium (about 600) and high resolution (> 1,400) is commercially available; however, the routine analysis of hydrogen isotopes is done with low-resolution MS (< 200) in China. This paper summarizes the progress of MS measurement technology for hydrogen isotope abundance in China, focusing on our lab's research program and technical status. An analyzing method has been introduced for accurate measurement of tritium abundance in the H.D.T system by low resolution MAT-253 MS. The quotient of compression ratio coefficient is determined by building up equipment for laboratory-scale preparation of secondary standard gases and by considering the difference in sensitivity between hydrogen isotopes. The results show that the measured value is reproducible within the relative error range of 0.8% for gas samples of different tritium abundance.

• Journal of the Korean institute of surface engineering
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• v.51 no.5
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• pp.277-290
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• 2018

In this study, Pd-Ni-Ag alloy hydrogen separation membranes were fabricated by Pd/Ag/Pd/Ni/Pd multi-layer sputter deposition on the modified MIM(Metal Injection Molding)-PSS(Porous Stainless Steel) support and followed heat treatment. Nickel, used as an alloying element in Pd alloy membranes, is inexpensive and stable material in a hydrogen isotope environment at high temperature up to 1123 K. Hydrogen perm-selectivity of Pd-Ni-Ag alloy membranes is affected not only by composition of membrane films but also by other factors such as surface properties of PSS support, microstructure of membrane films and inter-diffused impurities from PSS support. In order to clarify the effect of surface Ni composition on hydrogen perm-selectivity of Pd-Ni-Ag alloy membranes, the other effects were significantly minimized by the formation of dense and homogeneous Pd-Ni-Ag alloy membranes. Hydrogen permeation test showed that hydrogen permeability decreased from $7.6{\times}10^{-09}$ to $1.02{\times}10^{-09}mol/m{\cdot}s{\cdot}Pa^{0.5}$ as Ni composition increased from 0 to 16 wt% and the selectivity for $H_2/N_2$ was infinite.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.4
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• pp.49-57
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• 1999

In CLO2 delignification and bleaching process, formation of chlorate corresponds to a loss of 20-36% of the original CKO2 charge. Because chlorate is inactive and harmful to environmental, it will be of benefit to find methods that can reduce the formation of chlorate during chlorine dioxide bleaching. Chlorate is mainly formed by the reaction HCIO +ClO2 $\longrightarrow$H+ + Cl_ +ClO3-2 On the other hand, AOX in chlorine dioxide bleacing is formed also due to the in-situ produced hypochlorous acid. THus both AOX and chlorate could be reduced by addition of hypochlorous acid. Some paper son the reduction of AOX by additives appeared , but systematic data on chlorate reduction as well as pulp and effluent properties are not available. THus this paper of focused on the effects on the reduction of chlorate and chlorine dioxide bleachability. The additives, fulfamic a챵, AMSO, hydrogen peroxide, oxalic acid were found to eliminate chlorine selectively in chlorine and chlorine dioxide mixture.However, when they were added to bleaching process, sulfamic acid and DMSO showed significant reduction of chlorate formation but hydrogen peroxide and oxalic aicd did not, and significant amount ofhydrogen peroxide was found resided in the bleaching effluent , In addition, sulfamic acid and DMSO decreased the bleaching end ph values while hydrogen peroxide and oxalic acid did not, which also indicated that hydrogen peroxide and oxalic acid were ineffective. The difference might be ascribed to the competitives of hypochlorous acid with lignin, chlorite (CKO2) and additives. Sulfamic acid and DMSO showed better pulpbrightness development but less alkaline extraction efficiency than hydrogen peroxide , oxalic acid and control, which means that insitu hypochlorous acid contributes to the formation of new chromophore structures that can be easily eliminated by alkaline extraction. DMSO decreased the delignification ability of chlorine dioxide due to the elimination of hypochlorous acid, but sfulfamic acid did to because the chlroinated sulfamic acid had stable bleachability. In addition, sulfamic acid, and SMSO shwed decreased color and COD of bleaching effluents, hydrogen peroxide decreased effluent color but not COD content, and oxalic acid had no statistically significant effects. No significant decreases of pulp viocosity were found except for hydrogen peroxide. Based on our results , we suggest that the effectiveness of hydrogen peroxide on the reduction of AOX in literature might be explained by other mechanisms not due to the elimination of hypochlorous acid , but to the direct decomposition of AOX by hydrogen peroxide.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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• pp.31-36
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• 2006

Tritium has been used to directly measure the exchangeable hydrogen in bleached softwood kraft pulp. The hydrogen atoms associated with hydroxyl groups in pulp or with water contained in the pulp can dissociate and exchange with the hydrogen atoms in bulk water. Tritium is a radioactive isotope of hydrogen and behaves almost identically to it. The distribution of tritium between pulp and water ($k_{pw}$) can be easily measured and becomes an index of the protons available fur hydrogen bonding. Bleached kraft pulp was refined in a PFI mill to a range of freenesses. Tritiated water was added and the amount exchanged measured. There was a slight steady increase in $k_{pw}$ until approximately 300 CSF; $k_{pw}$ then rose sharply between 300 CSF and 100 CSF. This rise appears to correlate with FSP. It is likely that the action of refining on the fiber reaches a threshold at about 300 CSF causing the fiber surface to break open creating exponentially more surface area. This theory is visually confirmed through light microscopy. The slow increase in fibrillation of the fibers above 300 CSF correlates with the increase in $k_{pw}$. Beyond the threshold of 300 CSF a dramatic difference in fibrillation is shown, also corresponding with the large increase in $k_{pw}$. The freeness difference around 300 CSF is small, but the change in fiber properties is extreme within this region. This change in properties could lead to sheet breaks and other disruptions when producing products around the threshold. This study leads to a better understanding of how fiber changes during refining, resulting in a practical benefit of target freeness determination. Presently, freeness is selected based on product quality and on some measure of runnability. Yet, there are other considerations, demonstrated by the extreme change in fiber properties around 300 CSF.