• 한국수소및신에너지학회논문집
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• 제16권1호
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• pp.66-73
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• 2005

Hydrogen linear power system is estimated as the next generation power system which can obtain a performance as same as fuel cell. In order to develop Hydrogen combustion power system with high thermal efficiency, it is very important to understand the basic characteristics of hydrogen combustion and establish combustion stabilization technique of its system. In this study, RICEM(Rapid Intake Compression Expansion Machine) for researching of hydrogen combustion linear power system was manufactured and evaluated, and the basic characteristics of linear RICEM were analyzed.

• 신재생에너지
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• 제19권3호
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• pp.1-12
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• 2023

This study aims to evaluate the optimal size of the hydrogen facility to be installed in a zero-energy district in terms of load matching and facility efficiency. A mismatch between energy generation and consumption is a common occurrence in zero-energy districts. This mismatch adversely effects the energy grid. However, using an energy carrier such as hydrogen can solve this problem. To determine the optimal size of hydrogen fuel cells to be used on-site, simulation of hydrogen installation is required at both district-and building- levels. Each case had four operating schedules. Therefore, we evaluated eight scenarios in terms of load matching, heat loss, and facility operational efficiency. The results indicate that district-level installation of hydrogen facilities enables more efficient energy use. Additionally, based on the proposed model, we can calculate the optimal size of the hydrogen facility.

• 대한본초학회지
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• 제26권2호
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• pp.17-23
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• 2011

Objectives : This study aims at examining the effect of the fermentative extract of root of Sophorae Radix on the immuno-modulating activity. Methods : Cell viabilities were measured by MTT assay. Effect of SFS on nitric oxide(NO), hydrogen peroxide production from RAW 264.7 cells was accessed by Griess reagent assay. Effect of SFS on productions of inflammatory cytokines such as TNF-${\alpha}$, IL-6 in LPS-induced RAW 264.7 cells was accessed by a multiplex bead array assay based on xMAP technology. Results : The results of the experiment are as follows. 1. As a result of carrying out MTT assay to check the cellular toxicity of the fermentative extract of Sophorae Radix. There was not any excessive toxicity to the macrophage when the fermentative extract of root of Sophorae Radix was treated in different concentrations. 2. The fermentative extract of Sophorae Radix increased the generation of hydrogen peroxide in the macrophage and significantly restored the suppression of the generation of the hydrogen peroxide in the macrophage induced by LPS. 3. The fermentative extract of Sophorae Radix reduced the generation of NO in the macrophage and significantly suppressed the increase of the generation of NO in the macrophage induced by LPS. 4. The fermentative extract of Sophorae Radix significantly decreased the amount of TNF-${\alpha}$ generated in the macrophage induced by LPS when it was $25{\mu}g/mL$ or higher. Conclusion : These results suggest that SFS has anti-inflammatory moiety related with its inhibition of NO, hydrogen peroxide, TNF-${\alpha}$, IL-6, in macrophage led by LPS.

• 한국가스학회지
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• 제27권4호
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• pp.85-91
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• 2023

본 연구에서는 GT24 가스터빈의 1단 연소기인 EV버너를 대상으로 수소연료 혼소에 대한 화염거동, 연소 진동 및 NOx 배출 특성에 대한 실험적 연구를 수행하였다. 수소 혼소율이 증가할수록 NOx 배출 농도가 증가하는 결과를 확인하였다. 이러한 변화는 연료 밀도 변화로 인한 침투깊이 변화, 화염전파속도 증가에 따른 화염위치 변화에 기인한 연료 혼합도 감소와 연소진동으로 인한 시간적 혼합도 섭동 영향이 복합적으로 작용한 결과로 판단되었다. 1.3~3.1bar 범위의 가압 시험을 통해 고압 운전 조건의 NOx 배출 특성을 예측하고 이를 토대로 천연가스용 EV 버너의 수소혼소 한계를 평가하였다.

• 한국수소및신에너지학회논문집
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• 제28권6호
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• pp.721-728
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• 2017

In this work, an one-dimensional analysis on spontaneous combustion in a coal stockpile was conducted using a commercial software $gPROMS^{(R)}$ based on assumption suggested by Arioy and Akgun. According to them, it is assumed that there is temperature difference between the surface of coal particle and the gas surrounded around the particle, and it is also assumed that the velocity of the gas is constant and thus oxygen is fed to the stockpile with same velocity. The higher temperature zone is formed to the surface of the coal stockpile at the initial phase and it became deepen as time is taken. Finally it was found that the temperature difference between coal particle and the gas was calculated as $57^{\circ}C$ and spontaneous combustion have not been occurred during 6 months since coal was piled in the stock.

• 한국수소및신에너지학회논문집
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• 제22권6호
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• pp.913-924
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• 2011

A steady-state analysis has been conducted to predict the behavior of the slag layer in the entrained-flow slagging coal gasifier. The analysis takes into consideration the composition dependent slag properties such as density, viscosity, heat capacity, thermal conductivity, and temperature of critical viscosity. The amount of added flux to the design coal and the variation of syngas temperature inside the gasifier have been adopted as calculation parameters. The predicted results are the local thickness of the molten and the solid slag layers, and the slag viscosity and the velocity distribution across the molten slag layer along the gasifier wall near the slag tap.

• 한국수소및신에너지학회논문집
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• 제20권5호
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• pp.384-389
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• 2009

KEPRI (Korea Electric Power Research Institute) has studied planar type solid oxide fuel cell (SOFC) stacks using anode-supported cells and kW class co-generation systems for residential power generation. In this work, a 1 kW SOFC system consisted of a hot box part, a cold BOP (balance of plant) part, and a hot water reservoir. The hot box part contained a SOFC stack made up of 48 cells, a fuel reformer, a catalytic combustor, and heat exchangers. Thermal management and insulation system were especially designed for self-sustainable operation in that system. A cold BOP part was composed of blowers, pumps, a water trap, and system control units. When the 1 kW SOFC stack was tested using hydrogen at $750^{\circ}C$, the stack power was about $1.2\;kW_e$ at 30 A and $1.6\;kW_e$ at 50 A. Turning off an electric furnace, the SOFC system was operated using hydrogen and city gas without any external heat source. Under self-sustainable operation conditions, the stack power was about $1.3\;kW_e$ with hydrogen and $1.2\;kW_e$ with city gas respectively. The system also recuperated heat of about $1.1\;kW_{th}$ by making hot water.

• Nuclear Engineering and Technology
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• 제29권2호
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• pp.99-109
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• 1997

A dynamic model for hydrogen generation by Fuel-Coolant Interactions(FCI) is developed with separate models for each FCI stage, coarse mixing and stratification. The model includes the physical concept of FCI, semi-empirical heat and mass transfer correlation and the concentration diffusion equation with the general non-zero boundary condition. The calculated amount of hydrogen, which is mainly generated in stratification, is compared with the FITS experiments. The model developed in this study shows a good agreement within a range of 10 % fuel oxidation rate and predicts the controlled mechanism of the chemical reaction very well. And this model predicts more accurately than the previous works. It is shown from the sensitivity study that the higher initial temperature of fuel particle is, the larger the reaction rate is. Up to 2700 K of temperature of the particle, the reaction rate increases rapid, which can lead to metal ignition.

• 한국수소및신에너지학회논문집
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• 제19권5호
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• pp.460-466
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• 2008

In this study, a computer modeling work has been performed for the power generation system using polymer electrolyte fuel cell with Aspen Plus general purpose chemical process simulator. Stoichiometric reactor module was used for the modeling of reformer for the production of hydrogen. For the modeling of the electrochemical reaction, Gibbs reactor module built-in Aspen Plus was utilized. SRK equation of state model was selected for the proper simulation of the overall fuel cell system.

• 한국수소및신에너지학회논문집
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• 제33권5호
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• pp.507-514
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• 2022

There is growing interest in sustainable energy sources that can reduce fossil fuel dependence and environmental pollution while meeting rapidly growing energy demands. Hydrogen have been investigated as one of the ideal alternative energies because it has relatively high efficiency without emitting pollutants. The light-sensitized enzymatic (LSE) system, which uses hydrogenase-enzymes, is one of the methods towards economically feasible system configurations that enhance the rate of hydrogen generation. Hydrogenase is an enzyme that catalyzes a reversible reaction that oxidizes molecular hydrogen or produces molecular hydrogen from protons and electrons. In this paper, utilization of [NiFe]-hydrogenase (from Pyrococcus furiosus) in photoelectrochemical hydrogen production system such as handling, immobilization, physicochemical and electrochemical analysis, process parameters, etc. was introduced.