금속-세라믹 복합 분리막은 특히 석탄가스화 공정이나 메탄 개질에서 발생되는 혼합가스로부터 수소를 분리하기 위해 개발되어졌다. 수소투과 금속인 팔라듐과 세라믹 지지체로 Y2O3-stabilized ZrO2 (YSZ)를 이용하여 cermet 수소분리막을 제조하였다. 이렇게 제조된 분리막은 팔라듐의 연속상이 잘 발달된 치밀 구조를 보였다. Pd/YSZ 분리막의 수소 투과량은 100% 수소를 흘려 0.5~2 atm에서 측정되었다. 수소 투과량은 450℃, 2 atm에서 0.333 mL/min·㎠를 보였다. 수소 투과 후 분리막의 표면과 단면에서 균열이 형성되었다.

The size of hydrogen molecule is not so small as to invade into the lattice of material, and therefore, hydrogen invades into the material as atom. Hydrogen movement is done by diffusion or dislocation movement in the near crack tip or plastic deformation. Hydrogen appeared to have many effects on the mechanical properties of the Cr-Mo steel alloys. The materials for this study are 1.25Cr-0.5Mo and 2.25Cr-1Mo steels used at high temperature and pressure. The hydrogen amount obtained by theoretical calculation was almost same with the result solved by finite element analysis. The distribution of hydrogen concentration and average concentration was calculated for a flat specimen. Also, finite element analysis was employed to simulate the redistribution of hydrogen due to stress gradient. The calculation of hydrogen concentration diffused into the material by finite element method will provide the basis for the prediction of delayed fracture of notched specimen. The distribution of hydrogen concentration invaded into the smooth and notched specimen was obtained by finite element analysis. The hydrogen amount is much in smooth specimen and tends to concentrate in the vicinity of surface. Hydrogen embrittlement susceptibility of notched specimen after hydrogen charging is more remarkable than that of smooth specimen.

이 연구에서는 친환경적이고, 효율적인 수소생산방식으로 알려진 고온수증기전기분해(HTSE)에 대한 열․화학적 특성 및 수소 생산 특성을 파악하고자 하였으며, 이론적 고찰과 더불어 정밀한 전산유체해석(CFD)를 통하여 획득한 결과를 제시하였다. 연구의 주요 파라메터로는 ASR(Area Specific Resistance)의 영향 및 유입가스의 온도와 압력 등이다. 상용 FEM CODE인 COMSOL Multiphysics ver. 3.3 소프트웨어를 이용하여 2차원 정상상태 전산유체해석을 실시하였으며, 다음과 같은 결론을 얻었다. 1) ASR 값이 증가함에 따라 cell 내부의 온도는 하강하였 고, 수소생산율도 낮아졌다. 2) 입구압력이 0.1MPa과 5MPa인 경우를 비교한 결과 0.1MPa일 때가 5MPa일 때 보다 최대속도를 기준으로 약 52 배 빠른 속도를 나타내며, cell의 최대온도를 기준으로 약 6.6K 가량 높은 것으로 확인되었다.

A diagnostic tool has been proposed to convert the observed surface distribution of hydrogen recombination line intensities into the radial distributions of the electron temperature and the density in HII regions. The observed line intensity is given by an integral of the volume emission coefficient along the line of sight, which comprises the Abel type integral equation for the volume emission coefficient. As the emission coefficient at a position is determined by the temperature and density of electrons at the position, the local emission coefficient resulted from the solution of the Abel equation gives the radial distribution of the temperature and the density. A test has been done on the feasibility of our diagnostic approach to probing of HII regions. From model calculations of an HII region of pure hydrogen, we have theoretically generated the observed surface brightness of hydrogen recombination line intensities and analyzed them by our diagnostic tool. The resulting temperatures and densities are then compared with the model values. For this case of uniform density, errors in the derived density are not large at all the positions. For the electron temperature, however, the largest errors appear at the central part of the HII region. The errors in the derived temperature decrease with the radial distance, and become negligible in the outer part of the model HII region.

Polymer electrolyte membrane fuel cell (PEMFC) performance degrades when hydrogen sulfide (H2S) is present in the fuel hydrogen gas; this is referred to as H2S poisoning. This paper reveals H2S poisoning on PEMFC by measuring electrical performance of single cell FC under various operating conditions. The severity of H2S poisoning depended on H2S concentration under best operating conditions(65℃ of cell temperature and 100% of anode humidification). H2S adsorption occured on the surface of catalyst layer on MEA, but not on the gas diffusion layer(GDL) by analyzing SEM/EDX data. In addition, MEA poisoning by H2S was cumulative but reversible. After poisoning for less than 150 min, performance of PEMFC was recovered up to 80% by just inert nitrogen gas purging.

We have accomplished a various reaction experiment for a purifying agent selection which is related with efficient site demobilization about soil contaminated with the total petroleum hydrocarbon(TPH) in link of contaminated soil purification enterprise of power train center in Y railway car places of business for an oxidizer comparison experiment, we have differed consistency and implantation quantity of the hydrogen peroxide (H2O2). The result showed the highest 98.8% removal ratio, when H2O2 is 35% consistency. In the same way, the result which implants at 1:1 ratio (hydrogen peroxide (H2O2) : the catalyst (FeSO4 ․7H2O)) showed a similar result, when only the hydrogen peroxide was implanted.

ZnO thin films were prepared on a glass substrate by radio frequency (RF) magnetron sputtering without intentional substrate heating and then surfaces of the ZnO films were irradiated with intense electrons in vacuum condition to investigate the effect of electron bombardment on crystallization, surface roughness, morphology and hydrogen gas sensitivity. In XRD pattern, as deposited ZnO films show a higher ZnO (002) peak intensity. However, the peak intensity for ZnO (002) is decreased with increase of electron bombarding energy. Atomic force microscope images show that surface morphology is also dependent on electron bombarding energy. The surface roughness increases due to intense electron bombardment as high as 2.7 nm. The observed optical transmittance means that the films irradiated with intense electron beams at 900 eV show lower transmittance than the others due to their rough surfaces. In addition, ZnO films irradiated by the electron beam at 900 eV show higher hydrogen gas sensitivity than the films that were electron beam irradiated at 450 eV. From XRD pattern and atomic force microscope observations, it is supposed that intense electron bombardment promotes a rough surface due to the intense bombardments and increased gas sensitivity of ZnO films for hydrogen gas. These results suggest that ZnO films irradiated with intense electron beams are promising for practical high performance hydrogen gas sensors.

The purpose of this study is to estimate concentration and emission unit of ammonia and hydrogen sulfide released from domestic chicken buildings by field investigation. Mean concentrations of ammonia and hydrogen sulfide emitted from chicken buildings were 18.25(±4.78)ppm and 807.53(±526.17)ppb for caged layer house, 14.48(±4.13)ppm and 644.82(±312.48)ppb for broiler house, and 6.16(±2.02)ppm and 284.75(±232.08)ppb for layer house with manure belt, respectively. Mean emission coefficients of ammonia and hydrogen sulfide were 0.951(±0.131) g hen^-1h^-1 and 2.956(±0.968) mg hen^-1h^-1 based on head whereas they were 0.575(±0.082) g m^-2h^-1 and 12.44(±3.536) mg m^-2h^-1 based on time. In conclusion indoor concentration and emission coefficient of ammonia and hydrogen sulfide were highest in caged layer housed, followed by broiler house and layer house with manure belt.

Traditionally Nuclear Research and Development (R&D) result has been big influence on other industries and societies and it requires large scale investments and study period. So it is essential to apply Quality Assurance (QA) for systematic R&D management

High strength sheet steels for automobile are seriously compromised by hydrogen embrittlement. This issue has been continuously studied, but the field of interest, which lies between microstructural characteristics and hydrogen behavior with hydrogen charging, has not yet been thoroughly investigated. This study was done to investigate the behavior of hydrogen according to the hydrogen volume fraction on 590MPa grade DP steels, which are developed under hydrogen charging conditions as high strength sheet steels for automobiles. The penetration depths and the mechanical properties, according to charging conditions, were investigated through the distribution of micro-hardness and the microstructural observation of the subsurface zone. It was found that the amount of hydrogen trapping in 590MPa DP steels was related to the austenite volume fraction. It was confirmed that the distribution of micro-hardnesses according to the depth of the subsurface zone under the free surface showed the relationship of the depth of the hydrogen saturation between the charging conditions.

The hydrogen energy had recognized clean and high efficiency energy source. The research field of hydrogen energy was production, storage, application and transport. The commercial storage method was using high pressure tanks but it was not safety. However metal hydride was very safety due to high chemical stability. Mg and Mg alloys are attractive as hydrogen storage materials because of their lightweight and high absorption capacity (about 7.6 wt%). Their range of applications could be further extended if their hydrogenation properties and degradation behavior could be improved. The main emphasis of this study was to find an economical manufacturing method for Mg-Ti-Ni-H systems, and to investigate their hydrogenation properties. In order to examine their hydrogenation behavior, a Sievert's type automatic pressure-compositionisotherm (PCI) apparatus was used and experiments were performed at 423, 473, 523, 573, 623 and 673 K. The results of the thermogravimetric analysis (TGA) revealed that the absorbed hydrogen contents were around 2.5wt.% for (Mg8Ti2)-10 wt.%Ni. With an increasing Ni content, the absorbed hydrogen content decreased to 1.7 wt%, whereas the dehydriding starting temperatures were lowered by some 70-100 K. The results of PCI on (Mg8Ti2)-20 wt.%Ni showed that its hydrogen capacity was around 5.5 wt% and its reversible capacity and plateau pressure were also excellent at 623 K and 673 K.

Titanium powders have been usually produced by de-hydrogenating treatment in vacuum with titanium hydride () powders prepared by milling of hydrogenated sponge titanium, . The higher stoichiometry of x in , whose maximum value is 2, is achieved, crushing behavior is easier. powder can be, therefore, easy to manufactured leading to obtain higher recovery factor of it. In addition, contamination of the powder can also minimized by the decrease of milling time. In this study, the hydrogenation behavior of sponge titanium was studied to find the maximum stoichiometry. The maximum stoichiometry in hydride formation of sponge titanium could be obtained at for 2 hrs leading to the formation of and the treating temperatures lower or higher than caused the poor stoichiometries by the low hydrogen diffusivity and un-stability of , respectively. Such experimental behavior was compared with thermodynamically calculated one. The hydrogenated sponge was fully ball-milled under -325 Mesh and the purity of pure titanium powders obtained by de-hydrogenation was about 99.6%.