http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
화학당량에 따른 우라니아의 핵분열 기체 확산 계수 측정
김희문(H. Kim),박광헌(K. Park),김봉구(B. G. Kim),주용선(Y. S. Choo),김건식(K. S. Kim),송근우(K.W. Song),홍권표(K. P. Hong),강영환(Y. H. Kang) 한국표면공학회 2002 한국표면공학회지 Vol.36 No.1
The diffusion coefficient of Xe-133 was obtained from an annealing test. The specimens were made from a UO₂ single crystal powder with natural enrichment. Weight and grain size were 300mg and 23(㎛, respectively. Oxygen potentials were obtained from an oxygen sensor. Released fractions were obtained from both results of gamma scans and quantitative analysis with MCNP code, The annealing test was performed at three temperatures at once. Diffusion coefficients of Xe-133 were calculated using slope of Booth theory in each O/M ratios. Activation energy and the pre-exponential factor of the diffusion coefficient were obtained. The activation energy of near stoichiomeric UO₂ is 310 kJ/mol. The measured values of near stoichiometric UO₂ are very close to other data available. Diffusion coefficients increase with hyper-stoichiometry, due to higher concentration of cation vacancies.
요드분위기에서 지르칼로이 피복재의 저변형율속도 의존성(I)
최용,강영환,류우석,임창생,Choi, Y.,Kang, Y.H.,Ryu, W.S.,Rim, C.S. Korean Nuclear Society 1985 Nuclear Engineering and Technology Vol.17 No.3
온도 및 연신율 변촤가 Zircaloy-4의 요드 응력부식 거동에 미치는 영향을 30$0^{\circ}C$에서 일정 하중법과 300, 350, 40$0^{\circ}C$에서 일정 연신율법으로 ($10^{-5}$sec~$10^{-6}$ sec) 3.34mg $I_2$/㎤의 요드분위기에서 연구하였다. 요드 응력부식균열에 대한 저항성은 온도가 상승하거나 변형속도가 감소하면 감소했고 파손 시간과 응력과의 관계는1/tf∝exp (0.3$\sigma$/$\sigma$uTs-31.5)로 표시할 수 있었다. 30$0^{\circ}C$에서 요드 응력 부식 균열에 대한 저항성을 불활성 분위기에서의 파손에너지에 대한 요드분위기에서의 파손 에너지의 비율로 표시할 때 변형속도가 7.6$\times$$10^{-6}$ sec 부근에서 저항성이 가장 낮았고 온도가 35$0^{\circ}C$, 40$0^{\circ}C$ 로 증가함에 따라 보다 높은 변형속도에서 최저 저항성을 나타내는 경향을 보였다. 요드 응력부식 균열의 파단면에서 준-벽계 파면(quasi-cleavage fracture)을 관찰했다. 전술한 결과에 의하면 Zircaloy-4의 요드 응력부식균열의 기구에 있어서 보호 피막파손단계 (film rupture step)가 중요한 과정으로 추정된다. The effects of temperature and strain rate on the I-SCC behaviors of Zircaloy-4 were investigated by constant load test at 30$0^{\circ}C$ and constant elongation rate test at 300, 350 and 40$0^{\circ}C$ in 3.34mg $I_2$/㎤. The results showed that I-SCC susceptibility increased as the strain rate decreased or the temperature increased. The empirical relation between the stress and the time to failure at 30$0^{\circ}C$ was given by 1/ $t_{f}$∝exp (0.3$\sigma$/$\sigma$$_{UTS}$-31.5) When the I-SCC susceptibility was expressed by the ratio of fracture energy in iodine atmosphere to that in the inert atmosphere, severe I-SCC susceptibility was found near 7.6$\times$10$^{-6}$ sec at 30$0^{\circ}C$ and the maximum point of I-SCC susceptibility tended to shift to the higher strain rate with increasing the temperature. The quasi-cleavage fracture was observed in I-SCC fracture surface. From these results, it was certain that the film repture step was involved as an important process in the I-SCC mechanism of Zircaloy-4.4.
최형식(H. S. Choi),이상준(S. J. Lee),오주환(j. h. Oh),강영환(y. h. Kang) 한국정밀공학회 2006 한국정밀공학회 학술발표대회 논문집 Vol.2006 No.5월
In this paper, design modification was performed to improve the structure of ex-developed 12 D.O.F Biped walking robot, KUBIR-1 similar with human beings. The motion of KUBIR-1 was slow and had a limited walking space. Hence I designed an improved BWR named KUBIR-2 with 12 degree of freedom. KUBIR-2 was designed to solve the following problems of KUBIR-1. First, KUBIR-2 was more simply designed in the four-bar-link mechanism, and its weight was reduced. Second, it had the built-in controller and motor driver. Third, walking velocity of KUBIR-2 was increased by improvement of speed and motion joint angle range. In addition to these, we modified the structure of the foot for more stable walking.
원추형 하단부 구조를 갖는 캡슐의 하나로와의 양립성시험
최명환(M.H. Choi),조만순(M.S. Cho),주기남(K.N Choo),박승재(S.J. Park),김봉구(B.G. Kim),강영환(Y.H. Kang) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.4
The design modification of bottom guide structures of the instrumented capsule, which is used for the irradiation test in the HANARO reactor, was required because of the trouble of the bottom guide arm's pin during irradiation. The previous structure with 3-pin arms was changed into the cone shape of one body. The specimens of the bottom end cap ring with three different sizes (φ68/70/72mm) were designed and manufactured. The out-pile tests for the capsule with previous and new three bottom guide structures were performed in the one-channel flow test facilities. In order to evaluate the compatibility with HANARO and the structural integrity of the capsule, a loading/unloading, a pressure drop, a thermal performance, a vibration, and an endurance test were conducted. From out-pile test results, the capsule with the cone shape bottom guide structures was found to be more stable than the previous structure and the optimized size of the bottom guide structure selected was 70mm in diameter. It is expected that the new bottom guide structures will be applicable to all material and special capsules which will be designed and manufactured for the irradiation tests in the future.
최명환(M.H. Choi),강영환(Y.H. Kang),조만순(M.S. Cho),김봉구(B.G. Kim),손재민(J.M. Sohn),주기남(K.N. Choo) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5
An instrumented capsule has been used for an irradiation test of various nuclear materials in the research reactor, high-flux advanced neutron application reactor, HANARO. In this study, in order to estimate the results of an irradiation test for the material capsule and to obtain the preliminary design data of the new conceptual capsule using a liquid thermal media, the thermal analysis is performed by using a 2D model for each cross section including specimens. As a result of the tests and analyses, the maximum temperature at the reactor power of 24㎿ is 255℃ for an irradiation test and 260℃ for an FE analysis in the middle stage of the capsule. Also, from the comparison of the results for the capsule with Al and LBE thermal media, it is found that the conceptual design of a LBE capsule will meet the test requirements for a high temperature irradiation of new materials in the HANARO reactor.