http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
FUSION MATERIALS AND FUSION ENGINEERING R&D IN JAPAN
KOHYAMA A.,KONISHI S.,KIMURA A. Korean Nuclear Society 2005 Nuclear Engineering and Technology Vol.37 No.5
Japanese activities on fusion structural materials R&D have been well organized under the coordination of university programs and JAERI/NIMS programs more than two decades. Where, two categories of structural materials have been studied, those are; reduced activation martensitic/ferritic steels (RAFs) as reference material and vanadium alloys and SiC/SiC composite materials as advanced materials. The R&D histories of these candidate materials and the present status in Japan are reviewed with the emphasis on materials behavior under radiation damage. The importance of IFMIF and technology development for blanket R&D including ITER-TBRG activity is emphasized and the current status of those activities in Japan is also presented.
FUSION MATERIALS AND FUSION ENGINEERING R & D IN JAPAN
A. KOHYAMA,S. KONISHI,A. KIMURA 한국원자력학회 2005 Nuclear Engineering and Technology Vol.37 No.5
Japanese activities on fusion structural materials R & D have been well organized under the coordination of university programs and JAERI/NIMS programs more than two decades. Where, two categories of structural materials have been studied, those are; reduced activation martensitic/ferritic steels (RAFs) as reference material and vanadium alloys and SiC/SiC composite materials as advanced materials. The R & D histories of these candidate materials and the present status in Japan are reviewed with the emphasis on materials behavior under radiation damage. The importance of IFMIF and technology development for blanket R & D including ITER-TBRG activity is emphasized and the current status of those activities in Japan is also presented.
Lifestyle Habits Associated with Poor Defecation Habit among Pupils in Japan
Jun Kohyama 대한소아소화기영양학회 2020 Pediatric gastroenterology, hepatology & nutrition Vol.23 No.6
Purpose: Not enough attention has been paid to defecation habits in Japan. This study aimed to emphasize the importance of defecation habits on health and function in Japanese pupils. Methods: Using multiple regression analysis, 2,722 questionnaires obtained from pupils in grades 5 to 12 were analyzed to determine lifestyle habits associated with defecation frequency. Results: Significant regression formulae for defecation scores were obtained for all school types: elementary school (ES) (adjusted R2=0.08, p<0.001), junior high school (JHS) (0.09, p<0.001), and senior high school (SHS) (0.15, p<0.001). The following factors were associated with poorer defecation scores, according to school type: female gender (all 3 school types), breakfast skipping (elementary and JHSs), lower physical activity (JHSs and SHSs), and longer school-day screen time (elementary and SHSs). In addition, poorer selfreported academic performance scores in ES, less standardized body mass index (BMI) in JHS, and shorter non-school- day screen time scores in SHS, were associated with poorer defecation scores. Conclusion: Poor defecation frequency showed significant associations with various lifestyle habits, such as breakfast skipping, physical activity, and screen time, among pupils. Academic performance and standardized BMI were also associated with defecation frequency. More attention should be paid to defecation frequency to sustain health and function in pupils.
핵융합로용 저 방사화 페라이트강(JLF-1)의 피로균열진전 거동
윤한기(H.K. Yoon),이상필(S.P. Lee),공유식(Y.S. Kong),김사웅(S.W. Kim),박원조(W.J. Park),A.Kohyama(A. Kohyama) 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.5
The objective of this study is to investigate fatigue life and fatigue crack propagation behavior in the Reduced Activation Ferritic Steel (RAFs) JLF-I. The experiment of fatigue life for JLF-I steel have been carried out for the stress ratio R=0 at room temperature. The fatigue crack propagation behavior of the JLF-I steel was investigated by the constant-amplitude loading test for the stress ratios R=0.1, 0.3 and 0.5 respectively. The effects of stress ratios and specimen size on the fatigue crack growth behaviors for JLF-I steel were discussed within the Paris law. At room temperature, the fatigue limits of longitudinal and transverse direction to the rolling direction were 470 MPa and 490 MPa at 1X 10_7<br/> cycles. respectively. The base material of JLF-I steel showed the isotropic behavior in fatigue properties of the rolling direction and the test temperature. The fatigue crack propagation rate of a half size specimen was similar to that of a full size specimen at the stress ratios of 0.1, 0.3 and 0.5 respectively. The fatigue crack propagation behavior of this material was evaluated by using a half size specimen.
핵융합로 블랭킷용 저방사화 철강재료 TIG 용접부의 강도특성
윤한기,이상필,김동현,A. Kohyama 대한용접접합학회 2003 대한용접·접합학회지 Vol.21 No.1
JLF-1 steel (Fe-9Cr-2W-V-Ta), reduced activation ferritic steel, is one of the promising candidate materials for fusion reactor applications. Tensile properties of JLF-1 base metal and its TIG weldments has been investigated at the room temperature, $400^{\circ}C$ and $600^{\circ}C$. The tensile strength of base metal (JLF-1) showed the level between those of weld metal and the Heat Affected Zone (HAZ). When the test temperature was increased from room temperature to high temperature ($400^{\circ}C$ and $600^{\circ}C$), both strength and ductility decreased or base metal, weld metal and the HAZ. The longitudinal specimens of base metal represented similar strength and ductility at room temperature and high temperature, compared to those of transverse specimens. Little anisotropy for the rolling direction was observed in the base metal of JLF-1 steel.