Effect of Hydride Reorientation on Delayed Hydride Cracking In Zr-2.5Nb Tubes

Yun Yeo Bum,Kim Young Suk,Im Kyung Soo,Cheong Yong Moo,Kim Sung Soo Korean Nuclear Society 2003 Nuclear Engineering and Technology Vol.35 No.6

The objective of this study is to investigate the reorientation of hydrides with applied stress intensity factor, the peak temperature and the time when to apply the stress intensity factor in a Zr-2.5Nb pressure tube during its thermal cycle treatment. Cantilever beam (CB) specimens with a notch of 0.5 mm in depth made from the Zr-2.5Nb tube were subjected to electrolytic hydrogen charging to contain 60 ppm H and then to a thermal cycle involving heating to the peak temperature of either 310 or $380^{\circ}C$, holding there for 50 h and then cooling to the test temperature of $250^{\circ}C$. The stress intensity factor of either 6.13 or $18.4\;MPa\sqrt{m}$ was applied at the beginning of the thermal cycle, at the end of the hold at the peak temperatures and after cooling to the test temperature, respectively. The reorientation of hydrides in the Zr-2.5Nb tube was enhanced with the increased peak temperature and applied stress intensity factor. Furthermore, when the CB specimens were subjected to $18.4\;MPa\sqrt{m}$ from the beginning of the thermal cycle, the reoriented hydrides occurred almost all over the Zr-2.5Nb tube, surprisingly suppressing the growth of a DHC crack. In contrast, when the CB specimens were subjected to the stress intensity factor at the test temperature, little reorientation of hydrides was observed except the notch region, leading the Zr-2.5Nb to grow a large DHC crack. Based on the correlation between the reorientation of hydrides and the DHC crack growth, a governing factor for DHC is discussed along with the feasibility of the Kim's DHC model.

인공타액에서 염소 및 황이온이 치과용 아말감의 전기화학적 부식에 주는 영향

김철위,김명국,백기석,임범순 대한치과기재학회 1996 대한치과재료학회지 Vol.23 No.2

The amalgam alloys contained the Ag, Sn, and Cu. Alloys containing Ag and Cu suffer sulfide tarnish and chloride corrosion. The purpose of this study was to evaluate the effect of Cl and S ions in artificial saliva on electrochemical corrosion dental amalgam and clarify the effect of sulfides on chlorides corrosion of dental amalgam. Eight types of dental amalgams were selected; four conventional dental amalgam alloys (BSA, CVX, HIA, and STF) and four high copper alloys (A21, LGA, LUX, and TYT). Fusayama's modified artificial saliva was used as standard electrolyte (concentrations of Cl and S ion were 12.22 mM/ℓ, 0.1mM/ℓ respectively). The concentration of Cl ions was modified to 1.22mM/ℓ, 12.22mM/ℓ, 24.44mM/ℓ, and 61.10mM/ℓ. As the Cl ions fixed at 12.22 mM/ℓ and 24.44mM/ℓ, the concentration of S ions in the artificial saliva was also modified to 0.1mM/ℓ, 0.5mM/ℓ, 1.0 mM/ℓ, and 5.0mM/ℓ. Specimens were tested by potentiostatic anodic polarization technique with scanning rate of 1 mV/sec. from -1200 mV to +800 mV at 37±2℃ From the experiment, the following results were obtained: 1. In the standard electrolyte, the corrosion resistance of the high-copper amalgams was higher than that of the conventional amalgams since the range of passivity for the high-copper amalgams was 200 mV wider than that of the conventional amalgams. 2. As the amount of chloride in the artificial saliva increased, the corrosion resistance of the conventional amalgams was decreased but the passivity of the high-copper amalgams was not changed. 3. When the concentraion of Cl was kept at 12.22 mM/ℓ, the increase of S had a little on the corrosion potential but caused increase of current density of the conventional amalgams. The corrosion resistance of the high-copper amalgams was decreased with similar trend to the conventional amalgams. 4. When the concentraion of Cl was kept at 61.10 mM/ℓ, the increase of S had a little on the corrosion behavior of the conventional amalgams. In case of high-copper amalgams, however, the corrosion resistance was decreased.

조기유자망 어구의 개량 및 생력화 조업시스템 개발 : 3. 생력형 5단 양망기의 해상 성능 시험

김석종,구명성,강경범,서대범,정용진 제주대학교 해양과환경연구소 2005 해양과환경연구소 연구논문집 Vol.29 No.2

유방암에서 PCR을 이용한 p53 유전자의 Codon 175에서의 점돌연변이에 관한 연구

김영철,김종석,김선한,목영재,최상용,문홍영,구범환 고려대학교 의과대학 1993 고려대 의대 잡지 Vol.30 No.2

The p53 gene, which is located in the short arm of chromosome 17, has been a constant source of fascination since its discovery at 1979. Allelic deletion coupled with mutation of the remaining allele is a theoretical hallmark of functional inactivation of tumor suppressor gene, and mutation and/or deletion of p53 gene is to be the most frequently observed genetic changes in breast cancer related to a single gene. In the present report, we have attempted to determine a point mutation at codon 175 which is known as one of four hot spots within highly conserved regions of the p53 gene where almost all of the reported mutations cluster A 304-bp fragment of exon 5 of p53 gene in fresh tissue of breast carcinoma was amplified by polymerase chain reaction (PCR), digested with Hha I restriction endonuclease, and electrophoresed. A point mutation was studied by observation of polymorphism with ethidium bromide staining under ultraviolet transillumination. The result revealed all of 14 carcinomas had wild-type p53 gene.

공동주택의 에너지 절약 및 공기환경개선을 위한 열교환기의 성능평가

김범석,정용호,박병윤,손장열 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1

This study was aimed to suggest the appropriate residential heat and moisture recovery ventilation systems(HRVs) in order to maintain an acceptable indoor air quality for the climatic conditions of Korea. This study was developed from experimental data on HRV Performance specifications and HVAC system. Results show that total heat exchangers of rotary type is applied on HVAC system that is possible to conserve energy and improve indoor air quality.

유아 운동 프로그램 참가에 대한 부모의 발달기대 분석

김석일,신범철,육조영 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.6

The purpose of this study was to examine the mothers' developmental expectancy toward their child taking part in the motor programs. The subjects were 185 mothers having children at the age of three to six who were participating in the motor programs in the sports clubs. The subjects answered a questionnaire consisting of 35 items about the developmental expectancy. The main results can be summarized as follows: 1) Factor analysis with normal varimax rotation to the questionnaire revealed the developmental expectancy consists of seven factors;general development, competence/ mastery, courtesy, autonomy, cooperation, social skills, health/ fitness. 2) The mothers who have a lower age child scored significantly high on the fifth subscale(cooperation), while there was no differences in the other subscales. And the sports experiences of mothers only related to cooperation.

기체 방사성 물질 제거를 위한 첨착 활성탄 필터 시스템 성능에 관한 연구

김대욱,손현철,이명석,이석범,박길문 朝鮮大學校 機械技術硏究所 1999 機械技術硏究 Vol.2 No.1

This paper presents an application of impregnated activated carbon and impregnated activated carbon filters. They are used for the removal of gaseous radioactive materials at radioactive material handling facilities such as nuclear power plants and research facilities. High adsorption efficiencies as well as stability are required for them to remove hazardous radioactive gases such as activated free iodine released during normal operation or accident condition. This research was initiated to enhance the independence of nuclear industry and raise the level of nuclear technology to that of the leading nuclear nations. By attaining the capability of design and development of HVAC system, national technological competitiveness can be achieved. Also, the ground for technology export will be hardened. Therefore, it is well timed to initiate the project to develope those filter systems domestically utilizing all the relevant technologies available.

남자 고등학교 세팍타크로 경기의 공격기술에 관한 분석 연구

김영호,고문석,제임스전,이영익,차정훈,현종건,김범수,임종만,이석인 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.6

This research aims at analysis of attack technique in sepaktakraw games. For this purpose, 3 high school coaches observed and recorded each game Five times in videos of high school male players' thirty games in 2003. The conclusion from the analysis of the recorded data are as follows. 1. Scissors spike was the most popular (favorite) attack technique. Rolling spike, tapping spike and heading spike was popular in order. 2. Heading spike showed the highest success rate (73.5%) in attack technique. And tapping spike (69.5%), scissors spike (57.8%) and rolling spike (67.11) showed a lower success rate in order. In failure rate, heading spike (5.5%), tapping spike (36.5%), scissors spike (32.2%) and rolling spike (32.9%) had a higher percentage in order. 3. When receive was stable, the success rate in attach technique was 47.1%, the failure rate was 20.1%. On the other hand, when receive was unstable, the success rate in attach technique was 16.5%, the failure rate was 14.3%.

정상 성인에서 Amitriptyline이 REM 수면에 미치는 영향

김태범,왕성근,신석철 대한생물치료정신의학회 1995 생물치료정신의학 Vol.1 No.2

To investigate the effects of amitriptyline on REM sleep in normal adults, author applied polysomnography of sleep structure to the volunteer before and after administration of amitriptyline 25㎎. The subjects were 8 healthy young adults, aged from 20 to 24 years old. The results were summarized as follows. 1. Compaired with the baseline, the decrease of the absolute value of REM sleep, the decrease of total REM sleep period and duration, the increase of REM sleep interval occured in amitriptyline administration night. 2. Compaired with the baseline, the increase of the absolute value and the relative of REM sleep, the increase of total REM sleep duration, the decrease of REM sleep latency occured in the first recovery night. 3. Compaired with the baseline, the increase of the relative value of REM sleep, the increase of REM sleep efficiency occured in the second recovery night. 4. In amitriptyline administration night, REM sleep supression effect of amitriptyline occured and in the first and in the first and the second recovery night, rebound phenomenon of REM sleep occured. 5. REM sleep supression effect of amitriptyline occured in totally each REM period time rather in specific sequential REM period, but rebound phenomenon of REM sleep markedly occured in the first REM period in first recovery night.

스포츠센터 회원의 생활양식, 참여종목과 참여 촉진 요인의 관계

김경호,주석범,박순문 한국스포츠리서치 2003 한국 스포츠 리서치 Vol.14 No.6

This study is to investigate the relations with the factors like life style, participation event, and participation promotion of the members at the sports center. For investigating that, as an object for research, this study is to select the adults above 20 years old who make use of the sports center in Ilsan area in 2003 as a population. Then it is to write the sampling frame work by using the stratified cluster random sampling. After that, it is to utilize the 360 persons except for the 40 sheets of questionnaire with double entry and insincerity and without the reliability in the real analysis after the distribution of the questionnaire. As survey instruments, it is to utilize the questionnaire that the Plumer(1974) developed and that Sim Jae Seung(1998) reconstructed in order to measure the life style. As for the factor of participation promotion, this study is to utilize the desire of leisure that Kim Young Ho(1995) adapted and developed the physical desire and efficiency variable in the development model for Korean-styled leisure diagnosis instruments, and utilize the reconstructed items as Kim Hong Sik(2002)'s factor of participation promotion that used after the Ryu Byeong Ryeol(1997) adapted the scale of recognized leisure capacity and the physical activity attitudes that produced by British Columbia Ministry of Health(1991). For the data analysis, the statistical analysis was executed as one-way analysis of variance, ANOVA, multiple regression analysis and ANCOVA. The conclusions from the data analysis according to the methods and procedures like above are as follows. First, there arose differences partly in the factors like the life style, participation event, and participation promotion according to the demographical characteristics. Second, as for the life style of the members at the sports center, it made affect on the factor of participation promotion partly. Third, there arose differences in the factor of participation promotion partly according to the participation event of the members at the sports center.