• Title/Summary/Keyword: He generation

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An Assessment on the Contribution of $^3$He to the Tritium Generation in the CANDU PHWR (가압중수로에서 헬륨-3이 삼중수소의 생성에 미치는 영향평가)

  • Kwak, Sung-Woo;Chung, Bum-Jin
    • Journal of Radiation Protection and Research
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    • v.22 no.2
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    • pp.119-125
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    • 1997
  • PHWR achieves high neutron economy by adopting heavy water as its moderator and coolant. On the other hand it permits much tritium generation, compared to LWR, due to the neutron capture reaction of deuterium in heavy water. Meanwhile in the reactor core, $^3He formed as the result of-decay of tritium, captures a thermal neutron and transforms to tritium again. The existing calculation models on tritium generation in PHWR neglect the contribution of $^3He$ in both moderator and coolant due to its relatively low solubility. However the neutron capture cross-section of $^3He$ is almost $1.6{\times}10^7$ times as large as that of deuterium. That means that the dissolved amount of 0.03 ppm of $^3He$ in heavy water is enough to generate the same amount of tritium as that generated by the deuterium of total heavy water in the system. This study dealt with the contribution of $^3He$ to tritium generation. As a sample case, the contribution of $^3He$ to the tritium generation in Wolsong #1 was evaluated and compared to the measured values. According to the result of this study, it is concluded that $^3He$ in coolant contributes very much to the tritium generation but that in moderator shows negligible effects due to the low solubility and $^4He$ cover gas. At the beginning of the plant operation, the contribution of $^3He$ is slightly greater than the measured value but agrees well with the measured as the operating time increases.

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MEASUREMENT OF THE D-D NEUTRON GENERATION RATE BY PROTON COUNTING

  • Kim, In-Jung;Jung, Nam-Suk;Choi, Hee-Dong
    • Nuclear Engineering and Technology
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    • v.40 no.4
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    • pp.299-304
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    • 2008
  • A detection system was set up to measure the neutron generation rate of a recently developed D-D neutron generator. The system is composed of a Si detector, He-3 detector, and electronics for pulse height analysis. The neutron generation rate was measured by counting protons using the Si detector, and the data was crosschecked by counting neutrons with the He-3 detector. The efficiencies of the Si and He-3 detectors were calibrated independently by using a standard alpha particle source $^{241}Am$ and a bare isotopic neutron source $^{252}Cf$, respectively. The effect of the cross-sectional difference between the D(d,p)T and $D(d,n)^3He$ reactions was evaluated for the case of a thick target. The neutron generation rate was theoretically corrected for the anisotropic emission of protons and neutrons in the D-D reactions. The attenuations of neutron on the path to the He-3 detector by the target assembly and vacuum flange of the neutron generator were considered by the Monte Carlo method using the MCNP 4C2 code. As a result, the neutron generation rate based on the Si detector measurement was determined with a relative uncertainty of ${\pm}5%$, and the two rates measured by both detectors corroborated within 20%.

He Generation Evaluation on Electrodeposited Ni After Neutron Exposure (중성자 조사에 따른 Ni도금피복재에서의 He발생량평가)

  • Hwang, Seong Sik;Kwon, Junhyun;Kim, Dong Jin;Kim, Sung Woo
    • Corrosion Science and Technology
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    • v.20 no.5
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    • pp.308-314
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    • 2021
  • Neutron dose level at bottom head of a reactor pressure vessel (RPV) was calculated using reactor vessel neutron transport for a Korean nuclear power plant A. At 34 EFPY with a 40-year (2042) design life after plating repair, irradiation fast neutron effect was 6.6x1015 n/cm2. As helium(He) gas can be generated by Ni only at 1/106 level of 5 × 1021 n/cm2, He generation possibility in the Ni plating layer is very little during 40 years of operation (2042, 34 EFPY). Thermal neutrons can significantly affect the generation of He from Ni metal. At 10 years after a repair, He can be generated at a level of about 0.06 appm, a level that can add general welding repair without any consideration. After 40 years of repair, 9.8 appm of He may be generated. Although this is a rather high value, it is within the range of 0.1 to 10 appm when welding repair can be applied. Clad repair by Ni electroplating technology is expected to greatly improve the operation efficiency by improving the safety and shortening the maintenance period of the nuclear power plant.

Effects of Intravenous He-Ne Laser Irradi on Meridian-Heart·Circulation CMP and Hyperlipidemia (정맥혈관내(靜脈血管內) 헬륨-네온 레이저 조사(照射)가 메리디안 심(心)·순환(循環) 대표점(代表點)과 고지혈증(高脂血症)에 미치는 영향(影響))

  • Ahn, Soo-gi;Lee, Sam-ro;Hwang, Woo-jun
    • Journal of Sasang Constitutional Medicine
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    • v.10 no.1
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    • pp.269-284
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    • 1998
  • The purpose of this study was to investigate the effect of ILIB(Intravenous Laser Irradiation of blood) on Meridian-Heart Circulation CMP and Hyperlipidemia. Circulatory symptom of 20 patients was treated with ILIB. After 10 times' treatment, changes of total cholesterol, HDL-cholesterol, triglyceride and Meridian-Heart Circulation CMP value were observed. The results were as follows : 1. In observation of Meridian-Heart Circulation CMP value, significant increase was observed in both pre-ID generation and post-ID generation. So, distinctive observation between pre-ID generation and post-ID generation became not relatively significant. 2. In observation of Meridian-Heart Circulation CMP value, significant increase was observed in both left and right. So, distinctive observation between left and right became not relatively significant. 3. In observation of Meridian-Heart CMP value, significant increase was not observed in control group, but significant increase close to normal value was observed in treatment group after treatment of Intravenous He-Ne Laser Irradiation. 4. In observation of Meridian-Circulation CMP value, significant increase was not observed in control group, but significant increase close to normal value was observed in treatment group after treatment of Intravenous He-Ne Laser Irradiation. 5. In concentration of plasma total cholesterol and plasma triglyceride, significant decrease was not observed in control group, but significant increase was observed in treatment group after treatment of Intravenous He-Ne laser Irradiation. 6. Significant concentration change of plasma HDL-cholesterol was not observed in both control group and treatment group. From above results, it was thought that Intravenous He-Ne Laser Irradiation was significant effect on heart circulatory system in human body.

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Prediction of Wind Power Generation at Southwest Coast of Korea Considering Uncertainty of HeMOSU-1 Wind Speed Data (HeMOSU-1호 관측풍속의 불확실성을 고려한 서남해안의 풍력 발전량 예측)

  • Lee, Geenam;Kim, Donghyawn;Kwon, Osoon
    • New & Renewable Energy
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    • v.10 no.2
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    • pp.19-28
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    • 2014
  • Wind power generation of 5 MW wind turbine was predicted by using wind measurement data from HeMOSU-1 which is at south west coast of Korea. Time histories of turbulent wind was generated from 10-min mean wind speed and then they were used as input to Bladed to estimated electric power. Those estimated powers are used in both polynominal regression and neural network training. They were compared with each other for daily production and yearly production. Effect of mean wind speed and turbulence intensity were quantitatively analyzed and discussed. This technique further can be used to assess lifetime power of wind turbine.

A Study on the Works and Artist Spirit of the Picture Book Writer Hong Seongchan (그림책작가 홍성찬의 작품 활동과 작가정신 고찰)

  • Joe, Hyeun-Ae
    • Journal of Korean Library and Information Science Society
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    • v.50 no.4
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    • pp.611-633
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    • 2019
  • The purpose of this study is to look into the meaning of Hong Seongchan who has become the first generation picture book writers in the history of Korean picture books by considering the works of the picture book author 'Hong Seongchan', the characteristics of pictures and the artist's spirit. The career that he took up from 1955 as an illustrator to 2012 when the final picture book was published is in line with the developmental process of Korean picture books. He consistently devoted himself to publishing illustrations from the days when his job as an illustrator was not noticed to the days when he finished his life as a picture book writer through his full-length period. As a result, he built a unique world of works, such as the reproduction of Korean images and emotions through complete historical research. His strong illustration spirit and craftsmanship during his lifetime became the basis of the birth of a professional group called a full-time picture book writer, and Hong Seongchan became the first generation picture book writers in the history of Korean picture books.

The generation of dark spatial soliton in photorefractive photovoltaic medium (광굴절 광기전력 물질에서의 어두운 공간솔리톤 발생)

  • 전진호;전남희;이원규;노영철;이재형;장준성
    • Korean Journal of Optics and Photonics
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    • v.12 no.1
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    • pp.48-54
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    • 2001
  • We investigate the generation of the dark spatial soliton and its role of wave guiding in Fe doped$LiNbO_3$ A cw Ar+ laser of 488 nm is used for the generation of the dark spatial soliton. The generation of the dark spatial soliton is observed even at the laser intensity as low as 10 mW/cm2. The self-defocusing effect is observed when the direction of the intensity variation is parallel to the optic axis, while it can't be seen when perpendicular to the axis. So, it is verified that the refractive index change is generated parallel to the optic axis. When 633 nm He-Ne laser beam is injected into the dark spatial soliton, the beam propagates just as in the diffraction free medium. So, it is verified that the dark spatial soliton can act as a waveguide.eguide.

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Soybean Peptides Induce Apoptosis in HeLa Cells by Increasing Oxidative Stress

  • Sung, Ho Joong;Jeong, Yu Jin;Kim, Jihyun;Jung, Eunsun;Jun, Jin Hyun
    • Biomedical Science Letters
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    • v.21 no.2
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    • pp.77-83
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    • 2015
  • Soy proteins have been extensively studied because of its multiple health benefits. However, the effects of soy proteins on human cervical cancer cells are still unclear. Therefore, this study investigated the effects of soy proteins on HeLa cells and human fibroblasts by using soybean peptides (SPs). SPs selectively increased the generation of reactive oxygen species and apoptosis in HeLa cells but not in fibroblasts. In addition, SPs suppressed the migration of HeLa cells. Although the molecular mechanisms underlying the effects of SPs on human cervical cancer cells need to be investigated further, our findings provide insights on the therapeutic effects of soy protein on cervical cancer.

Shawn Wong's American Knees: Deconstruction of Male-Centeredness and Its Possibility (숀 옹의 『미국인의 무릎』 : 남성 중심주의 해체와 그 가능성)

  • Kim, Min Hoe
    • English & American cultural studies
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    • v.14 no.2
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    • pp.23-48
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    • 2014
  • Considered as the first generation of the Chinese American male writers, Shawn Wong has often been tagged with the male-centered or cultural nationalistic writer for his first short novel Homebase since the 1970s. He has, however, shifted his own gender and cultural attitudes toward his male character in his second novel American Knees, published in 1995. By focusing on his second novel, this paper examines how Wong critically reconsiders the male-centeredness and cultural nationalism in a way to invalidate them in relationships among male and female characters in the formation of the Chinese American male's identity. Attempting to establish his own national and cultural identity as an American citizenship and the self-awareness of masculinity as a man, Rainsford Chan in Homebase believed that he could achieve his identity and masculinity with the chronological experiences related to his ancestors in American society. He even strictly erased the presence of female in his own identity formation. In doing so, he seemed to anchor his authorship at the discourse of the male-centeredness and cultural nationalist like other contemporary writers such as Frank Chin and Jeffrey Paul Chan who always strongly marked cultural tradition. By creating a non-conventional male character Raymond Ding with compromising and open-eared attitudes toward female characters, however, Wong dramatically changes the idea of representing the relationships between male and female characters in American Knees. In this novel, he suggests that the male character' identity can be properly formed not in the extreme reinforcement of masculinity or the ethnic-based cultural awareness but with the mutual understanding between male and female individuals regardless of ethnic and nationalistic biases. Consequently, Wong attempts to bail out of the male-centered images of the first generation of the Chinese American male writers through Raymond Ding.