• Title/Summary/Keyword: HE4

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Construction of Rb Charge Exchange Cell and Characteristic Experiment for He- Ion Production (He음이온 생성을 위한 Rb전하교환기의 제작 및 특성실험)

  • Hee-Seock LEE;Jun-Gyo BAK;Hae-iLL BAK
    • Nuclear Engineering and Technology
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    • v.23 no.4
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    • pp.420-425
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    • 1991
  • The Rb charge exchange cell is constructed as the He- ion source of the SNU 1.5- MV Tandem Van do Graaff accelerator. The characteristic experiment is carried out in order to determine the optimum operational conditions of the cell. The $He^{+}$ ion beam with the energy of 1~10 keV, extracted from the duoplasmatron ion source, is passed through the Rb vapor to become He- ions by the two step charge exchange reaction, i.e., $He^{+}\;+\;Rb\;{\rightarrow}\;He^{\circ\ast}\;+\;Rb^{+}\;and\;He^{\circ\ast}\;+\;Rb\;{\rightarrow}\;He^{-}\;+\;Rb^{+}$. From the experimental results, it is found that the maximum fractional yield of $He^{-}$ ions is produced at He+ ion energy of 7 keV. The optimum temperatures of the oven and the canal are determined to be $370\;^{\circ}C{\;}and{\;}95^{\circ}C$ respectively. Under the optimum operational condition the maximum fractional yield of $He^{-}$ ions is $2.42\pm0.02%$ This charge exchange cell is proved to be an effective system for the production of He- ions.

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Preferences for Home Economics Curriculum Models (가정과 교육과정 모형에 대한 선호도)

  • 채정현
    • Journal of Korean Home Economics Education Association
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    • v.8 no.1
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    • pp.33-49
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    • 1996
  • The objectives of this study were (1) to determine the preferences for three home economics curriculum Models(Concept-based curriculum Model, Competency-based curriculum Model, and Practical Problem-based curriculum Model) of Korean home economics(HE) teachers and HE teacher educators, (2) to determine the difference between HE teachers and HE teacher educators according to purposes of HE, focus of learning, organization of HE subject matter, focus of HE curriculum, focus of HE content, HE knowledge, main questions addressed through HE curriculum, teaching strategies, students’progress, and systems of action, and (3) to determine the relationships between preferences for three curriculum Models and personal and professional characteristics of HE teachers. Respondents in this study were 225 HE teachers and 35 HE teacher educators. The survey method was used in this descriptive study. The survey method was used in this descriptive study. The overall curriculum Model preference of each teacher respondent was determined by counting number of times a given Model among 10 identified variables. The data were analyzed by using Chi-square to compare the differences between the two groups. To determine the relationships between preferences for three curriculum Models and personal and professional characteristics of HE teachers, coefficient of contingency tables was used. Both of HE teacher group(79.4%) and HE teacher educator group(67.6%) preferred the practical problem-based curriculum Model the most. There was a difference between the two groups on preferences for the curriculum Models related to systems of action. No significant difference emerged when Chi-square was applied to determine difference between the two groups on overall preferences for three HE curriculum Model. The chi square values between preferences for three curriculum Model and level of school, type of school were statistically significant. Each contingency coefficient for level of school(middle school and high school) and form of school(private and public school) was 27, which means there is a low association between the preferences and level of school and the preferences and form of school.

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Gregor Mendel and the Seven Genes (1)

  • Tateno, Yoshio
    • Interdisciplinary Bio Central
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    • v.5 no.4
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    • pp.7.1-7.3
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    • 2013
  • This essay describes G. Mendel's life and his law of inheritance. He was born in a poor family in 1822 in a hamlet in Czechs. At that time the Habsburg Empire dominated over the East Europe in which Vienna was the capital. Vienna had thus been the center of culture and learning, and attracted many artists and scholars such as W. Mozart (1756- 1791), L. Beethoven (1770-1827), C. Doppler (1803-1853), S. Freud (1856-1939), G. Mahler (1860-1911), G. Klimt (1862-1918) and E. Schiele (1890-1918). Beethoven came to Vienna to learn from Mozart. Klimt was influence by Schilele. When Mahler consulted Freud about his mental problem, Freud said to him "Your mental condition was not normal, but the condition made you creative. So, do not worry too much about it." Like that, there were many interactions among them, and Mendel was no exception. Though Mendel was poor, he was fortunate in his education and scientific research, because he could have excellent supporters in his family and out of it. He learned mathematics and physics at Vienna University under the guidance of C. Doppler. He was not totally alone when he discovered his law of inheritance. It may not be true either that his law was neglected and rediscovered in the year of 1900. As his one and only paper indicates, he was one of the earliest interdisciplinary scientists.

Yun-Ji(尹指)'s Medical Thought in "Dunongyeonsocheonjimundap(鈍翁演小天地問答)" (조선조 성리학자 윤지(尹指)의 "둔옹연소천지문답(鈍翁演小天地問答)"에 나타난 의학사상 연구)

  • Chough, Won-Joon;Park, Wan-Sik
    • Journal of Korean Medical classics
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    • v.20 no.4
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    • pp.187-210
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    • 2007
  • Dunong(鈍翁), Yun-Ji had born by a concubine, and his dream didn't come true for the restraint of his social position, so he tried to train younger men. His writings still remain 4 volumes of "Dunongyeonsocheonjimundap" and "Dunongdongmongmundap(鈍翁童蒙問答)", which may be called its primer. "Dunongyeonsocheonjimundap" is written in question-and-answer form between Chal-Hye-Ja(察慧子) who has a meager knowledge and Sim-Gyeong-Ong(心耕翁) who search for the truth. It is progressed from the law of nature to human's cultivation of the mind so as to reconfirm the recognition of the unity between the heaven and human beings and lead the interpretation and practice of the metaphysical proposition. It is characterized by making use of metrical compositions to induce plain tone of argument. "Dunongdongmongmundap", whereas, uses archaic writings to describe natural science including astronomy to the beginners. Dunong's scholarship is characterized by these: He explained the metaphysical propositions by approaching usual things including oriental medicine practically; He comprised the Confucian concepts intensively to examine the Oriental studies closely; He groped for the outlooks on the world of taking serious view of human being or human body. And his medical thought is characterized by these: He attached importance to the theory of viscera and bowels based on yin-yang and five phase theory; He suggested the concrete yin-yang theory with a viewpoint of qi-blood theory; He considered the concept of 'six' only as mutual rooting of yin and yang and five visceras and six vowels, and denied the traditional six qi concepts; He explained the ghost theories of the metaphysics based on the yin-yang theory to analogize points of sameness between the oriental medicine and the metaphysics; He emphasized restore yang theory. Therefore, we can say that he regarded the human body as small heaven-earth and grafted the abstract propositions into the actuals so as to put the metaphysical propositions in practice.

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ORI2 is a Strong Inhibitor of Coxsackievirus B4 Replication (오리방풀로부터 분리된 ORI2의 췌장염 유발 콕사키바이러스B4 증식억제)

  • Lim, Byung-Kwan;Jo, Soyeon;Kim, Jin Hee
    • Korean Journal of Pharmacognosy
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    • v.45 no.4
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    • pp.282-287
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    • 2014
  • The ORI2 (3-[3,4-dihydroxyphenyl]acrylic acid 1-[3,4-dihydroxyphenyl]-2-methoxycarbonylethyl ester) was purified from the extract of Isodon excisus. We confirmed the antiviral effect of ORI2 in a coxsackievirus-induced pancreatitis model. Coxsackievirus B4 (CVB4) is a common cause of pancreatitis and may be reason of the type-1 diabetes. Anti-enteroviral compounds were screened by HeLa cell survival assay. Purified natural compounds were added to HeLa cells cultured 96-well plates after $10^4PFU/ml$ CVB4 pre-incubation for 30 min. ORI2 significantly improved HeLa cell survival in a dose-dependent manner. In addition, ORI2 (1 mM) treatment was dramatically decreased virus protease 2A induced eIF4G-I cleavage and viral VP1 capsid protein production. HeLa cell virus titers and viral RNA replication were significantly decreased in ORI2-treatment in a dose dependent manner (1 mM~0.001 mM). These results demonstrate that ORI2 has a strong antiviral effect. It was significantly decreased virus replication. ORI2 may be developed as a potential therapeutic agent for CVB4.

Inhibitory Effects of High Concentrations of Estrogen, Progesterone and Tamoxifen on Proliferation of HeLa in Culture (배양된 HeLa 세포에서 고농도의 에스트로겐, 프로게스테론 및 타목시펜의 세포증식 억제효과)

  • Min, Gye-Sik
    • Journal of Life Science
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    • v.21 no.12
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    • pp.1746-1751
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    • 2011
  • This study examined the effects of estrogen, progesterone and tamoxifen at different concentrations and treatment periods on proliferation of a human cervical carcinoma cell line, HeLa, in culture, based on MTT assay. Estrogen did not have an effect on the cellular proliferation in concentrations up to $1{\mu}g$/ml for treatment periods of between 2.5 and 6 days, but significantly inhibited proliferation at a higher concentration of $10{\mu}g$/ml in a progressive manner with increasing treatment periods. Also, treatment of HeLa with more than $10{\mu}g$/ml of progesterone for 2.5 days significantly inhibited proliferation and caused a concentration-dependent inhibition with 4 days of treatment. However, longer treatment with progesterone for 6 days abolished the concentration-dependent inhibitory effect on cellular proliferation observed with the 4-day treatment period. Furthermore, tamoxifen required a higher concentration ($100{\mu}g$/ml) than estrogen to bring about the inhibitory effect on the HeLa proliferation. These results suggest that high concentrations of estrogen, progesterone and tamoxifen may suppress proliferation of HeLa, and both the concentration and the treatment period may also influence their inhibitory effects on cellular proliferation.

Effect of Overshooting on Final Masses of Type Ibc Supernova Progenitors

  • Chun, Wonseok;Yoon, Sung-Chul
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.88.1-88.1
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    • 2014
  • Helium mass in the envelope is one of the most important properties in progenitors of type Ib/c supernovae (SNe Ib/c), since SN Ib/c progenitors are distinguished by the presence of He I lines. However, previous progenitor models do not reproduce the required He mass limit($M_{He}$ < $0.14M_{\odot}$) suggested by a spectroscopic analysis of SN Ib/c. In this work, we investigated the effect of overshooting on the evolution of pure helium stars, focusing on the final He mass in the envelope, $M_{He,f}$. We used the MESA code to calculate single helium star models with the initial masses of $M_{init}=5{\sim}30M_{\odot}$, Z=0.02, 0.04 and overshooting parameters of $f_{ov}=0{\sim}0.4$. The final He mass $M_{He,f}$ decreases as $f_{ov}$ increases, due to larger burning core compared to weak overshooting models. Dependence of the final mass $M_{He,f}$ on overshooting is strongest for models with $M_{init}=7{\sim}10M_{\odot}$, and this effect originates from accelerated mass loss during transition between WNE and WC/O phase. However, $M_{He,f}$ exceeds $0.27M_{\odot}$ for all models, which still doesn't meet the criteria of $M_{He}$ < $0.14M_{\odot}$. This implies that mass loss during the post helium burning phase must be enhanced dramatically compared to what the standard models predict.

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A Case of Hydrogen Cyanide Inhalation at Working -A Case Report- (작업도중 발생한 시안화 수소흡입중독으로 내원한 환자 1례)

  • Kim Yang-Weon;Eom Young-Jin
    • Journal of The Korean Society of Clinical Toxicology
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    • v.4 no.1
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    • pp.55-57
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    • 2006
  • Cyanides and Hydrogen cyanide are used in production of chemicals, electroplating, photographic development, making plastics, fumigating ships, and some mining processes. We experienced of Hydrogen cyanide inhalation injury. A 45-year-old man worked at electroplating. As soon as he mixed sodium cyanide with acid, cyanide produced hydrogen cyanide, occasionally he inhaled Hydrogen cyanide and he lost his consciousness. He was moved to near hospital and took emergency treatment and then was transferred to our hospital. On arrival he had severe dyspnea, metabolic acidosis, and tachycardia. After he was treated with supportive method he recovered his consciousness in 20 hours at emergency room.

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A Study on Jangseoksun(張錫純)'s use of Herb Remedies (장석순(張錫純)의 약물운용(藥物運用)에 관(關)한 고찰(考察))

  • Ma, Hae-Jin;Jeong, Chang-hyun
    • Journal of Korean Medical classics
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    • v.23 no.3
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    • pp.81-101
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    • 2010
  • The results of researching Jang's use of herb remedies through his book "Uihakchungjungchamseorok(醫學衷中參西錄)" are as follows. 1. Jang Seoksun's medicine is based on "Hwangjenaegyeong(黃帝內經)", "Sanghanron(傷寒論)", "Sinnongbonchogyeong(神農本草經)". And through constant study he brought to perfection his own unique medical theory. 2. He introduced Western medicine, and united it with traditional Chinese medicine. He perfected the Chinese-Western medical theory, by Chungjungchamseo(衷中參西) which means 'roots in traditional Chinese medicine, reference in Western medicine'. 3. He thought Onbyeong(溫病) was not an independent category of disease, but included it into the category of Sanghan(傷寒). So he used modified prescription of "Sanghanron(傷寒論)" to treat Onbyeong(溫病). 4. He expanded the category of remedy uses by using various compounds, such as minerals and animal compounds. He has also developed substitute remedies.