• 제목/요약/키워드: Che-Yong

검색결과 119건 처리시간 0.029초

Alkyl Hydroxy Benzoate Preservatives (Parabens) Are Estrogenic Compounds; Their Adverse Effects on Animals and Human

  • Kang, Kyung-Sun;Che, Jeong-Hwan;Park, Jin-Sung;Lee, Yong-Soon
    • Toxicological Research
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    • 제17권
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    • pp.309-312
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    • 2001
  • It has recently been suggested that the release of "endocrine disrupters (EDs)" into the environment has resulted in adverse health effects on wild life populations and humans (Golden et al., 1998; Tyler et al., 1998; Kang et al., 2000). Human sperm counts have declined significantly throughout the world during the past fifty years, and which is a significant public health concern (Carlsen et al., 1992; Carlsen et al.. 1995). In addition, the EDs persisting in the environment are known to disrupt the normal endocrine systems of wildlife (Colborn, 1995; Crewet al., 1995; Folmer et at, 1996; Sumpter, 1995; Tyler, 1998). Some estrogenic chemicals bind to estrogen receptors (Bolger et al.. 1998), interfere with the binding of physiological ligands to steroid hormone-binding proteins (Danjo, 1997; Milligan et al., 1998). and show immunotoxicity (Sakae et al., 1998). (omitted) (omitted)

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Application of Denaturing Gradient Gel Electrophoresis to Estimate the Diversity of Commensal Thermophiles

  • Bae, Jin-Woo;Kim, Joong-Jae;Jeon, Che-Ok;Kim, Kwang;Song, Jae-Jun;Lee, Seung-Goo;Poo, Har-Young;Jung, Chang-Min;Park, Yong-Ha;Sung, Moon-Hee
    • Journal of Microbiology and Biotechnology
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    • 제13권6호
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    • pp.1008-1012
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    • 2003
  • Symbiobacterium toebii has been reported as a thermophile exhibiting a commensal interaction with Geobacillus toebii. The distribution of the commensal thermophiles in various soils was investigated using a denaturing gradient gel electrophoresis (DGGE). Based on the DGGE analysis, the enrichment condition for the growth of Symbiobacterium sp. was found to also enrich populations of several other microbial spp. as well as Symbiobacterium sp. In the enrichment experiment, several different 16S rDNA sequences of commensal thermophiles were detected in all of the soil samples tested, indicating that commensal thermophiles are widely distributed in various soils.

솔잎으로부터 항산화 성분인 4-hydroxy-5-methyl-3[2H]-furanone의 분리 (Isolation of 4-hydroxy-5-methyl-3[2H]-furanone from Pine Needles as an Antioxidative Principle)

  • 부용출;전체옥;오지연
    • Applied Biological Chemistry
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    • 제37권4호
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    • pp.310-314
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    • 1994
  • 솔잎으로부터 프리 라디칼 소거 작용이 있는 물질을 분리하고, 여러 기기 분석 결과에 근거하여 4-hydroxy-5-methyl-3[2H]-furanone으로 동정하였다. 아울러 xylose와 glycine의 Maillard 반응을 통하여 이 물질을 합성하였다. 이 물질은 1,1-diphenyl-2-picrylhydrazyl(DPPH) 프리 라디칼에 대해 소거 작용을 보였으며(100 M의 DPPH의 50%를 환원 시키는데 필요한 농도, 즉 $SC_{50}=26\;{\mu}M$) 이는 구조적으로 유사한 공지의 항산화 물질인 $4-hydroxy-2,5-dimethyl-3[2H]-furanone(SC_{50}=53\;{\mu}M)$$3-hydroxy-2-methyl-{\gamma}-pyrone(SC_{50}=4.0\;mM)$에 비해 강력한 것이다. 4-Hydroxy-5-methyl-3[2H]-furanone은 3,4-dihydroxyphenylalanine과 linolenic acid의 자동 산화에 대해서 억제 작용을 나타내었다.

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실내모형시험을 통한 점성토 지반의 토피고에 따른 지표침하 특성연구 (A study on surface settlement characteristics according to the cohesive soil depth through laboratory model tests)

  • 김영준;임채근;강세구;이용주
    • 한국터널지하공간학회 논문집
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    • 제16권6호
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    • pp.507-520
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    • 2014
  • 본 연구는 점성토 지반에서 터널 굴착장비를 이용하여 터널을 굴착할 때 토피고 변화에 따라 발생하는 지표변위 특성을 고찰하였다. 이를 위하여 현장조건과 유사한 시료를 이용하여 실내축소모형시험을 수행하였다. 토피고에 따라 1.5D, 2.0D, 2.5D, 3.0D의 총 4개의 Case 에 대하여 모형시험을 수행하였다. 이러한 모형시험을 통하여 터널굴착 시 발생하는 지표변위를 측정하여 3차원적 영향분포를 정량적으로 분석하였으며, 더불어 변위양상도 규명하였다.

《동의수세보원(東醫壽世保元)》과 《명선록(明善錄)》에 나타난 주요(主要) 어구(語句)에 관(關)한 비교(比較) 연구(硏究) (A Study on Comparison of Key Words from between Dongyisusebowon and Myungsunrok)

  • 유준상;김달래
    • 사상체질의학회지
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    • 제9권1호
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    • pp.273-297
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    • 1997
  • The objective of this article is to carry on the comparative study of the two books, Dongyisusebowon and Myungsunrok. Je-Ma Lee showed, in fact, the intellectual achievement in his book, Dongyisusebowon. And Lee showed more close relationships with Suk-Ji Han's idea. The common ideas from this comparative study of both scholars are as follows. 1. Lee understands the real character of human being according to Chu-Ztu(朱子)'s doctrine, with the supplement of Han's. 2. Lee explains the Sung-Jung(性情) in Cosmology and the theory of Human Nature, but he concentrates upon the Sung-Jung in the theory of Human Nature, especially in constitutional medicine. 3. Lee states the Tai-Geuk(太極) in the meaning of heart from the medical viewpoint, he agrees with the Han's idea. 4. I try to comprehend Myungsunrok in the Wang-Yang-Ming(王陽明)'s concept. 5. Han explains that Sung-Jung-I-Ki(性情理氣) is one concept with two aspects, Che-Yong(體用). In addition, Lee has formed his 'Chun-In-Sung-Myung(天人性命)' thought in harmonization with Han's idea and Chu-Tzu's idea.

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Investigating creep behavior of Ni-Cr-W alloy pressurized tube at 950 ℃ by using in-situ creep testing system

  • Zhong, Yang;Lan, Kuan-Che;Lee, Hoon;Zhou, Bomou;Wang, Yong;Tsang, D.K.L.;Stubbins, James F.
    • Nuclear Engineering and Technology
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    • 제52권7호
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    • pp.1481-1485
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    • 2020
  • The creep behavior of Ni-Cr-W alloy at 950 ℃ has been investigated by a novel creep testing system which is capable of in-situ measurement of strain. Tubular specimens were pressurized with argon gas for effective stresses up to 32 MPa. Experimental results show that the thermal fatigue reduces the creep life of the tubular specimens and with the introduction of thermal cycling fatigue the primary stage disappears and the creep rate higher than the pure thermal creep (without thermal fatigue). Also the creep behavior of Ni-Cr-W alloy doesn't consist in the secondary stage. A new creep equation has been derived and implemented into finite element method. The results from the finite element analyses are in good agreement with the creep experiment.

미세 유체통로를 이용한 대면적 평판 구조의 부양에 관한 연구 (Study on the Micro Channel Assisted Release Process)

  • 김재흥;이준영;김용권
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 C
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    • pp.1924-1926
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    • 2001
  • A novel wet release process ($\mu$ CARP - Micro Channel Assisted Release Process) for releasing an extreme large-area plate structure without etching hole is proposed and experimented. Etching holes in conventional process reduce a effective area and degrade an optical characteristics by a diffraction. In addition, as the area of a released structure increases, the stietion becomes more serious. The proposed process resolves these problems by the introduction of a micro fluidic channel beneath the structure which will be released. In this paper, a 5 mm${\times}$5mm-single crystal silicon plate structure was released by the proposed $\mu$CARP without etch holes on the structure. The variation in etching time with respect to the of the introduced micro channel is also examined. This process is expected to be beneficial for the actuator of a nano-scale data storage and the scanning mirror.

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최적 T-Bar Offset(Vertical Stiffener Misalignment) 허용오차 정립 (The Optimum Offset Range on the Top of T-Bar Stiffener and Bracket)

  • 이경석;유창화;손상용;제정신
    • 대한조선학회 특별논문집
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    • 대한조선학회 2008년도 특별논문집
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    • pp.1-9
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    • 2008
  • This report contains the results of structural analysis for the verification of the optimum offset range on the top of T-Bar with stiffener and BKT using at DSME Offset range as $6.0{\sim}10.0mm$ based on the 3-D FE analysis and experimental results of angie type stiffener as described in Annex 1 has been used as yard standard over ten (10) years under all Classification approval. Recently, Owner and Class have requested the confirmation for the misalignment based on the Yard's Standard so that a couple of locations for LNGC and LPGC has been investigated the structural strength by FE method using the offset ranges from 0.0 to 18.0 mm.

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XY-Stage에 의해 정적인 변위를 갖는 미세 프레넬 렌즈(Micro-Fresnel Lens)의 설계 및 제작 (Design and Fabrication of Movable Micro-Fersnel Lens on XY-stage)

  • 김재흥;안시홍;임형택;김용권
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 G
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    • pp.2515-2517
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    • 1998
  • The micro fresnel lens(MFL) was modeled and fabricated on a XY-stage electrostatically driven by comb actuator. The modeled MFL was approximated as a step shape with 4-phase and 4-zone plate. The focal length and diameter of the MFL is 20mm and 912${\mu}m$, respectively. The XY-stage suspending the MFL is designed to generate a large static displacement up to about 20${\mu}m$. On SOI substrates, we first fabricated MFL using the RIE(reactive Ion etching) technology and then patterned and etched bulk silicon to make XY-stage. After the fabrication of all structures on top side of the SOI substrates. $Si_3N_4$ was deposited for passivation of all structures using PECVD(plasma enhanced chemical vapor deposition). All the MFL systems width comb drive actuator were released by KOH etching from the bottom side of the SOI wafer using double-sided alignment technique. In fabrication of MFL, a dry etching conditions is established in order to improve surface roughness and to control the etched depth.

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