• Title/Summary/Keyword: 황의만

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Surface Segregation of Sulfur in Ti and ti-Aluminide Alloys (티타늄과 티타늄 알루니마이드 합금에서 황의 표면석출)

  • 이원식;이재희
    • Journal of the Korean Vacuum Society
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    • v.5 no.1
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    • pp.39-47
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    • 1996
  • The segregation of S in electrotransport-purified polycrystaline $\alpha$-Ti and Ti-aluminide alloys has been studied by Auger electron spectroscopy(AES), Ion scattering spectroscopy(ISS) and Secondary ion mass spectrometry(SIMS) in the temperature range extending from 20 to $1000^{\circ}C$. The chemisorbed oxygen and carbon on Ti were observed to disappear at T>$400^{\circ}C$ after which the S signal increased to levels approaching 0.5 monolayer. At lower temperatures the presence of the surface oxygen and carbon appeared to inhibit the segregation, presumably because there were no available surfaces sites for the S emerging from the bulk. The activation energy for the S segregation in pure polycrystaline Ti was determined to be 16.7 kcal/mol, which, when compared to S segretation from single-crystal Ti, is quite small and suggests grain boundary or defect diffusion segregation kinetics. In the Ti-aluminide alloys, the presence of Al appeared to enhance the retention of surface oxygen which, in turn, substantially reduced the S segretation. The $\gamma$ alloy, with its high Al content, exhibited the greatest retention of surface oxygen and the smallest quantity of the S segregation(T$\simeq1000^{\circ}C$).

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Transcription level of the ars-1 promoter of Neurospora crassa (Neurospora crassa ars-1 프로모터의 발현율 조사)

  • 이병욱;구상호
    • Journal of Life Science
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    • v.13 no.2
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    • pp.191-196
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    • 2003
  • The ars gene of the Neurospora crassa encodes arylsulfatase and is expressed under sulfur limitation. An ars-1 promoter(Pars) translationally-fused to a lacZ gene was transformed into the N. crassa RLM 35-35, a his-3 inl strain and integrated into the his-S locus by a single crossover homologous recombination. $\beta$-galactosidase specific activity was measured from mycelia grown in sulfur-limited Vogel's medium. Enzyme activity reached its maximum at 14 hour after the shift to derepressing condition. When activity from homokaryon generated by microconidiation was measured, it was 17% a higher than that from heterokaryon.

Beneficiation of Low Grade Anthracites (저품위 무연탄의 처리에 관한 연구)

  • 이재장;전호석;최우진
    • Resources Recycling
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    • v.5 no.2
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    • pp.45-51
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    • 1996
  • Domestic coal contains approximnlely 03 to 7 percentage of sulfur. When the suliur in coal is burned, exhaust gas , nay be thc causc of air pollution problcms as well as acid rain. Thc government dccideil lo strengthen the environmcnlal protection policy a1 the 270 ppm of SO, for the coal-Ered plants and to stari in Ian. 1, 1999. This study was carried out lo rcmove the stlfur and mineral mancrs in the samplw using wet msg~xiic separatol ant1 oil agglomeration apparatus. The rcsults for the wet magnetic separalion showed that the total sulfur removal from Kangnung coal sample was 60.8% with 82.6% combustible recovery. For the results of oil agglomeration testa, combustible recavety, ash nod sulfur rcmovcl horn Maro coal sample were 98.0, 70.9 and 95.7 percent, respectively.

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David Henry Hwang's M. Butterfly: Postmodern Other, (Post-)Imperialist Melancholy and Western Masculinity in Crisis (포스트모던 제국의 우울증-데이빗 헨리 황의 『엠. 버터플라이』)

  • Park, Mi Sun
    • Journal of English Language & Literature
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    • v.54 no.4
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    • pp.579-597
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    • 2008
  • This article discusses David Henry Hwang's M. Butterfly as a suggestive text for examining Western masculinity in crisis in the post-imperialist age, in which territorial imperialism is no longer valid. Previous scholarship on M. Butterfly has centered around the interlocking dynamics of imperialism, racism and sexism. Such critical attentions focus on how Hwang deconstructs racialized significations of the East and the West. In these discussions, the issue of gender is often addressed merely as a trope to represent the power relations between the East and the West. As such, gender as well as sexuality is highlighted as the very source of subversion of the power relations. My discussion departs from a critique of the gendered trope of the East and the West, highlighting a postmodern agent, the allegedly feminized character Song Lining: a Chinese actor who passes for a woman for political purposes in postcolonial China. Remaining an "inappropriate/d other" in the gendered imperialist discourse, Song becomes an emergent subject, who is capable of playing gender ambiguity for reclaiming a devalued identity, that of homosexual Asian man. Discussing how the central character Rene Gallimard's masculine identity is constructed in a cross-cultural space and how it evolves, I also argue that Gallimard's melancholic death signifies a historical unsustainability of imperialist masculinity in the postmodern/postcolonial age since World War II.

The Energy Flow and Mineral Cycles in a Zoysia japonica and a Miscanthus sinensis Ecosystem on Mt. Kwanak 8. The Cycles of Sulphur (관악산의 잔디와 억새 생태계에 있어서 에너지 흐름과 무기물의 순환 8.황의 순환)

  • 강경미;장남기
    • Asian Journal of Turfgrass Science
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    • v.11 no.4
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    • pp.281-288
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    • 1997
  • This study was performed to find out the mineral cycles of sulphur in dynamic grassland ecosystems in a steady state condition at the northwest side on Mt. Kwanak. The experimental results may be summarized on the communities of a Zoysia japonica and a Miscanthus sinensis as follows. As compared with some properties of the surface soils among two semi-natural grasslands, sulphur war greater quantity in a Miscanthus sinensis than in a Zoysia japonica on Mt. Kwanak . For the case of steady production and release, the raion of annual mineral production to the amount accumulated on the top of mineral soil in a steady state provides the estimates of release constant k. The release constants on sulphur of the litter were 0.54 in a Zoysia japonica and 0.36 in a Miscanthus sinensis grassland. The half times of S required for the release or accumulation of the litter on the grassland were 1.28 years in a Zoysia japonica and 1.93 years in a Miscauthus sinensis The amounts of annual cycles for sulphur in the grassland ecosystem under the steady-state conditions were 20.65g /$m^2$ in a Zoysia japonica and 26.28g /$m^2$ in a Miacanthus sinensis grassland. Key words: Zoysia japonica Miscanthus sinensis Mt. Kwanak, Sulphur, Mineral cycles.

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Spectroscopic Evaluation on the Chemical Damage of Hair by Hydrogen Peroxide (과산화수소에 의한 모발의 화학적 손상에 관한 분광학적 평가)

  • Ha, Byung-Jo
    • Applied Chemistry for Engineering
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    • v.22 no.5
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    • pp.579-581
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    • 2011
  • Spectroscopic evaluation of hair chemical damage was performed by SEM/EDS, CLSM, and FT-IR spectroscopy. In SEM/EDS, hydrogen peroxide treated hair showed the loose packing of surface scales, lower ratio of sulfur element and higher ratio of oxygen atom. In the optical single section by using CLSM, high fluorescent intensity appeared in untreated hair. However, in case of treated hair, low fluorescent intensity appeared. This results the aromatic amino acids which can be autofluorescent were more abundant than bleached hair. FT-IR spectra showed that cysteic acid band intensity was increased by performing the bleaching treatments. These results indicate that the oxidative damage cleaves the S-S bond and results in the lower working force of hair fiber.

Effect of Light Quality on the Growth of Panax ginseng in a Phytotron With Natural Light (자연광기상실에서 인삼생육에 대한 광질의 영향)

  • Park, Hoon;Lee, Mee-Kyoung;Ahn, Sang-Deuk
    • Journal of Ginseng Research
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    • v.13 no.2
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    • pp.165-168
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    • 1989
  • Ginseng plants in the 2nd year were grown under the shade (90-95%) of colored cellophane films at $15^{\circ}C$ in a natural light phytotron. Relative root grown (final/initial) was in decreasing order of blue, green, white, yellow and red. The growth of aerial part, especially stem length was poorest in blue light with relative root growth negatively correlated with stem length. In this relation each color showed specific domain. Stem length showed positive linear correlation with leaf area per plant in each and among light though it was not significant in red light. The content and ratio of chlorophyll a and b in leaf were in the decreasing order of White, Blue, Green, Red and Yellow. There is positive correlation between chlorophyll a and chlorophyll b, and between total chlorophyll and chl:a/b ratio. Blue color shade is expected to be beneficial for ginseng production.

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Study on the Physicochemical Change of Human Hair Shaft Following Radiation with Ultraviolet (자외선 조사에 따른 모발의 물리화학적 변화에 관한 연구)

  • Chang, Byung-Soo;Na, Su-Kyong;Lee, Gui-Yeong
    • Applied Microscopy
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    • v.36 no.2
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    • pp.109-118
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    • 2006
  • The physicochemical properties of damaged hair by irradiation of ultraviolet-B (UV-B) have been investigated by using transmission electron microscope and scanning electron microscope. The range of irradiation of hair irradiated for expectative 6 hours, 12 hours, 24 hours and 48 hours with stimulated ultraviolet ray. The treated hairs showed characteristic morphological damage pattern in the cornified cell of matrix and the cuticle following time past. The various sized vacuoles in the endocuticle of the cuticular cells was formed. The statistically significant differences in diameter of cuticular cell were observed in terms of tranverse swelling by formation of vacuoles. The hair cortex and matrix undergo long term exposure to UV-B radiation. The macrofibrils of cortex appeared to be affected most by UV-B, although the morphology and volume of melanin granule was not changed. The physicochemical destruction of hair matrix and cuticular cells is largely accelerated by long term irradiation of UV-B.

Effect of Sulfur Application on Mulberry Growth and Chemical Composition of Soil and Leaf. (황시용이 뽕나무의 생육 및 토양과 뽕잎의 화학성에 미치는 영향)

  • 이원주;임수호
    • Journal of Sericultural and Entomological Science
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    • v.37 no.2
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    • pp.109-113
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    • 1995
  • Effects of sulfur application on mulberry growth and soil chemical properties were examined in mulberry trees grown in a green house. Mulberry graftages were planted in Wagner pots and sulfur was applied at the levels of 0, 30, 60, or 120 kg/10a. Mulberry stem growth increased by 3.2 cm at 30 kg/ha than at 0 kg/ha sulfur application. Stem growth, however, decreased by 3.7 cm with the application of sulfur higher than at 60 kg/10a. Soil pH changed by the application of sulfur. With the application of sulfur at 120 kg/10a, soil pH decreased by 3.0. Temporal changes in the effective from sulfur content in soil indicated that sulfur dissolved between 4 to 10 days after application in the soil. Content of moisture and chemical components in mulberry leaves was also affected by the application levels of sulfur. Moisture, total-N, No3-N, K, and S content decreased, but F and Ca content increased with the application of sulfur lower than at 60 kg/10a. With the application of sulfur higher than at 60 kg/10a, P, S, and K content increased.

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Synthesis of Polyacrylates Containing Si, Ge and Sn for High Refractive Index (실리콘, 게르마늄, 주석이 결합된 고굴절률 아크릴 고분자의 합성)

  • Maheswara, Muchchintala;Do, Jung-Yun
    • Polymer(Korea)
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    • v.34 no.6
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    • pp.588-593
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    • 2010
  • New seven acrylic monomers with covalently bonded silicon, germanium, and tin were prepared for high refractive index materials. The monomers were copolymerized with a cross-linkable comonomer (Trimer) to prepare UV-films for optical characterization. The refractive index of the copolymers increased in proportion to the monomer content and extrapolated to determine that of homopolymer. $Ph_3Si$, $Ph_3Ge$, and $Ph_3Sn$ groups contributed to increase the refractive index of acrylic polymer, in which $Ph_3Sn$ was more effective than $Ph_3Ge$. The index increment confidently occurred with $Bu_3Sn$ attachment in comparison with aliphatic acrylic polymers. $Ph_3SnS$-attached acrylate polymer showed a refractive index of 1.671 at 589 nm. The index change was similarly observed at various different wavelengths (656, 830, 1310, and 1550 nm).