• Title/Summary/Keyword: GeO$_2$

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Uptake Properties of Germanium to Vegetable Plants and Its Effect on Seed Germination and on Early Stage Growth (채소종자 발아와 유묘생장에 미치는 유기 또는 무기게르마늄의 효과 및 흡수특성)

  • Han, Myung-Ja;Kim, Sung-Un;Seo, Dong-Cheol;Cheong, Yong-Hwa;Lee, Do-Jin;Park, Moon-Su;Rim, Yo-Sup;Sohn, Bo-Kyoon;Heo, Jong-Soo;Cho, Ju-Sik
    • Korean Journal of Environmental Agriculture
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    • v.26 no.3
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    • pp.217-222
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    • 2007
  • To investigate effects of inorganic $(GeO_2)$ and organic (Ge-132) germanium (Ge) on seed germination and on early stage growth of plane and the uptake characteristics, various concentrations (0, 10, 25, 50, 100 mg $L^{-1}$) of Ge to popular vegetables such as leaf mustard, chinese cabbage and pak-choi, respectively, were treated. On seed germination, no significant effect was observed in both inorganic and organic Ge treatments except 100 mg $L^{-1}$ treatment of inorganic Ge. Exogenous inorganic Ge ($10{\sim}100$ mg $L^{-1}$ treatments significantly inhibited the early root elongation growth of all plants. However, slight enhancement of early shoot elongation was detected in low concentrations (10 and 25 mg $L^{-1}$) of Ge in the leaf mustard and chinese cabbage plants. Organic Ge treatments significantly stimulated the 개ot and shoot growth at the 10, 25 and 50 mg $L^{-1}$ treatments. Ge was accumulated linearly in the vegetables as both inorganic and organic Ge concentrations were increased. Interestingly, total contents of Ge in plants with Ge-132 treatments were $2\sim4.5$ times more than those with inorganic Ge treatments in all concentrations. At 25 mg $L^{-1}$ treatment of Ge, contents of Ge in vegetables are following: in leaf mustard, inorganic Ge: 0.37 mg $g^{-1}dw$ and organic Ge: 1.47 mg $g^{-1}dw;$ in the chinese cabbage, inorganic Ge: 0.4 mg $g^{-1}dw$ and organic Ge: 0.86 mg $g^{-1}dw;$ in the pak-choi, inorganic Ge: 0.33 mg $g^{-1}dw$ and organic Ge: 0.70 mg $g^{-1}dw$, respectively. These results showed organic Ge is much better on early stage seedling growth and on germanium accumulation of vegetables than inorganic Ge.

Thermally Expanded Core Fibers for Hybrid Fiber Components (광섬유 복합 소자를 위한 열확장코어 광섬유)

  • 김진하;김병윤
    • Korean Journal of Optics and Photonics
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    • v.5 no.2
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    • pp.304-310
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    • 1994
  • The use of thermally expanded core (TEe) fibers fabricated by thermal diffusion of dopants such as $GeO_{2}$ in hybrid fiber components has an advantage of eliminating lenses for collimation and focusing. An electric furnace is fabricated to heat the fibers locally for the core expansion. We observed an expansion of the mode size at $1.3\mu\textrm{m}$ wavelength by 27% after treating a section of single mode optical fiber at $1250^{\circ}C$ for 10 hours. hours.

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Phase Locked Loop Sub-Circuits for 24 GHz Signal Generation in 0.5μm SiGe HBT technology

  • Choi, Woo-Yeol;Kwon, Young-Woo
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.7 no.4
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    • pp.281-286
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    • 2007
  • In this paper, sub-circuits for 24 GHz phase locked 100ps(PLLs) using $0.5{\mu}m$ SiGe HBT are presented. They are 24 Ghz voltage controlled oscillator(VCO), 24 GHz to 12 GHz regenerative frequency divider(RFD) and 12 GHz to 1.5 GHz static frequency divider. $0.5{\mu}m$ SiGe HBT technology, which offers transistors with 90 GHz fMAX and 3 aluminum metal layers, is employed. The 24 GHz VCO employed series feedback topology for high frequency operation and showed -1.8 to -3.8 dBm output power within tuning range from 23.2 GHz to 26 GHz. The 24 GHz to 12 GHz RFD, based on Gilbert cell mixer, showed 1.2 GHz bandwidth around 24 GHz under 2 dBm input and consumes 44 mA from 3 V power supply including I/O buffers for measurement. ECL based static divider operated up to 12.5 GHz while generating divide by 8 output frequency. The static divider drains 22 mA from 3 V power supply.

Fabrication and analysis of Planar waveguide Bragg gratings (광도파로 격자의 제작 및 특성 분석)

  • 권재중;정재훈;정윤찬;이병호;박무윤;정선태;김현수;김민성
    • Proceedings of the Optical Society of Korea Conference
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    • 2000.02a
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    • pp.70-71
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    • 2000
  • Ge이 도핑된 실리카 광도파로 코어는 GeO$_2$분자의 산소결핍에 의하여 248nm의 파장을 갖는 자외선에 대해서 광감응성을 가지게 된다. 따라서 248nm 파장의 레이저를 간섭시켜 조사할 경우, Ge가 도핑되지 않은 overcladding 부분은 투과하고 간섭 패턴의 에너지 분포에 따라 코어의 굴절률이 주기적으로 변화한다. 이 주기적인 굴절률 변화는 잘 알려진 광학적 브래그 격자(Bragg grating)의 역할을 하게된다. 자외선 레이저를 이용하여 영구적인 굴절률 변화를 코어 내부에 형성시키는 방법으로는 홀로그램법과 위상 마스크를 이용하는 방법, 그리고 단일 슬릿을 이용하는 방법등이 있다[1][2]. (중략)

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Investigation of adsorption structure for methionine on Ge(100)

  • Yang, Se-Na;Yun, Yeong-Sang;Park, Seon-Min;Hwang, Han-Na;Hwang, Chan-Guk;Kim, Se-Hun;Lee, Han-Gil
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.369-369
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    • 2010
  • Adsorption and ordering of methionine molecules on Ge(100) surface have been studied using high resolution photoemission spectroscopy and low-energy electron diffraction (LEED) to investigate the adsorption structure as a function of coverage. Analysis of C 1s, S 2p, N 1s, and O 1s core levels reveals quite different according to methionine coverage. We found that the relative population of the two types of thiolates induces a structural change in the ordering from $2\;{\times}\;1$ to $1\;{\times}\;1$. Such an unusual evolution of the methionine adsorption on the Ge(100) surface is discussed in relation to chemical reactions and possible molecular rearrangement on the surface.

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Effects of Soil Texture on Germanium Uptake and Growth in Rice Plant by Soil Application with Germanium (게르마늄 토양처리시 토성이 벼의 생육 및 게르마늄 흡수에 미치는 영향)

  • Lim, Jong-Sir;Seo, Dong-Cheol;Park, Woo-Young;Cheon, Yeong-Seok;Lee, Seong-Tae;Cho, Ju-Sik;Heo, Jong-Soo
    • Korean Journal of Environmental Agriculture
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    • v.27 no.3
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    • pp.245-252
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    • 2008
  • The growth characteristics and the Germanium (Ge) uptake of rice plant (Hopyungbyeo) in soil with Ge were investigated under different soil textures to obtain the basic information for agricultural utilization of Ge. This study was carried out in the Wagner pot ($15,000^{-1}a$). Ge concentration in soils such as clay loam, silt loam, loam and sandy loam for rice plant cultivation was treated at $8mg\;kg^{-1}$. The growth status of rice plant was almost similar in all soil texture, and rice yield was higher in the order of silt loam > clay loam > loam > sandy loam. In rice bran, the Ge uptakes in silt loam, clay loam, loam and sandy loam were 980, 868, 754 and $803{\mu}g\;pot^{-1}$, respectively. The Ge uptakes of brown rice and polish rice were greater in the order of silt loam > sandy loam > clay loam > loam. In silt loam, the Ge uptake rates in leaf, stem, root, rice bran and brown rice were 19.7, 2.3, 0.03, 3.1 and 0.44%, respectively. Therefore, under the given experimental condition the optimum soil texture for production of functional rice with Ge is a silt loam.

Synthesis and Luminescent Property Investigation of the $Mg_4GeO_2:Mn$ for LEDs

  • Lee, Seung-Jae;Park, Joung-Kyu;Kim, Kyung-Nam;Bae, Pan-Kee;Kim, Chang-Hae;Chang, Hyun-Ju;Kim, Yong-Rok
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1526-1528
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    • 2007
  • In this report, Manganese doped magnesium germanate ($Mg_4GeO_2:Mn$) phosphor has been synthesized by the solid state method. Also, this phosphor was prepared by simple process under an air atmosphere for oxidation of Mn. The prepared phosphor shows a main luminescent peak at 661nm. Therefore, this phosphor is possible to be applicable to white LED lamp by GaN or InGaN chips.

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Fabrication of Low Loss Silica Slab Waveguide by Flame Hydrolysis Deposition (FHD 공정에 의한 저손실 실리카 슬랩 도파로 형성)

  • 심재기;김태홍;신장욱;박상호;김덕준;성희경
    • Journal of the Korean Ceramic Society
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    • v.37 no.6
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    • pp.524-529
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    • 2000
  • Silica slab wavegudie was fabricated on Si substrates by FHD for planar optical passive devices. The slab waveguide consists of lower clad and core layers, where core layer index is controlled by GeO2 addition. Doping of GeO2 in silica is difficult because of the low deposition density due to nonspherical particle generation in FHD process. Silica core particles deposited at various conditions such as flame temperature and substrate scanning were analyzed by SEM and TEM. As the flame temperature increased, the surface roughness of the core layer was decreased up to 3.6 nm after consolidation. Index difference and thickness of core of slab waveguide were 0.3%, 8$\mu\textrm{m}$ respectively. Measured optical loss at TE mode was <0.04 dB/cm at 1.3$\mu\textrm{m}$ and <0.06 dB/cm at 1.55$\mu\textrm{m}$.

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Synthesis and Characterization of Langastie-type Materials

  • An, Jin-Ho;Yoon, Won-Ki;Kynug Joo;Auh, Keun-Ho
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1998.06a
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    • pp.115-119
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    • 1998
  • Possibilities of substitution was investigated in the Langadite({{{{ {La }_{3 } {Ga }_{ 5}{SiO }_{14 }}}}}) system.{{{{{TiO}_{2 }}}}} was substitutes for{{{{{SiO}_{2 }}}}} followed by the substitution of{{{{{Nd}_{2 }{O}_{3}}}}}fo{{{{{La}_{2 }{O}_{3}}}}}. An effort to replace GeO2, which is reported to have been substitution for{{{{{SiO}_{2 }}}}} in the Langasit e system, for{{{{{TiO}_{2 }}}}} i n{{{{{ Nd}_{ 3} {Ga }_{5 } {TiO }_{14 } }}}} was also undertaken. In another experiment,{{{{{ Y}_{ 2}{ O}_{3 } }}}} was substituted for{{{{{ La}_{2 } {O }_{ 3} }}}}. All of substitution possibilities were investigated through solid state reactions and analyzed with XRD. Further analysis was carried out with an SEM. Lastly, the dielectric constants of the sintered body were measured.

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