• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.44-44
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• 2021

본 연구는 제주지역의 골프 코스에서 하절기 고온기간에 온도의 상승을 비롯한 다양한 환경변화로 인하여 생육 장애가 심한 한지형 잔디인 perennial ryegrass (Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.), creeping bentgrass (Agrostis palustris Huds.) 3종에 대하여 엽록소형광과 엽록소지수를 측정하여 골프 코스와 스포츠 필드에서 잔디 선정과 관리를 위한 기본적인 정보를 얻기 위하여 수행하였다. F_o 값은 3종 모두 하절기 초기에는 낮고 후기에 다소 증가하는 양상을 보였다. 그러나, perennial ryegrass의 경우는 하절기 초기와 후기 간의 F_o 값의 변화가 컸으며, 특히, 후기에 F_o 값은 다른 2종 월등하게 보다 높았다. F_m 값은 3종 모두 하절기 초기에는 낮고 하절기 후기에 증가하였으나 3종 간의 차이는 크지 않았다. 광계 II의 광화학적 효율의 척도인 F_v/F_m 값은 3종 모두에서 하절기 초기에 낮고, 후기에 다소 증가하는 양상을 보였으나, 하절기 후기에 Kentucky bluegrass와 creeping bentgrass는 perennial ryegrass에 비해 F_v/F_m 값이 다소 높아 하절기 고온에서도 보다 더 잘 적응하는 것으로 보인다. 엽록소지수는 perennial ryegrass와 Kentucky bluegrass에서는 뚜렷하게 하절기 초기에는 낮고 후기에 높은 양상을 보였으나, creeping bentgrass는 조사기간 내내 낮은 상태를 유지하였다. 이상의 결과로부터 Kentucky bluegrass가 하절기 후기의 고온이나 빈번한 강우에 의한 습한 조건에 가장 강하고, perennial ryegrass가 가장 취약한 것으로 사료된다.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.12-15
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• 2000

In this paper, we have fabricated the PHEMT's with AlGaAs/InGaAs/GaAs and measured characteristics of DC and frequencies. The PHEMT's has a 0.35$\mu\textrm{m}$ gate length, gate width of 60$\mu\textrm{m}$ and 80$\mu\textrm{m}$, and fingers of 2 and 4. From the measurements results for the 60$\mu\textrm{m}$ ${\times}$ 2 PHEMT's, we obtained 1.2V of Vk, -3.5V of Vp, 46mA of Idss, 221mS/mmof gm, and 3.6dB of S$\sub$21/ gain, 45GHz of f$\sub$T,/ 100GHz of fmax. And, in case of 80$\mu\textrm{m}$ ${\times}$ 4 PHEMT's, we obtained 1.2V of Vk, -4.5V of Vp, 125mA of Idss, 198mS/mm of gm, and 2.0dB of S$\sub$21/ gain. 44GHz of f$\sub$T/, 70GHz of fmax at 35GHz frequency. Also, MAG are decreased as a number of finger are Increased.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1501-1511
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• 2015

As essential trace elements, copper and zinc play important roles in many physiological events in plants. In excess, however, these elements can limit plant growth. This study selected a heavy metal-tolerant plant by analyzing seed germination and biomass of alfalfa (Medicago sativa), canola (Brassica campestris subsp. napus var. nippo-oleifera), Chinese corn (Setaria italica), and a sorghum-sudangrass hybrid (Sorghum bicolor ${\times}$ S. sudanense), and determined heavy metal uptake capacity by analyzing biomass, chlorophyll a fluorescence, and heavy metal contents under high external copper or zinc levels. The seed germination rate and biomass of the sorghum-sudangrass hybrid were higher under copper or zinc stress compared to the other three plants. The plant biomass and photosynthetic pigment contents of the sorghum-sudangrass hybrid seedlings were less vulnerable under low levels of heavy metals (${\leq}50ppm$ copper or ${\leq}400ppm$ zinc). The maximum quantum yield of PSII ($F_v/F_m$) and the maximum primary yield of PSII ($F_v/F_o$) decreased with increasing copper or zinc levels. Under high copper levels, the decline in $F_v/F_m$ was caused only by the decline in $F_m$, and was accompanied by an increase in non-photochemical quenching (NPQ). The $F_v/F_m$ declined under high levels of zinc due to both a decrease in the maximum fluorescence ($F_m$) and an increase in the initial fluorescence ($F_o$), and this was accompanied by a marked decrease in photochemical quenching (qP), but not by an increase in NPQ. Accumulations of copper and zinc were found in both aboveand below-ground parts of plants, but were greater in the below-ground parts. The uptake capacity of the sorghum-sudangrass hybrid for copper and zinc reached 4459.1 mg/kg under 400 ppm copper and 9028.5 mg/kg under 1600 ppm zinc. Our results indicate that the sorghum-sudangrass hybrid contributes to the in situ phytoremediation of copper or zinc polluted soils due to its high biomass yield.

• Korean Journal of Microbiology
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• v.36 no.4
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• pp.259-266
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• 2000

Spheroplast cell fusions were performed with Flavimonas oryzihabitans degrading aniline and Pseudomonas sp. degrading 4-chlorobiphenyl to develope the new fusant degrading aniline and 4-CBP and its characters were investigated. F. oryzihabitans was induced to antibiotic marker ($Cm^r$ by NTG treatment for the fusants selection. The results of spheroplast formation and regeneration frequencies of the strains treated with lysozyme-EDTA were 99% and 5.0~6.6%, respectively. Fusion products were treated with 40% (v/v) PEG 6000 and fusion frequency was $3.16{\times}10^{-4} $. The DNA content of fusant, F22 was approximately 2-fold compared with parents. The fusant was stable, and showed the mixed biochemical characteristics of the parent strains. F22 was similar to parent for cell growth pattern and degrading capacity on 5 mM aniline but cell growth rate of F22 was 1.5-fold higher than that of the parent on 10mM aniline. However 4-CBP degrading ability of F22 was slightly lower than that of parental strain.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.548-551
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• 2000

Spinel phase LiF $e_{y}$M $n_{2-y}$ $O_4$samples are synthesized by calcining a LiOH.$H_2O$, Mn $O_2$and F $e_2$ $O_3$mixture at 80$0^{\circ}C$ for 36h in air. Preparing LiF $e_{y}$M $n_{2-y}$ $O_4$showed spinel phase with cubic phase. The ununiform distortion of the crystallite of the spinel LiF $e_{y}$M $n_{2-y}$ $O_4$was more stable than that of the pure. The discharge capacity of the cathode for the Li/LiF $e_{0.1}$M $n_{1.9}$ $O_4$cell at the first than that of the pure. The discharge capacity of the cathode for the Li/LiF $e_{0.1}$M $n_{1.9}$ $O_4$cell at the first cycle and at the 70th cycle was about 113 and 90mAh/g, respectively. This cell capacity was retained about 82% of the first cycle after 70th cycle. Impedance profile of this cell was more stable than that pure. The resistance, the capacitance and chemical diffusion coefficients of lithium ion showed approximately 80$\Omega$, 36133.87$\mu$F ; 1.4$\times$10$^{-8}$ c $m^2$ $s^{-1}$ , respectively. , respectively.ely.

• Transactions on Electrical and Electronic Materials
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• v.8 no.4
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• pp.174-177
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• 2007

We fabricated organic field-effect transistors (OFETs) based a fluorinated copper phthalocyanine ($F_{16}CuPC$) and copper phthalocyanine (CuPc) as an active layer. And we observed the surface morphology of the $F_{16}CuPC$ thin film. The $F_{16}CuPC$ thin film thickness was 40 nm, and the channel length was $50{\mu}m$, channel width was 3 mm. And we also fabricated the $F_{16}CuPc/CuPc$ double layer FET and with different $F_{16}CuPc$ film thickness devices. We observed the typical current-voltage (I-V) characteristics and capacitance-voltage (C-V) in $F_{16}CuPc$ FET and we calculated the effective mobility. From the double layer FET devices, we observed the higher drain current more than single layer FET devices.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.142.2-142.2
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• 2007

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.319-322
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• 2003

To match the charge induced by the insulators $CeO_2$ with the remanent polarization of ferro electric SBT thin films, areas of Pt/SBT/Pt (MFM) and those of $Pt/CeO_2/Si$ (MIS) capacitors were ind ependently designed. The area $S_M$ of MIS capacitors to the area $S_F$ of MFM capacitors were varied from 1 to 10, 15, and 20. Top electrode Pt and SBT layers were etched with for various area ratios of $S_M\;/\;S_F$. Bottom electrode Pt and $CeO_2$ layers were respectively deposited by do and rf sputtering in-situ process. SBT thin film were prepared by the metal orgnic decomposition (MOD) technique. $Pt(100nm)/SBT(350nm)/Pt(300nm)/CeO_2(40nm)/p-Si$ (MFMIS) gate structures have been fabricated with the various $S_M\;/\;S_F$ ratios using inductively coupled plasma reactive ion etching (ICP-RIE). The leakage current density of MFMIS gate structures were improved to $6.32{\times}10^{-7}\;A/cm^2$ at the applied gate voltage of 10 V. It is shown that in the memory window increase with the area ratio $S_M\;/\;S_F$ of the MFMIS structures and a larger memory window of 3 V can be obtained for a voltage sweep of ${\pm}9\;V$ for MFMIS structures with an area ratio $S_M\;/\;S_F\;=\;6$ than that of 0.9 V of MFS at the same applied voltage. The maximum memory windows of MFMIS structures were 2.28 V, 3.35 V, and 3.7 V with the are a ratios 1, 2, and 6 at the applied gate voltage of 11 V, respectively. It is concluded that ferroelectric gate capacitors of MFMIS are good candidates for nondestructive readout-nonvolatile memories.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.21-33
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• 2012

Survey on the phytoplankton community structure and distribution in the upstream watershed of the East River was carried out during the period from May, 2008 to April, 2009. A total composition of phytoplankton included 159 taxa, consisting of 7 orders, 56 genera, 139 species, and 40 unidenfied species. Among those, the diatoms and green algae were more frequently found during the investigation than the other taxa. Cocconeis placentula, Cymbella minuta, Diatoma vulgare, Melosira varians, Navicula cryptocephala, Scenedesmus acuminatus v. acuminatus, were among the most common. The standing crops of the phytoplankton ranged from 86 cells $mL^{-1}$ to 1,467 cells $mL^{-1}$. The dominant species were Achnanthes minutissima, Asterionella formosa, Aulacoseira ambigua, Cocconeis placentula, Coelastrum microporum, Cyclotella sp., Cymbella affinis, C. minuta, C. tumida, Diatoma vulgare, Fragilaria capucina, F. construens, F. crotonensis, Gomphonema affine, G. clevei, Melosira varians, Merismopedia elegans, Navicula cryptocephala, N. pupula, Nitzschia tryblionella, Oscillatoria anna, O. limosa, O. tenuis v. tenuis, Pediastrum duplex v. reticulatum, Phormidium tenue, Scenedesmus acuminatus v. acuminatus, S. acutus v. acutus, S. ecornis v. ecornis, S. quadricauda v. quadricauda, Spirogyra sp., Stigeoclonium sp., Synedra acus, S. ulna, and Ulothrix sp. The most dominant species was Cymbella minuta. The diversity index, evenness index, and dominance index ranged from 1.58 to 3.10, 051 to 0.95, and 0.22 to 0.74, respectively. The phytoplankton community structure of upstream stations of the survey area was influenced by the effluent of the Doam Lake.

• Journal of the Korean Ceramic Society
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• v.37 no.6
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• pp.552-558
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• 2000

LiMn2O4 thin fiolm cathodes for Li-ion secondary battery were fabricated by r.f. magnetron sputtering technique. As-deposited films were amorphous. A spinel structure could not be obtained LiMn2O4 films by in-situ thermal annealing. After post thermal annealing over $700^{\circ}C$ in oxygen atmosphere, LiMn2O4 films prepared above 100 W r.f. power could be crystallized into a spinel structure. The electrochemical property of the LiMn2O4 film cathodes was tested in a Li/1 M LiClO4 in PC/LiMn2O4 cell. From cyclic voltammetry at scan rate of 2mV/sec of 2.5~4.5V, LiMn2O4 electrode prepared by post annealing at 75$0^{\circ}C$ showed good initial capacity. LiMn2O4 electrode prepared by post annealing at 80$0^{\circ}C$ showed the best crycling performance.