• 한국재료학회지
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• 제9권12호
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• pp.1155-1159
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• 1999

플라즈마 화학증착 (PECVD) 장비를 이용하여 $SnO_2$ 투명전도막이 피막된 유리기판 위에 p-SiC/i-Si/n-Si 이종접합 태양전지를 제작하였다. p-SiC 층의 증착중에 기체조성 x=$CH_4/\;(SiH_4+CH_4)$의 변화에 대한 태양전지의 광기전 특성을 관찰하였다. 기체조성(x)이 0~0.4의 범위에서 p-SiC 창층의 광학적 밴드갭의 증가로 인하여 태양전지의 효율은 증가하였으나, 그 이상의 기체조성에서는 p-SiC/i-Si 계면에서의 조성불일치가 증가하여 태양전지의 효율이 감소하였다. 이러한 계면문제는 p-SiC 층과 i-Si 계면에서의 조성불일치가 증가하여 태양전지의 효율이 감소하였다. 이러한 계면문제는 p-SiC 층과 I-Si 층 사이에 I-SiC 완충층을 삽입함으로써 크게 감소하였다. 그 결과 유효면적이 $1cm^2$인 glass/$SnO_2$/p-SiC/i-SiC/i-Si/n-Si/Ag 구조의 박막 태양전지는 100mW/$cm^2$ 조도 하에서 8.6%의 효율을 나타내었다. ($V_{oc}$=0.85V, $J_{sc}$=16.42mA/$cm^2$, FF=0.615)

• 한국소음진동공학회논문집
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• 제16권8호
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• pp.864-871
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• 2006

In the development of electricity generating wind turbines for wind farm application, only two types have survived as the methods of power regulation; stall regulation and full span pitch control. The main purpose of this paper is to experimentally identify the characteristics of noise emission of wind turbines according to the power regulation types. The sound measurement procedures of IEC 61400-11 are applied to field test and evaluation of noise emission from each of 1.5 MW and 660 kW wind turbines (WT) utilizing the stall regulation and the pitch control for the power regulation, respectively. Apparent sound power level, wind speed dependence, third-octave band levels and tonality are evaluated for both of WTs. It is observed that equivalent continuous sound pressure levels (ECSPL) of the stall control type of WT continue to increase with increasing wind speed whereas those of the pitch control type of WT show less correlation with wind speed. These observed characteristics are believed to be due to the different airflow patterns around the blade between the stall regulation and the pitch control types of WT; the airflow on the suction side of blade in the stall types of WT are separated at the high wind speed. It is also found that the 1.5 MW WT using the stall control emits lower sound power than 660 kW one using the pitch control at wind speeds below 8m/s, whereas sound power of the former becomes higher than that of the latter in the wind speed over 8m/s. This wind-speed dependence of sound power leads to the very different noise omission characteristics of WTs depending on the seasons because the average wind speed in summer is lower than 8m/s whereas that in summer is higher. Based on these experimental observations, it is proposed that, in view of environmental noise regulation, the developer of wind farm should give enough considerations to the choice of power regulation of their WTG based on the weather conditions of potential wind farm locations.

• 한국전자파학회논문지
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• 제30권4호
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• pp.282-285
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• 2019

본 연구에서는 2단계 게이트 리세스 방법을 사용하여 T-형 게이트 길이가 100 nm인 mHEMT 소자를 제작하였다. 제작한 소자는 65 mA의 드레인전류($I_{dss}$), 1090 mS/mm의 트랜스콘덕턴스($g_m$), -0.65 V의 문턱전압 ($V_{th}$) 등의 DC 특성을 보였다. 또한 차단주파수($f_T$) 190 GHz와 최대 공진주파수($f_{MAX}$) 260 GHz인 우수한 고주파 특성을 나타내었다. 제작한 mHEMT 소자는 향후에 W-대역의 MMIC 개발에 활용될 수 있을 것으로 기대된다.

• 현장농수산연구지
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• 제11권1호
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• pp.53-61
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• 2009

본 연구는 개발된 밀리타리스 동충하초 균사체를 비육후기 한우에 사료경제적인 한계의 최고점에서 일정기간 급여하여 균사체내에 존재하는 cordycepin이 한우 조직내에 존재하는 지와 혈중 항산화활성의 증가를 확인하기 위하여 수행하였다. 본 연구는 비육후기 거세한우 4두를 공시하여 대조구와 처리구 각각 2두씩 배치하고, 처리구의 균사체 첨가수준은 사료섭취량의 1%로 정하여 80일간 사양하였다. 사양후 도축하여 근육(후지)을 취하여 이들내 cordycepin을 TLC상에서 전개하고, 혈액을 채취하여 혈장내 항산화효소인 GSH-Px활성을 조사하였다. 본 연구에서 얻어진 결과를 살펴보면, 종료체중, 건물섭취량, 중체량은 대조구 및 밀리타리스 동충하초 균사체급여군간에 유의한 차이가 나타나지 않았다. 혈장내 GSH-Px활성은 처리구가 15.70 unit로서 대조구의 9.23 unit보다 높은 항산화도를 나타내었으나, 통계적으로 유의한 차이는 나타나지 않았다. 근육내 cordycepin의 전이는 곡립 밀리타리스 동충하초 균사체 급여군에서 TLC상 band가 확인되었다. 이상의 결과로부터 밀라티리스 동충하초 균사체를 비육후기 거세우에 급여하였을 때 비록 유의성은 나타나지 않았지만, 항산화 기능이 어느 정도 있는 것으로 확인되었고, 처리군의 근육에서 cordycepin이 확인되었다. 따라서, 곡립 밀리타리스 동충하초 균사체를 한우에 급여하면 조직 내의 cordycepin의 전이가 가능한 것으로 사료된다.

• 한국재료학회지
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• 제13권3호
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• pp.185-190
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• 2003

Titanium dioxide films were prepared by RF sputtering method on glass for various oxygen partial pressures at power 270 W. The crystal structure, photocatalytic property and the hydrophilicity of $TiO_2$thin film the deposition conditions were investigated. Crystallized anatase phase was observed in $TiO_2$film deposited at the ratio of oxygen partial pressure 10% and 20% for 2 hrs. As the increase of deposition time, the grain size and void size of $TiO_2$film have increased and also $V_2$films have been good crystallinity. The ultraviolet-visible light absorption of $TiO_2$films was increased with increasing of deposition time and occured chiefly at the wavelength between 280 and 340 nm. The absorption band was shifted to a longer wave length as deposition time increased. Water contact angle on the X$TiO_2$film of anatase structure was decreased with increasing ultraviolet illumination time and became lower than $11^{\circ}$ from $83^{\circ}$. When hydrophilic $TiO_2$film changed by enough ultraviolet illumination was stored in the dark, the film surface gradually turned to hydrophobic state.

• The Plant Pathology Journal
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• 제21권2호
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• pp.167-171
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• 2005

We isolated the Cucumber green mottle mosaic virus(CGMMV) particles from watermelon leaves and designated as CGMMV-HY1 as a watermelon isolate and attempted to characterize the pathogenic isolate responsible for such an epidemic in watermelon and also to monitor dominant viral isolates in greenhouse. The watermelon plants infected with CGMMV generally showed mottle mosaic, mosaic, growth stunting, necrosis and deformed fruit. The reactions of indicator plants to CGMMV-HY1 were the local lesions on Nicotiana tabacum cv. White Burley, Nicotiana tabacum cv. Samsun, and Chenopodium amaranticola, and the mosaic symptoms only on Cucumis sativus, but the CGMMV-HY1 did not infect Nicotiana sylvesytis, Datura stramonium, Chenopodium quinoa, and Petunia hybrida. Purified virus particles were rod-shaped and about 300 nm long. The coat protein (CP) of purified CGMMV-HY1 was single band with molecular weight of about 16.5 kDa which was confirmed by western blot analysis probed with monoclonal antibody of CGMMV-HY1. The genomic and subgenomic RNAs of 6.4 kb and 0.75 kb were revealed by the electrophoresis on 1.2% formaldehydedenatured agarose gel. Viral and complementary CGMMV-specific primer sets were designed for spanning the genome using previously reported CGMMV sequences. A 464bp of CP gene of CGMMV-HY1 was amplified by RT-PCR and cloned into PGEM-T easy vector. The nucleotide sequence of CP gene of CGMMV-HY1 shared 98%, 99%, and 100% identities with that of CGMMV strains W, KOM, and KW respectively. Based on these results, we identified CGMMV-HY1 as a CGMMV isolate of watermelon, a member of Tobamovirus.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3355-3360
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• 2012

To promote the photoelectric conversion efficiency of dye-sensitized solar cells (DSSCs), graphene is introduced as a working electrode with $TiO_2$ in this study, because it has great transparency and very good conductivity. XRD patterns indicate the presence of graphene and $TiO_2$ particles in graphene-linked $TiO_2$ samples. Moreover, TEM pictures also show that the nano-sized $TiO_2$ particles are highly dispersed and well-linked onto the thin layered graphene. On the basis of the UV-visible spectra, the band gaps of $TiO_2$, 1.0 wt % graphene-$TiO_2$, 5.0 wt % graphene-$TiO_2$, and 10.0 wt % graphene-$TiO_2$ are 3.16, 2.94, 2.25, and 2.11 eV, respectively. Compared to pure $TiO_2$, the energy conversion efficiency was enhanced considerably by the application of graphene-linked $TiO_2$ anode films in the DSSCs to approximately 6.05% for 0.1 wt % graphene-$TiO_2$ with N719 dye (10.0 mm film thickness and $5.0mm{\times}5.0mm$ cell area) under $100mW/cm^2$ of simulated sunlight. The quantum efficiency was the highest when 1.0 wt % of graphene was used. In impedance curves, the resistance was smallest for 1.0 wt % graphene-$TiO_2$-DSSC.

• Bulletin of the Korean Chemical Society
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• 제35권5호
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• pp.1485-1490
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• 2014

We have designed and developed a new ladder type tetrafused ${\pi}$-conjugated building block such as dihydroindolo[3,2-b]indole (DINI) and investigated its role as an electron rich unit. The photovoltaic properties of a new semiconducting ${\pi}$-conjugated polymer, poly[[5,10-bisoctyl-5,10-dihydroindolo[3,2-b]indole-[5,6- bis(octyloxy)-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole]], represented by PDINI-OBTC8 are described. The new polymer PDINI-OBTC8 was synthesized in donor-acceptor (D-A) fashion, where fused ${\pi}$-conjugated tetracyclic DINI, and 5,6-bis(octyloxy)-4,7-di(thiophen-2-yl) benzo[c][1,2,5]thiadiazole (OBTC8) were employed as electron rich (donor) and electron deficient (acceptor) moieties, respectively. The conventional bulk heterojunction (BHJ) device structure ITO/PEDOT:PSS/PDINI-OBTC8:PCB71M/LiF/Al was utilized to fabricate polymer solar cells (PSCs), which comprises the blend of PDINI-OBTC8 and [6,6]-phenyl-$C_{71}$-butyric acid methyl ester ($PC_{71}BM$) in BHJ network. A BHJ PSC that contain PDINI-OBTC8 delivered power conversion efficiency (PCE) value of 1.68% with 1 vol% of 1,8-diidooctane (DIO) under the illumination of A.M 1.5G 100 $mW/cm^2$.

• Asian-Australasian Journal of Animal Sciences
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• 제19권11호
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• pp.1519-1523
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• 2006

Through a screening and selection approach method, decamer random markers were used in a technique called random amplified polymorphic DNA (RAPD) assay with 252 genomic DNAs isolated from four major Haimen chicken populations: Rugao (62), Jiangchun (62), Wan-Nan (63) and Cshiqishi (65). A total of 3-score decamer random primers (S241-S260, S1081-S1100 and S1341-S1360) were employed in the preliminary RAPD-polymerase chain reaction (RAPD-PCR) assay with 50 random template DNA samples from all the populations. Four (6.67%) of the primers that produced obvious polymorphic patterns, interpretable and reproducible bands were selected and used with both the individual DNAs from each population and with pooled DNA samples of the four populations in subsequent analyses. The selected primers produced a total of 131 fragments with molecular size ranging from 835 to 4,972 base pairs (bp) when used with the individual DNAs; 105 (80.15%) of these fragments were polymorphic. With the pooled DNAs, 47 stable and characteristic bands with molecular size ranging from 840 to 4,983 bp, of which 23 (48.94%) polymorphic, were also generated. The band-sharing coefficient (BSC) calculated for the individuals in the population and among populations of bulked samples was between 0.8247 (Rugao) and 0.9500 (Cshiqishi); for pairwise populations, it was between 0.7273 (Rugao vs. Wan-Nan) and 0.9367 (Jiangchun vs. Cshiqishi) chicken populations. Using the BSC for individual and pairwise populations, the Nei's standard genetic distances between the chicken populations were determined and ranged from 0.0043 (Jiangchun vs. Cshiqishi) to 0.1375 (Rugao vs. Cshiqishi). The reconstructed dendrogram linked the Jiangchun and Cshiqishi chickens as closely related populations, followed by Wan-Nan, while the Rugao was the most genetically distant among the populations.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.306.1-306.1
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• 2016

ZnO semiconductor material has been widely utilized in various applications in semiconductor device technology owing to its unique electrical and optical features. It is a promising as solar cell material, because of its low cost, n-type conductivity and wide direct band gap. In this work ZnO/Si heterojunctions were fabricated by using pulsed laser deposition. Vacuum chamber was evacuated to a base pressure of approximately $2{\times}10^{-6}Torr$. ZnO thin films were grown on p-Si (100) substrate at oxygen partial pressure from 5mTorr to 40mTorr. Growth temperature of ZnO thin films was set to 773K. A pulsed (10 Hz) Nd:YAG laser operating at a wavelength of 266 nm was used to produce a plasma plume from an ablated a ZnO target, whose density of laser energy was $10J/cm^2$. Thickness of all the thin films of ZnO was about 300nm. The optical property was characterized by photoluminescence and crystallinity of ZnO was analyzed by X-ray diffraction. For fabrication ZnO/Si heterojunction diodes, indium metal and Al grid patterns were deposited on back and front side of the solar cells by using thermal evaporator, respectively. Finally, current-voltage characteristics of the ZnO/Si structure were studied by using Keithly 2600. Under Air Mass 1.5 Global solar simulator with an irradiation intensity of $100mW/cm^2$, the electrical properties of ZnO/Si heterojunction photovoltaic devices were analyzed.