• Title/Summary/Keyword: Solar Concentration

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Fabrication and Characterization of $CuInSe_2$Thin Films from $In_2Se_3$ and$Cu_2Se$Precursors ($In_2Se_3$$Cu_2Se$를 이용한 $CuInSe_2$박막제조 및 특성분석)

  • Heo, Gyeong-Jae;Gwon, Se-Han;Song, Jin-Su;An, Byeong-Tae
    • Korean Journal of Materials Research
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    • v.5 no.8
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    • pp.988-996
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    • 1995
  • CuInSe$_2$this films as a light absorber layer were fabricated by vacuum evaporation using In$_2$Se$_3$and Cu$_2$Se precursors and their properties were analyzed. Indium selenide films of 0.5${\mu}{\textrm}{m}$ thickness were first deposited by vacuum evaporation of In$_2$Se$_3$ on a Corning 7059 glass substrate. The films deposited at suscepor temperature of 40$0^{\circ}C$ showed a flat surface morphology with densely Packed grain structure. CuInSe$_2$films directly formed by evaporating Cu$_2$Se on the predeposited In$_2$Se$_2$films also showed a very flat surface when the susceptor temperature was $700^{\circ}C$. Cu$_2$Se, a second phase in the CuInSe$_2$film, was removed by evaporating additional In$_2$Se$_3$on the CuInSe$_2$film at $700^{\circ}C$. The grain size of 1.2${\mu}{\textrm}{m}$ thick CuInSe$_2$, film was about 2${\mu}{\textrm}{m}$ and the film had a (112) preferred orientation. As the amount of deposited In$_2$Se$_3$increased, the electrical resistivity of CuInSe$_2$films increased because of the decrease of hole concentration. But the optical band gap was almost constant at the value of 1.04eV, The CuInSe$_2$film grown on a Mo/glass substrate had a similar smooth microstructure compared to that on a glass substrate. A solar cell with ZnO/CdS/CuInSe$_2$/Mo structure may be realized based on the above CuInSe$_2$films.

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Antioxidative Activities of Aronia melanocarpa Fruit and Leaf Extracts (아로니아 베리 열매 및 잎 추출물의 항산화 활성)

  • Lee, Hye Mi;Kong, Bong Ju;Kwon, Soon Sik;Kim, Kyeong Jin;Kim, Hae Soo;Jeon, So Ha;Ha, Ji Hoon;Kim, Jin-Sook;Park, Soo Nam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.39 no.4
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    • pp.337-345
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    • 2013
  • In this study, the antioxidative effects of Aronia melanocarpa fruit and leaf extracts were investigated. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities ($FSC_{50}$) of the ethylacetate and aglycone fractions of fruit extracts were 16.29 ${\mu}g/mL$, and 12.29 ${\mu}g/mL$, respectively. The free radical scavenging activity of fruit extract was higher than that of leaf extracts. Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of the ethylacetate and aglycone fractions of fruit extracts on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system using the luminol-dependent chemiluminescence assay showed 2.86 ${\mu}g/mL$, and 1.80 ${\mu}g/mL$, respectively. ROS scavenging activity of the aglycone fraction of fruit extracts was similar to that of L-ascorbic acid (1.50 ${\mu}g/mL$). The ROS scavenging activity of fruit extracts was higher than that of leaf extracts. The cellular protective effects of aglycone fraction of fruit extracts (${\tau}_{50}$ = 72.3 min) on the $^1O_2$-induced cellular damage of human erythrocytes especially were increased in a concentration dependent manner (5 ~ 50 ${\mu}g/mL$). ${\tau}_{50}$ (72.3 min) of the aglycone fraction showed 1.9 times higher than (+)-${\alpha}$-tocopherol (38 min), known as lipophilic antioxidant at 10 ${\mu}g/mL$. These results incidicate that A. melanocarpa fruit extracts have higher antioxidant effects than leaf extracts and could be applicable to functional cosmetics materials for antioxidants by protecting skin exposed to solar UV radiation against ROS including $^1O_2$.

Introduction on the Products and the Quality Management Plans for GOCI-II (천리안 해양위성 2호 산출물 및 품질관리 계획)

  • Lee, Sun-Ju;Lee, Kyeong-Sang;Han, Tae Hyun;Moon, Jeong-Eon;Bae, Sujung;Choi, Jong-kuk
    • Korean Journal of Remote Sensing
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    • v.37 no.5_2
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    • pp.1245-1257
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    • 2021
  • GOCI-II, succeeding the mission of GOCI, was launched in February 2020 and has been in regular operation since October 2020. Korea Institute of Ocean Science and Technology (KIOST) processes and produces in real time Level-1B and 26 Level-2 outputs, which then are provided by Korea Hydrographic and Oceanographic Agency (KHOA). We introduced current status of regular GOCI-II operation and showed future improvement. Basic GOCI-II products including chlorophyll-a, total suspended materials, and colored dissolved organic matter concentration, are induced by OC4 and YOC algorithms, which were described in detail. For the full disk (FD), imaging schedule was established considering solar zenith angle and sun glint during the in-orbital test, but improved by further considering satellite zenith angle. The number of slots satisfying the condition 'Best Ocean' significantly increased from 15 to 78. GOCI-II calibration requirements were presented based on that by European Space Agency (ESA) and candidate fixed locations for calibrating local observation area were. The quality management of FD uses research ships and overseas bases of KIOST, but it is necessary to establish an international calibration/validation network. These results are expected to enhance the understanding of users for output processing and help establish detailed plans for future quality management tasks.

Cultivation Demonstration of Paprika (Capsicum annuum L.) Cultivars Using the Large Single-span Plastic Greenhouse to Overcome High Temperature in South Korea (고온기 대형 단동하우스를 이용한 파프리카 품종별 재배실증)

  • Yeo, Kyung-Hwan;Park, Seok Ho;Yu, In Ho;Lee, Hee Ju;Wi, Seung Hwan;Cho, Myeong Cheoul;Lee, Woo Moon;Huh, Yun Chan
    • Journal of Bio-Environment Control
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    • v.30 no.4
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    • pp.429-440
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    • 2021
  • During the growing period, the integrated solar radiation inside the greenhouse was 12.7MJ·m-2d-1, and which was 90% of the average daily global radiation outside the greenhouse, 14.1MJ·m-2d-1. The 24-hour average temperature inside the greenhouse from July to August, which has the highest temperature of the year, was 3.04℃ lower than the outside temperature, and 4.07℃ lower after the rainy season. Before the operation of fog cooling system, the average daily RH (%) was lowered to a minimum of 40% (20% for daytime), making it inappropriate for paprika cultivation, but after the operation of fog system, the daily RH during the daytime increased to 70 to 85%. The average humidity deficit increased to a maximum of 12.7g/m3 before fog supply, but decreased to 3.7g/m3 between July and August after fog supply, and increased again after October. The daytime residual CO2 concentration inside the greenhouse was 707 ppm on average during the whole growing period. The marketable yield of paprika harvested from July 27th to November 23rd, 2020 was higher in 'DSP-7054' and 'Allrounder' with 14,255kg/10a and 14,161kg/10a, respectively, followed by 'K-Gloria orange', 'Volante' and 'Nagono'. There were significant differences between paprika cultivars in fruit length, fruit diameter, soluble solids (°Brix), and flash thickness (mm) of paprika produced in summer season at large single-span plastic greenhouse. The soluble solids content was higher in the orange cultivars 'DSP-7054' and 'Naarangi' and the flesh thickness was higher in the yellow and orange cultivars, with 'K-Gloria orange' and 'Allrounder' being the thickest. The marketable yield of paprika, which was treated with cooling and heating treatments in the root zone, increased by 16.1% in the entire cultivars compared to the untreated ones, increased by 16.5% in 'Nagano', 10.3% in the 'Allrounder', 20.2% in the 'Naarangi', and 17.3% in 'Raon red'.