• Title/Summary/Keyword: $EtNH_2$ sensing

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Synthesis and Properties of New Phthaloperinone Dyes (신규 Phthaloperinone 색소의 합성과 특성에 대한 연구)

  • Jun, Kun;Gwon, Seon Yeong;Kim, Sung Hoon
    • Textile Coloration and Finishing
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    • v.27 no.4
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    • pp.275-280
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    • 2015
  • New series of phthaloperinone dyes were synthesized by the condensation reaction between tetrachloro-phthalic anhydride, 2,3-naphthalene dicarboxylic anhydride and o-phenylenediamine, 1,8-diaminonaphthalene, 1,2-diaminoanthraquinone. These dyes absorb at around 370-490nm. It was found that introduction of naphthalene and anthraquinone moiety on the perinone system produces a large bathochromic shift of 100nm. The synthesized dye 7 containing anthraquinone moiety in perinone chromophoric system exhibited superior heat stability and bright color as yellow chromophore. New dye 7 have been investigated in terms of interacting with volatile organic compound(VOC) $EtNH_2$. The sensing behaviour of the dye 7 toward $EtNH_2$ was studied by UV-vis absorption spectroscopy. Sensing mechanism of dye 7 to $EtNH_2$ was supported by theoretical calculations based on DFT method.

Gas sensing properties of CuO nanowalls synthesized via oxidation of Cu foil in aqueous NH4OH (NH4OH 수용액 하에서 Cu 호일의 산화를 통해 합성한 CuO 나노벽의 가스센싱 특성)

  • ;;;Lee, Si-Hong;Lee, Sang-Uk;Lee, Jun-Hyeong;Kim, Jeong-Ju;Heo, Yeong-U
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2018.06a
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    • pp.141-141
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    • 2018
  • Copper is one of the most abundant metals on earth. Its oxide (CuO) is an intrinsically p-type metal-oxide semiconductor with a bandgap ($E_g$) of 1.2-2.0 eV 1. Copper oxide nanomaterials are considered as promising materials for a wide range of applications e.g., lithium ion batteries, dye-sensitized solar cells, photocatalytic hydrogen production, photodetectors, and biogas sensors 2-7. Recently, high-density and uniform CuO nanostructures have been grown on Cu foils in alkaline solutions 3. In 2011, T. Soejima et al. proposed a facile process for the oxidation synthesis of CuO nanobelt arrays using $NH_3-H_2O_2$ aqueous solution 8. In 2017, G. Kaur et al. synthesized CuO nanostructures by treating Cu foils in $NH_4OH$ at room temperature for different treatment times 9. The surface treatment of Cu in alkaline aqueous solutions is a potential method for the mass fabrication of CuO nanostructures with high uniformity and density. It is interesting to compare the gas sensing properties among CuO nanomaterials synthesized by this approach and by others. Nevertheless, none of above studies investigated the gas sensing properties of as-synthesized CuO nanomaterials. In this study, CuO nanowalls versus nanoparticles were synthesized via the oxidation process of Cu foil in NH4OH solution at $50-70^{\circ}C$. The gas sensing properties of the as-prepared CuO nanoplates were examined with $C_2H_5OH$, $CH_3COCH_3$, and $NH_3$ at $200-360^{\circ}C$.

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Estimation of Precipitable Water from the GMS-5 Split Window Data (GMS-5 Split Window 자료를 이용한 가강수량 산출)

  • 손승희;정효상;김금란;이정환
    • Korean Journal of Remote Sensing
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    • v.14 no.1
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    • pp.53-68
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    • 1998
  • Observation of hydrometeors' behavior in the atmosphere is important to understand weather and climate. By conventional observations, we can get the distribution of water vapor at limited number of points on the earth. In this study, the precipitable water has been estimated from the split window channel data on GMS-5 based upon the technique developed by Chesters et al.(1983). To retrieve the precipitable water, water vapor absorption parameter depending on filter function of sensor has been derived using the regression analysis between the split window channel data and the radiosonde data observed at Osan, Pohang, Kwangiu and Cheju staions for 4 months. The air temperature of 700 hPa from the Global Spectral Model of Korea Meteorological Administration (GSM/KMA) has been used as mean air temperature for single layer radiation model. The retrieved precipitable water for the period from August 1996 through December 1996 are compared to radiosonde data. It is shown that the root mean square differences between radiosonde observations and the GMS-5 retrievals range from 0.65 g/$cm^2$ to 1.09 g/$cm^2$ with correlation coefficient of 0.46 on hourly basis. The monthly distribution of precipitable water from GMS-5 shows almost good representation in large scale. Precipitable water is produced 4 times a day at Korea Meteorological Administration in the form of grid point data with 0.5 degree lat./lon. resolution. The data can be used in the objective analysis for numerical weather prediction and to increase the accuracy of humidity analysis especially under clear sky condition. And also, the data is a useful complement to existing data set for climatological research. But it is necessary to get higher correlation between radiosonde observations and the GMS-5 retrievals for operational applications.