• Title/Summary/Keyword: methane detection

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Effect of substrate bias voltage on a-C:H film (기판 bias 전압이 a-C:H 박막의 특성에 미치는 영향)

  • 유영조;김효근;장홍규;오재석;김근식
    • Journal of the Korean Vacuum Society
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    • v.6 no.4
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    • pp.348-353
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    • 1997
  • Hydrogenated amorphous carbon(a-C:H) films were deposited on p-type Si(100) by DC saddle-field plasma enhanced CVD to investigate the effect of substrate bias on optical properties and structural changes. They were deposited using pure methane gas at a wide range of substrate bias at room temperature and 90 mtorr. The substrate bias voltage ($V_s$) was employed from $V_s=0 V$ to $V_s=400 V$. The information of optical properties was investigated by photoluminescence and transmitance. Chemical bondings of a-C:H have been explored from FT-IR and Raman spectroscopy. The thickness and relative hydrogen content of the films were measured by Rutherford backscattering spectroscopy (RBS) and elastic recoil detection (ERD) technigue. The growth rate of a-C:H film was decreased with the increase of $V_s$, but the hydrogen content of the film was increased with the increase of $V_s$. The a-C:H films deposited at the lowest $V_s$ contain the smallest amount of hydrogen with most of C-H bonds in the of $CH_2$ configuration, whereas the films produced at higher $V_s$ reveal dominant the $CH_3$ bonding structure. The emission of white photoluminescence from the films were observed even with naked eyes at room temperature and the PL intensity of the film has the maximum value at $V_s$=200 V. With $V_s$ lower than 200 V, the PL intensity of the film increased with V, but for V, higher than 200 V, the PL intensity decreased with the increase of $V_s$. The peak energy of the PL spectra slightly shifted to the higher energy with the increase of $V_s$. The optical bandgap of the film, determined by optical transmittance, was increased from 1.5 eV at $V_s$=0V to 2.3 eV at $V_s$=400 V. But there were no obvious relations between the PL peak and the optical gap which were measured by Tauc process.

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A Study on the Water Quality of Reservoir Tank in the Building Complex on Jeonnam Area (대형건축물 저수조의 수질실태 및 개선방안에 관한 연구)

  • Lee, J.H.;Lee, H.H.;Kim, H.B.;Ahn, G.W.;Park, K.N.;Kim, Y.K.;Bae, J.S.;Mun, H.;Park, C.U.;Oh, E.H.;Park, S.I.;Seo, Y.G.
    • Journal of environmental and Sanitary engineering
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    • v.15 no.4
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    • pp.59-77
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    • 2000
  • This study was carried out to investigate on several factors, which contaminative the water quality through the water pipe during feeding water, in 42 largescaled apart-ments(total 84 cases) and assayed the Volatile Organic Compounds(VOCs) and concen-tration of heavy metals that inflow and outflow in reservior water in Jeonnam area(Mokpo, Suncheon, Yeosu) from January 1999 to December 1999. The results obtained were summarized as follows ; 1. The quality of the water pipe composition in the order of frequency in the quality of water pipes were Copper(45.2%)> Zinc(38.9%)> Stainless steel(9.5%)> PVC(4.8%)> PM(2.4%) in observing 42 sites. All of the drain pipes were used the cast iron quality. 2. The result of certification curve from 12 items(17kind) of VOCs was $1.0-4.0{\mu{g}}/{\ell}$ range, a coefficient of correlation was shown 0.99 over. A MDL of each substance range was within $0.1-1.0{\mu{g}}/{\ell}$. 3. The result of the assay, 5 kinds(Viny chloride, Dichloromethane, Ethylbenzene, M,P-xylene, Styrene) of the VOCs of 14 kinds was not detected and the other items were detected slightly. The detection rate of one item and over in total VOCs samples, were 25.9% in inflow and 27.9% in outflow. And frequency of detect in inflow/outflow of THM(Chloroform, Bromodichloro-methane, Dibromochloromethane, Bromoform) were shown higher than 94.1%, 97.0% each stages. It comes to the conclusion that all of the samples were reason able for drinking water standards. 4. The coefficient of correlation were reasonable, it shown 0.999 over in $0.1-1.0{\mu{g}}/{\ell}$ of a measuring range conditions of 4kinds in organic substance(Zn, Cu, Fe, Mn). 5. The results were showed suitability in 78 cases(92.9%) and unsuitability in 6 cases (7.1%), in 84 cases of in organic substances. Compare to inflow stage, mean concentrations of heavy metal, were increased slightly in Zn, Cu, Fe except Mn than outflow stage. The result of the mean concentration in organic substance inflow and outflow in the apartment water tank using Pair-compared T-test, in 95% reliance index, were $0.179mg/{\ell}(0.151-0.307mg/{\ell})$ in Zinc, $0.136mg/{\ell}(0.113-0.230mg/{\ell})$ in Copper, $0.052mg/{\ell}(0.048-0.098mg/{\ell})$ in Fe, and there was a bit growing tendency but there was no differece in Mn. 6. The mean concentration of Copper which used Cu pipe as a water supply pipe in apartment were $0.216mg/{\ell}(0.161-0.338mg/{\ell})$ in case of the Zine pipe were $0.286mg/{\ell}(0.204-0.435mg/{\ell})$. It shows that the detection rate was more higher than the other material used in Cu or Zn as the water supply pipe. We supposed to Cu and Zn substance were gushing out water supply pipe.

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Anti-oxidative and Anti-inflammatory Activities of Fermented Turmeric (Curcuma longa L.) by Rhizopus oryzae (Rhizopus oryzae으로 발효한 울금의 항산화 및 항염효과)

  • Kim, Eun-Ju;Song, Bit-Na;Jeong, Da-Som;Kim, So-Young;Cho, Yong-Sik;Park, Shin-Young
    • Journal of Life Science
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    • v.27 no.11
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    • pp.1315-1323
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    • 2017
  • Turmeric is a rhizomatous herbaceous perennial plant (Curcuma longa (CL)) of the ginger family, Zingiberaceae. A yellow-pigmented fraction isolated from the rhizomes of CL contains curcuminoids belonging to the dicinnamoyl methane group. Curcumin is an important active ingredient responsible for the biological activity of CL. However, CL is not usually used as a food source due to its bitter taste. The present study was designed to determine the effect of the CL fermented by Rhizopus oryzae (FCL) on pro-inflammatory factors such as nuclear factor ${\kappa}B$ ($NF-{\kappa}B$), tumor necrosis factor alpha ($TNF-{\alpha}$), interleukin-6 (IL-6), nitric oxide (NO), prostaglandin $E_2$ ($PGE_2$), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-induced RAW 264.7 cell line. The cell viability was determined by MTT assay. To evaluate the anti-inflammatory effect of FCL 80% EtOH extracts, IL-6 and $TNF-{\alpha}$ were measured by ELISA kit. Also, the amount of $NO/PGE_2/NF-{\kappa}B$ was measured using the $NO/PGE_2/NF-{\kappa}B$ detection kit and the iNOS/COX-2 expression was measured by Western blotting. The results showed that the FCL reduced NO, $PGE_2$, iNOS, COX-2, $NF-{\kappa}B$, IL-6 and $TNF-{\alpha}$ production without cytotoxicity. These results suggest that FCL extracts may be a developed the functional food related to anti-inflammation due to the significant effects on inflammatory factors.