• Microbiology and Biotechnology Letters
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• v.45 no.4
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• pp.322-329
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• 2017

Two pilot-scale biocovers (PBCs) were installed in a landfill, and the methane ($CH_4$) concentrations at their inlets and outlets were monitored for 240 days to evaluate the methane removability. Consequently, the packing materials were sampled from the PBCs, and their potential $CH_4$ oxidizing abilities were evaluated in serum vials. The $CH_4$ concentration at the inlet of the biocovers was observed to be in the range of 23.7-47.9% (average = 41.3%, median = 42.6%). In PBC1, where a mixture of soil, earthworm cast, and compost (7:2:1, v/v) was employed as the packing material, the $CH_4$ removal efficiency was evaluated to be between 60.7-85.5%. In PBC2, which was filled with a mixture of soil, earthworm cast, perlite, and compost (4:2:3:1, v/v), the removal efficiency was evaluated to be between 29.2-78.5%. Although the packing materials had an excellent $CH_4$ oxidizing potential (average oxidation rate for $CH_4=180-199{\mu}g\;CH_4{\cdot}g\;packing\;material^{-1}{\cdot}h^{-1}$), $CH_4$ removal efficiency in PBC1 and PBC2 decreased to the range of 0-30% once the packing materials in the PBCs were clogged and channeled. Furthermore, seasonal effects exhibited no significant differences in the $CH_4$ removal efficiency of the biocovers. The results of this study can be used to design and operate real-scale biocovers in landfills to mitigate $CH_4$ buildup.

• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.3873-3879
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• 2011

The potential energy surface (PES) for the isomerizations and dissociations of the acrylonitrile radical cation was determined from the CBS-QB3 and CBS-APNO calculations. The Rice-Ramsperger-Kassel-Marcus model calculations were performed based on the PES in order to predict the competitions among the dissociation channels. The mechanisms for the loss of $H^{\bullet}$, $H_2$, $CN^{\bullet}$, HCN, and HNC were proposed. The $C_3H_2N^+$ ion formed by loss of $H^{\bullet}$ was predicted as a mixture of $CH{\equiv}C-C=NH^+$, $CH{\equiv}C-N{\equiv}CH^+$, and $CH_2=C-C{\equiv}N^+$. Furthermore $CH{\equiv}C-C{\equiv}N^{+{\bullet}}$ was formed mainly by a consecutive 1,2-H shift and 1,2-H2 elimination.

• Journal of the Korean Vacuum Society
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• v.3 no.1
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• pp.122-129
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• 1994

MWPECVD법으로 CH3CHO-H2 계와 CH4-H2-O2 계로부터 Si 기판 위에 다이아몬드박막을 성장 시키고 성장된 박막을 SEM XRD 및 Raman 분광기로 평가하고 박막과 입자의 성장률을 조사하였다. 마이크로 판전력 950W 반응관압력 80torr 수소유량 200sccm 기판온도 95$0^{\circ}C$ 및 CH3CHO농도 3.5%로 5시간 성장시킨 다이아몬드의 박막성장율은 $4mu$m/hr가 되어고 12%$960^{\circ}C$로 Si기판 위에 5시간 성장시킨 다이아몬드의 박막성장율은 3.2$\mu$m/hr가 되었다.

• Journal of Animal Environmental Science
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• v.13 no.1
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• pp.1-12
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• 2007

Stored animal manure is considered as a significant agricultural source of methane $(CH_4)$ and nitrous oxide $(N_2O)$ which have 23 and 297 times higher global warming effect when compared to carbon dioxide $(CO_2)$. Uncertainties caused by lack of understanding physical and biochemical environment in stored animal manure and by errors of emission measurement methods, even though many researches measuring $CH_4\;and\;N_2O$ emissions from stored manure have been conducted for a few decades. In this paper, general information of $CH_4\;and\;N_2O$ generation and emissions from stored animal manure and the measurement methods for quantifying $CH_4\;and\;N_2O$ emissions are discussed.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.4
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• pp.166-171
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• 2006

[ $Cu_2O$ ] and Cu have been synthesized from the layered organic-inorganic hybrid, $Cu_2(OH)_3(CH_3COO){\cdot}H_2O$, assisted by microwave irradiation. $Cu_2O$ is formed in aqueous glucose solution, while metallic Cu is formed in ethylene glycol by reduction of $Cu_2(OH)_3(CH_3COO){\cdot}H_2O$. The influence of microwave irradiation time and concentration of glucose on $Cu_2O$ particles formation and growth has been examined. The morphologies of $Cu_2O$ particles change from spheres with a few fm size to nanowires with diameter of 40 nm as increasing the microwave irradiation times.

• Journal of the Korean Magnetics Society
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• v.6 no.3
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• pp.151-157
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• 1996

Magnetic properties and microstructures of FeTaNC thin films, which were deposited by magnetron reactive sputtering rrethod, were investigated as a function of $CH_{4}$ and $N_{2}$ gas partial pressures. Magnetic properties of FeTaNC films depended on total reactive gas pressure as well as $CH_{4}/N_{2}$ pressure ratios. For reactive gas partial pressures of 5~10 %, optimum magnetic properties were observed in the FeTaNC films with proper $CH_{4}/N_{2}$ ratio. On the other hand, at 15% of gas partial pressure, FeTaN and FeTaC films showed superior properties to FeTaNC films. Above 15%, the magnetic properties of films rapidly degraded due to an excess incorporation of C and/or N atoms. Excellent soft magnetic properties of 17 kG of Bs, 0.3 Oe of He, and 4000 of $\mu'$(at 5 MHz) were obtained in the FeTaNC films. High permeabilities of FeTaNC films could be explained by the Fe lattice distortion caused by N atoms, hence reduction of magnetic anisotopy. While precipitated TaN and TaC particles effectively supress the growth of $\alpha-Fe$ grains leading to a good soft magentic properties, FeN and FeC phases such as $Fe_3N$, $Fe_4N$, FexC have detrimental effects.

• Journal of the Korean Chemical Society
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• v.24 no.1
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• pp.1-7
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• 1980

Solvolysis rate constants for methylchloroformate, methylthionochloroformate, methylthiolchloroformate and methyldithiochloroformate have been determined conductometrically in methanol, ethanol and ethanol-water mixtures and activation parameters have been derived. Results show that methylchloroformate solvolyzes through $S_N2$ process while methyldithiochloroformate solvolyzes by $S_N1$ process in all the solvent systems. The rate of hydrolysis decreased in the order, $CH_3S(CS)Cl>CH_3S(CO)Cl>CH_3O(CS)Cl>CH_3O(CO)Cl$ which corresponds to the order of decreasing $S_N1$ character. In methanol, $CH_3S(CS)Cl$ solvolyzed via the $S_N1$ mechanism while the others solvolyzed via the $S_N2$ process. In ethanol, however, $S_N2$ character was dominant for all the compounds, except methyldithiochloroformate, for which $S_N1$ character was still strong enough to accelerate the rate of ethanolysis. In ethanol-water mixtures, $CH_3S(CS)Cl$ and $CH_3S(CS)Cl$ solvolyzed via $S_N2$ process in ethanol-rich region while the $S_N1$ character increased greatly in water-rich region for the solvolysis of these compounds. The order of $S_N1$ character for solvolysis in water-rich region was the same as the order of hydrolysis rate.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.3
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• pp.212-219
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• 2000

This study was conducted to investigate methane emission among nitrogen fertilizers in paddy soil(Jeonbug series, occurring on fluvio-alluvial plain). The application rates of rice straw was $5,000kg\;ha^{-1}$ with $110kg\;N\;ha^{-1}$ as chemical fertilizer. It was found that the methane flux tended to be lower in ammonium sulfate than in urea and latex coated urea(LCU). The seasonal variations of the methane emission flux was high during the heading stage of the rice plant. Methane concentration in the soil solution was the highest at 5cm depth, but decreased with upper and lower depth. Methane emission under rice straw application was $0.265g\;m^{-2}\;day^{-1}$ by urea application. $0.207g\;m^{-2}\;day^{-1}$ by ammonium sulfate application, $0.318g\;m^{-2}\;day^{-1}$ by latex coated urea(LCU) application while methane emission under non rice straw application was $0.192g\;m^{-2}\;day^{-1}$ by urea application, $0.165g\;m^{-2}\;day^{-1}$ by ammonium sulfate application, $0.179g\;m^{-2}\;day^{-1}$ by latex coated urea(LCU) application.

• Journal of Nutrition and Health
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• v.56 no.2
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• pp.123-139
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• 2023

Purpose: This study was conducted to establish whether an ethanol extract of Lycium barbarum leaves (LLE) and an ethanol extract of Lycium barbarum leaves from which chlorophyll has been removed, denoted as LLE(Ch^-), have a protective effect against hepatic fat accumulation. Methods: The inhibitory effects of LLE and LLE(Ch^-) on liver fat accumulation were examined in C57BL/6 mice with non-alcoholic fatty liver disease (NAFLD) induced by an methionine and choline deficient diet and in HepG2 cells with palmitic acid-induced fat accumulation. Results: The plasma triglyceride, aspartate aminotransferase, and alanine aminotransferase levels were lower in the LLE(Ch^-) group, whereas the plasma ALT activity decreased significantly in the LLE group. In both the LLE and the LLE(Ch^-) groups, the triglyceride and cholesterol contents in the hepatic tissue were significantly reduced. A greater inhibitory effect on tissue fat accumulation was observed in the LLE(Ch^-) group than in the LLE group. In HepG2 cells, LLE and LLE(Ch^-) were non-toxic up to a concentration of 1,000 ㎍/mL. Compared to the control group, intracellular fat accumulation in the LLE and LLE(Ch^-) groups were significantly reduced at concentrations of 200 ㎍/mL and 500 ㎍/mL, respectively. The expression of phosphorylated adenosine monophosphate-activated protein kinase and phosphorylated acetyl-CoA carboxylase in both LLE groups increased at the concentrations of 100 ㎍/mL and 500 ㎍/mL. The fatty acid synthase expression was suppressed in a concentration-dependent manner at 10 ㎍/mL. Conclusion: The examined two ethanol extracts of LLE inhibit hepatic fat accumulation in NAFLD. This effect was more pronounced in the LLE(Ch^-) group. Therefore, these 2 extracts have an anti-steatosis effect and can be used for NAFLD treatment.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.445-448
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• 2002

New banana-shaped achiral compounds, 1,3-phenylene bis [4-{4-(7-octenyloxy)phenyliminomethyl}benzoate](PBOEB), 1,3-phenylene bis [4-{3-fluoro-4-(7-octenyloxy)phenyliminomethyl}benzoate] (PBFOEB), 1,3-phenylene bis [4-{4-(10-undecyloxy)phenyliminomethyl}benzoate](PBEUB), and 1,3phenylene bis [4-{3-fluoro-4-(10-undecyloxy)phenyliminomethyl}benzoate](PBFEUB) were obtained by general synthetic methods. PBOEB and PBFOEB having the octenyloxy groups such as $-(CH_2)_6CH=CH_2$ showed ferroelectric switching, and their values of spontaneous polarization on reversal of an applied electric field were 120 nC/$cm^2$ and 225 nC/$cm^2$, respectively. PBEUB and PBFEUB having the undecyloxy groups such as $-{CH_2)_9CH=CH_2$ showed antiferroelectric switching, and their values of spontaneous polarization on reversal of an applied electric field were 120 nC/$cm^2$ and 140 nC/$cm^2$, respectively. We could obtain ferroelectric and antiferroelectric phases by controlling the number of carbon atom in alkenyloxy chains of bent-core molecules.