• Title/Summary/Keyword: $CH_4/N_2$

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A Study on the Current Shroud(I) (현행건의에 관한 연구(I))

  • 유관순
    • Journal of the Korean Society of Costume
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    • v.21
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    • pp.49-59
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    • 1993
  • Actual conditions of current shroud are as follows. 1. The kinds of shroud in formal funeral cer-emonies were more variable than infor-mal ceremonies. 2. The cloths of the shround were all Myongchu or all Sambe inside and outside or the inside was Sambe and the outside was Myongchu. The color was light color center upon the white color and black Kongtan was used mostly in Myokmok. 3. Terms of the shroud were different in each region. 4. The kinds of recommended men's shroud were Ch ksam, Ch kori, Naeko, Ko, Torumaki, Topo, Topotae, Mal, Myokmok, Aksu, Ch'im, Ch' nkum, Chiyok, Ryomp'o, Soryomkum, Haengch n, Onang, Tae, Taennim, Pokk n, Kwatu, tec. And the kinds of recommended women's shroud were Ch ksam, Ch kori, Soksokkos, Ko, Tansokkos, Naesang, Oesang, Turumaki, Wonsam, Wonsamtae, Mal, Myokmok, Aksu, Ch'im, Ch' nkum, Chiyok, Ryomp'o, Onang, Soryomkum, Kwatu, etc.

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Unexpected Rate Retardation in the Formation of Phthalic Anhydride from N-Methylphthalamic Acid in Acidic H2O-CH3CN Medium

  • Ariffin, Azhar;Khan, M. Niyaz
    • Bulletin of the Korean Chemical Society
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    • v.26 no.7
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    • pp.1037-1043
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    • 2005
  • Kinetic study on the cleavage of N-methylphthalamic acid (NMPA) in mixed acidic aqueous-acetonitrile solvent reveals the formation of both phthalic anhydride (PAn) (through O-cyclization) and N-methylphthalimide (NMPT) (through N-cyclization). The formation of NMPT varies from $\sim$20% to $\sim$3% with the increase in the content of acetonitrile from 2 to 70% v/v. Pseudo first-order rate constants for the formation of PAn are more than 4-fold larger than those for the formation of NMPT at 2% v/v $CH_3CN$ in mixed aqueous solvents. Pseudo first-order rate constants for alkaline hydrolysis of NMPT reveal a nonlinear decrease with increase in the content of $CH_3CN$ in mixed aqueous solvents.

Intramolecular Ion-Molecule Reactions within Ti+(CH3COCH3)n Heteroclusters: Oxidation Pathway via C=O Bond Activation

  • Koo, Young-Mi;Hong, Ki-Ryong;Kim, Tae-Kyu;Jung, Kwang-Woo
    • Bulletin of the Korean Chemical Society
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    • v.31 no.4
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    • pp.953-958
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    • 2010
  • A laser ablation-molecular beam/reflectron time-of-flight mass spectrometric technique was used to investigate the ion-molecule reactions that proceed within $Ti^+(CH_3COCH_3)_n$ heterocluster ions. The reactions of $Ti^+$ with $CH_3COCH_3$ clusters were found to be dominated exclusively by an oxidation reaction, which produced $TiO^+(CH_3COCH_3)_n$ clusters. These ions were attributed to the insertion of a $Ti^+$ ion into the C=O bond of the acetone molecule within the heteroclusters, followed by $C_3H_6$ elimination. The mass spectra also indicated the formation of minor sequences of heterocluster ions with the formulas $Ti^+(C_3H_4O)(CH_3COCH_3)_n$ and $TiO^+(OH)(CH_3COCH_3)_n$, which could be attributed to C-H bond insertion followed by $H_2$ elimination and to the sequential OH abstraction by the $TiO^+$ ion, respectively. Density functional theory calculations were carried out to model the structures and binding energies of both the association complexes and the relevant reaction products. The reaction pathways and energetics of the $TiO^+\;+\;CH_2CHCH_3$ product channel are presented.

Resolution of Tocainide and Its Analogues on a Doubly Tethered N-CH3 Amide Chiral Stationary Phase Based on (+)-(18-Crown-6)-2,3,11,12-tetracarboxylic Acid

  • Lee, Kyu Jung;Tak, Kyung Mi;Hyun, Myung Ho
    • Bulletin of the Korean Chemical Society
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    • v.34 no.10
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    • pp.2978-2982
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    • 2013
  • A doubly tethered $N-CH_3$ amide chiral stationary phase (CSP 4) based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid was applied to the resolution of an antiarrythmic agent, tocainide, and its analogues and the chromatographic resolution results were compared with those on a singly tethered N-H amide CSP (CSP 1), a singly tethered $N-CH_3$ amide CSP (CSP 2) and a doubly tethered N-H amide CSP (CSP 3) under an identical aqueous mobile phase condition. CSP 4 was found to be generally better than other CSPs in terms of the separation factors (${\alpha}$) and resolutions (RS). The retention times of analytes denoted by the retention factors ($k_1$) on CSP 4 were quite long compared to those on other CSPs because of the improved lipophilicity of CSP 4. The long retention times of analytes on CSP 4 were successfully controlled by the addition of a small amount of ammonium acetate to aqueous mobile phase without hurting the chiral recognition efficiency. The variation of the content and type of organic and acidic modifier in aqueous mobile phase was found not to change the chiral recognition efficiency significantly.

Proton Transfer Reactions and Ion-Molecule Reactions of Ionized XCH2CH2Y (X and Y = OH or NH2)

  • Choi, Sung-Seen;So, Hun-Young
    • Bulletin of the Korean Chemical Society
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    • v.27 no.4
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    • pp.539-544
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    • 2006
  • Proton transfer reactions and ion-molecule reactions of bifunctional ethanes of $H_2NCH_2CH_2NH_2$, $H_2NCH_2CH_2OH$, and $HOCH_2CH_2OH$ were studied using Fourier transform mass spectrometry (FTMS). The rate constants for proton transfer reactions between the fragment ions and neutral molecules were obtained from the temporal variation of the ion abundances. The rate constants were consistent with the heats of reaction. The fastest proton transfer reactions were the reactions of $CH_2N^+$, $CHO^+$, and $CH_3O^+$ for $H_2NCH_2CH_2NH_2$, $H_2NCH_2CH_2OH$, and $HOCH_2CH_2OH$, respectively. The $[M+13]^+$ ion was formed by the ion-molecule reaction between $H_2C=NH_2 ^+$ or $H_2C=OH^+$ and the neutral molecule. The major product ions generated from the ion-molecule reactions between the protonated molecule and neutral molecule were $[2M+H]^+$, $[M+27]^+$, and $[M+15]^+$.

The Chemical Constituents of the Stem Barks of Fraxinus rhynchophylla (물푸레나무(Fraxinus rhynchophylla) 수피의 추출성분)

  • Yang, Eun-Ju;Lee, Dong-Geun;Lee, Jong-Won;Kim, Yae-Sil;Lim, Sun-Ha;Song, Kyung-Sik
    • Applied Biological Chemistry
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    • v.50 no.4
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    • pp.348-351
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    • 2007
  • The stem barks of Fraxinus rhynchophylla was extracted with 95% EtOH, and the concentrated extract was successively partitioned with $CH_2Cl_2$, n-BuOH, and $H_2O$ in order to investigate the major phytochemicals. From the $CH_2Cl_2$ soluble fraction, a sterol (1) was isolated through the repeated silica gel column chromatographies. Three additional compounds (2-4) were isolated from the n-BuOH soluble fraction through silica gel, RP-18, and Sephadex LH-20 column chromatographies. Their chemical structures were elucidated as daucosterol $(1;{\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside)$, caffeic acid (2), 6,8-dihydroxy-7-methoxycoumarin (3), and coniferaldehyde glucoside (4) by comparing their spectral data with those in the literatures. All isolates (1-4) were the first to be isolated from F. rhynchophylla.

Evaluation of Green House Gases Emissions According to Changes of Soil Water Content, Soil Temperature and Mineral N with Different Soil Texture in Pepper Cultivation (고추재배에서 토성별 토양수분, 토양온도, 무기태 질소 변화에 따른 온실가스배출 평가)

  • Kim, Gun-Yeob;Song, Beom-Heon;Roh, Kee-An;Hong, Suk-Young;Ko, Byung-Gu;Shim, Kyo-Moon;So, Kyu-ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.41 no.6
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    • pp.399-407
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    • 2008
  • Importance of climate change and its impact on agriculture and environment has increased with a rise of greenhouse gases (GHGs) concentration in Earth's atmosphere, which had caused an increase of temperature in Earth. Greenhouse gas emissions such as methane($CH_4$) and nitrous oxide($N_2O$) in the field need to be assessed. GHGs fluxes using chamber systems in the fields(2004~2005) with pepper cultivation were monitored at the experimental plots of National Academy of Agricultural Science(NAAS), Rural Development Administration(RDA) located in Suwon city. $N_2O$ emission during pepper growing period was reduced to 74.0~82.1% in sandy loam soil compared with those in clay loam soil. Evaluating $N_2O$ emission at different levels of soil water conditions, $N_2O$ emission at -50 kPa were lowered to 13.2% in clay loam soil and 40.2% in sandy loam soil compared with those at -30 kPa. $CH_4$ emission was reduced to 45.7~61.6% in sandy loam soil compared with those in clay loam soil. Evaluating $CH_4$ at different levels of soil water conditions, $CH_4$ emission at -50 kPa was lowered to 69.6% in clay loam soil and 55.8% in sandy loam soil compared with those at -30 kPa. It implied that -50 kPa of soil water potential was effective for saving water and reducing GHG emissions. From the path analysis as to contribution factors for $N_2O$ emission, it appeared that contribution rate was in the order of mineral N(51.2%), soil temperature (25.8%), and soil moisture content(23.0%) in clay loam soil and soil moisture content(39.3%), soil temperature (36.4%), and mineral N(24.3%) in sandy loam soil.

Effects of $CO_2$ and $O_2$ Addition on Methane Dry Reforming Using Arc-Jet Plasma Reactor (아크제트 플라즈마를 이용한 메탄건식개질 반응에서 $CO_2$$O_2$ 첨가의 영향)

  • Hwang, N.K.;Cha, M.S.;Song, Y.H.
    • Journal of the Korean Society of Combustion
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    • v.13 no.4
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    • pp.47-53
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    • 2008
  • The reaction mechanism of methane dry reforming has been investigated using an arc-jet reactor. The effects of input power, $CO_2/CH_4$ and added $O_2$ were investigated by product analysis, including CO, $H_2$, $C_{2}H_{Y}$ and $C_{3}H_{Y}$ as well as $CH_4$ and $CO_2$. In the process, input electrical power activated the reactions between $CH_4$ and $CO_2$ significantly. The increased feed ratio of the $CO_2$ to $CH_4$ in the dry reforming does not affect to the $CH_4$ conversion. but we could observe increase in CO selectivity together with decreasing $H_2$ generation. Added oxygen can also increase not only CO selectivity but also $CH_4$ conversion. However, hydrogen selectivity was decreased significantly due to a increased $H_{2}O$ formation.

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Emission of Greenhouse Gases from Upland Rice and Soybean (밭벼와 콩 재배지의 온실가스 배출)

  • Shin, Yong-Kwang;Ahn, Jong-Woong;Koh, Mun-Hwan;Shim, Jae-Chun
    • Korean Journal of Soil Science and Fertilizer
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    • v.36 no.4
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    • pp.256-262
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    • 2003
  • The emission of methane and nitrous oxide was measured from fields of upland rice and soybean. Rice cultivar, Daejinbyeo, was seeded in a row of 30 cm space in upland soil on April 28, 2001. The fields were irrigated with sprinkler irrigation or natural precipitation. Three soybean cultivars Jangyeobkong, Taekwangkong and Hwangkeumkong, were sown with seeding space of $60{\times}15cm$ on June 16, 2001. Gas samples were collected twice a week during the growth period, and methane and nitrous oxide were analyzed. Methane emission from upland rice field of sprinkler irrigation was $3.5kg\;CH_4\;ha^{-1}$. However, negative emission of methane, $-1.7kg\;CH_4\;ha^{-1}$, was observed in upland rice field of natural precipitation. Total nitrous oxide emission from upland rice field of sprinkler irrigation was $50.8kg\;N_2O\;ha^{-1}$, while the emission in the field of natural precipitation was $8.3kg\;N_2O\;ha^{-1}$. Global warming potentials (GWP) in the upland rice fields of sprinkler irrigation and natural precipitation were 15,822 and $2,216kg\;CO_2\;ha^{-1}$, respectively. Methane emissions from fields of soybean cultivars Jangyeobkong, Taekwangkong and Hwangkeumkong were -14.7, -4.3 and $4.8kg\;CH_4\;ha^{-1}$, respectively. Total nitrous oxide emissions from fields of soybean cultivars Jangyeobkong, Taekwangkong and Hwangkeumkong were 4.7, 4.6 and $3.0kg\;N_2O\;ha^{-1}$, respectively. Total GWPs for soybean cultivars Jangyeobkong, Taekwangkong and Hwangkeumkong were 1152, 1323 and $1027kg\;CO_2\;ha^{-1}$, respectively.

Separation of Gas Based on PTMSP-silica-PEI Composites (PTMSP-silica-PEI 복합막에 의한 기체 분리에 관한 연구)

  • Kang Tae-Bum;Hong Se-Lyung
    • Membrane Journal
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    • v.16 no.2
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    • pp.123-132
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    • 2006
  • The PTMSP-silica-PEI composite membranes were synthesized from tetraethoxysilane (TEOS) and poly (1-trimethylsilyl-1-propyne) (PTMSP) by sol-gel process. The PTMSP-silica nanocomposite membranes were characterized by $^1H-NMR$, FT-IR, TGA, XPS, SEM, GPC and gas permeation measurements were accomplished with $H_2,\;O_2,\;N_2,\;CO_2,\;CH_4$. The gases permeability increased with increasing TEOS content. Both the permeability and selectivity of $H_2,\;CH_4$ increased to 15 wt% TEOS. While the permeability of $O_2,\;CO_2$ increased without decrease of selectivity.