• 제목/요약/키워드: Ammonia solution

검색결과 366건 처리시간 0.031초

백부자 Aconiti koreani Rhizoma의 성분연구 (The Studies on the Constituents of Baek-bu-ja, Aconiti koreani Rhizoma)

  • 한대석;김정연
    • 생약학회지
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    • 제2권1호
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    • pp.39-40
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    • 1971
  • An alkaloidal component was extracted from the root of Aconitum koreanum R. $R_{AYMOND}$ of the commercial origin. Crude extract was obtained in ca. 2% yield out of dried root with ether-methanol (10:1). White amorphous compound was precipitated out from the HCl solution upon the addition of ammonia water, and crude base was obtained by extraction of its mother liquid with chloroform. This crude base was purified by the alumina-column chromatographic method. A pure alkaloidal component(500mg) was yielded from its crude base. Its pure base comes as needle crystals melting at $250{\sim}252^{\circ}C$ (decomp.), $[\alpha]^{20}_D$ D+9.82 (methanol) and Anal. calcd. for $C_{19}H_{27}O_{8}N$.

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암모니아 공정에서 탄산칼륨용액 흡수에 의한 $CO_2$ 고정화 (Fixation of $CO_2$ in Ammonia Process by Potassium Carbonate Solution Absorption)

  • 이정섭;송준석;윤형선;서성규
    • 한국대기환경학회:학술대회논문집
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    • 한국대기환경학회 2003년도 추계학술대회 논문집
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    • pp.485-486
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    • 2003
  • 산업사회의 발전과 문화생활의 향상에 따라 에너지 사용은 계속 증가해 왔으며, 이에 따른 환경문제 또한 꾸준히 제기되고 있다 산업구조상 화석연료를 주 에너지원으로 사용하고 있는 우리나라의 경우 온실 가스중 $CO_2$가 87.7%를 차지한다. 또한 이 $CO_2$가 대기 중에서 10.0%가 초과되면 인체에 심각한 신진대사의 이상, 중앙신경계의 장애가 발생할 수 도 있다(환경부, 2000). 에너지 경제연구원은 "2010년까지 2000년 수준으로 $CO_2$ 배출량을 줄이면서 국내 총생산은 17.5% 감소할 전망"이라고 분석했다(에너지 관리공단, 2003). (중략)

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암모니아와 요소용액을 이용한 배출가스내 질소산화물 저감 비교 평가 (NOx Reduction in Flue Gas Using Ammonia and Urea solution)

  • 임영일;이정빈;유경선;김상돈
    • 한국에너지공학회:학술대회논문집
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    • 한국에너지공학회 1995년도 춘계학술발표회 초록집
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    • pp.236-239
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    • 1995
  • 50 kW$_{th}$ 용량의 기체연료버너에서 암모니아 기체와 요소용액을 이용한 선택적 무촉매 환원법 (SNCR;Selective Non-catalytic Reduction) 으로 질소산화물 (NOx) 저감에 관하여 연구하였다. 암모니아는 요소요액보다 더 낮은 반응온도에서 더 높은 효율을 보여주지만 경제성과 암모니아의 부식성 및 맹독성으로 인하여 취급하기에 곤란한 점이 있다. 반면에 요소용액은 적절한 액상첨가제와 기상첨가제를 사용하여 넓은 반응온도범위에서 높은 효율을 얻을 수 있으며 공정상의 조업비를 절감할 수 있다. 본 실험에서는 액상 첨가제인 $CH_3$OH 와 $C_2$H$_{5}$OH 을 사용하여 5$0^{\circ}C$ 정도의 최적반응온도 감소를 얻었으며 LPG 와 합성가스(CH$_4$:CO:H$_2$:$CO_2$=1:4:4:2) 틀 기상 첨가제로 사용하여 높은 질소산화물 저감 효율을 관찰하였다.

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CORRELATION BETWEEN THE TENSILE STRENGTH AND CORROSION BEHAVIOR OF HEAT TREATED ZR-1.0NB ALLOY

  • Kim, Tae-Kyu;Choi, Pyung-Sik;Yang, Sung-Ki;Lee, Chong-Tak;Sohn, Dong-Seong
    • Nuclear Engineering and Technology
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    • 제40권6호
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    • pp.505-510
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    • 2008
  • The correlation between the tensile strength and corrosion behavior of Zr-1.0wt%Nb alloy heat treated at $480^{\circ}C$ for up to 32 hours was evaluated. The tensile strength at $400^{\circ}C$ was continuously reduced with an increasing heat treatment time, mainly due to a grain growth and a decreased area fraction of the precipitates. However, the corrosion resistance in an aqueous ammonia solution at $360^{\circ}C$ was enhanced, mainly due to the formation of $\beta$-Nb precipitates. It is thus concluded that a longer heat treatment time provides a better corrosion resistance while degrading the tensile strength.

1N-알킬-2-아미노-3-에톡시카르보닐-피리디노 [2,3-f]인돌-4,9-디온 유도체의 합성 (I) (Synthesis of 1N-alkyl-2-amino-3-ethoxycarbonyl-pyridino [2,3-f]indole-4,9-dione derivatives (I))

  • 서명은;신성희
    • 약학회지
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    • 제41권5호
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    • pp.575-581
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    • 1997
  • The 6,7-dichlorquinoline-5,8-dione was reacted with ${alpha}$-cyanoacetic acid ethyl ester in ammonia solution to yield 6-(${alpha}$-cyano-${alpha}$-ethoxycarbonyhnethyl)-7-chloroquinoline- 5,8-dione (compound I). When this compound was reacted with some alkyl amines (methylamine, ethylamine, isopropylamine, etc) 2-amino-3-ethoxycarbonyl-N-alkyl-pyridino[2,3-f]indole-4,9-diones (compounds II a-e) were obtained.

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Fabrication of Biomimetic Superhydrophobic and Transparent ZnO Nanorod Arrays

  • 이정한;곽근재;용기중
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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    • pp.380-380
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    • 2011
  • ZnO nanorod (NR) arrays prepared via simple ammonia hydrothermal method exhibiting superhydrophilicity, high transmittance and antireflection. These properties result from the unique surface structure and material property of ZnO NR arrays. Highly rough surface due to ZnO NRs enhanced hydrophobicity/hydrophilicity of the films and short NRs (about 300 nm) made ZnO arrays transparent. ZnO NR films were chemically modified by dipping the sample into 5mM stearic acid/ethanol solution for 3 hours. Then the ZnO NRs became superhydrophobic surfaces, whose contact angle reached 159.2$^{\circ}$ maintaining their high transmittance. These biomimetic ZnO NR arrays can be used in diverse field, such as antifogging/self-cleaning surfaces and optical devices.

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음이온교환수지에 의한 모나자이트중 희토류원소의 분리 (Separation of Rare Earth Elements in Monazite Sand by Anion Exchange Resin)

  • 차기원;이종해;하영구
    • 대한화학회지
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    • 제24권3호
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    • pp.239-244
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    • 1980
  • 모나자이트 중의 Y, La, Ce, Pr 및 Nd 들을 pH 8.4에서 EDTA와 착염을 만들어 미리 음이온 교환수지에 EDTA를 흡착시킨 수지관에 용리시켜 희토류 원소들의 분리를 시도하였다. 용리액은 pH 8.4의 EDTA를 사용하였으며, 용리액의 분율에 따라 측정한 각이온의 분리도는 55∼98%이었다.

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Visible-photoresponsive Nitrogen-Doped Mesoporous TiO2 Films for Photoelectrochemical Cells

  • Bae, Jae-Young;Yun, Tae-Kwan;Ahn, Kwang-Soon;Kim, Jae-Hong
    • Bulletin of the Korean Chemical Society
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    • 제31권4호
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    • pp.925-928
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    • 2010
  • Nitrogen-doped $TiO_2$ ($TiO_2$:N) nano-particles with a pure anatase crystalline structure were successfully synthesized through the hydrolysis of $TiCl_4$ in an ammonia aqueous solution. The samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), $N_2$-sorption, and UV-vis diffuse reflectance spectra (UV-vis DRS) techniques. The absorption edge of nitrogen-doped $TiO_2$ shifted into the visible wavelength region. The photoelectrochemical (PEC) performances were investigated for the $TiO_2$ mesoporous electrodes doped with different nitrogen concentrations. The $TiO_2$:N electrodes exhibited much higher PEC responses compared to the pure $TiO_2$ electrode because of the significantly enhanced visible-photoresponsibility of the $TiO_2$:N electrodes.

습식제련공정에 의한 석유화학 폐촉매로부터 니켈의 회수 (Recovery of Nickel from Spent Petroleum Catalyst by Hydrometallurgical Process)

  • 김종화;송주영;양석진;전성균
    • 한국응용과학기술학회지
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    • 제27권3호
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    • pp.273-281
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    • 2010
  • Nickel recovery method was studied by the wet process from the catalyst used in hydrogenation process. Nickel content in waste catalyst was about 16%. At the waste catalyst leaching system by the alkaline solution, selective leaching of nickel was possible by amine complex formation reaction from ammonia water and ammonium chloride mixed leachate. The best leaching condition of nickel from mixed leachate was acquired at the condition of pH 8. LIX65N as chelating solvent extractant was used to recover nickel from alkaline leachate. The purity of recovered nickel was higher than 99.5%, and the whole quantity of nickel was recovered from amine complex.

Potentiometric Homogeneous Enzyme-Linked Binding Assays for Riboflavin and Riboflavin Binding Protein

  • 김진목;김혜진;김미정;이동주;한상현;차근식
    • Bulletin of the Korean Chemical Society
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    • 제17권11호
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    • pp.1018-1022
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    • 1996
  • Adenosine deaminase (ADA) has been utilized as the label in devising a potentiometric homogeneous assay for riboflavin and riboflavin binding protein (RBP). The proposed homogeneous assay method employs an ADA-biotin conjugate as the signal generator and an avidin-riboflavin conjugate as the signal modulator in the solution phase. The catalytic activity of the ADA-biotin conjugate is inhibited in the presence of an excess amount of the avidin-riboflavin conjugate, and the observed inhibition is reversed in an amount proportional to the concentration of RBP added. When the analyte riboflavin is added to this mixture of ADA-biotin, avidin-riboflavin and RBP, the activity of the enzyme conjugate is re-inhibited in an amount proportional to the concentration of riboflavin. Since the enzyme label used in this system is ADA, an ammonia-producing enzyme, a potentiometric rather than photometric detection scheme is used to monitor the enzymatic activity in the assay.