• 제목/요약/키워드: Electron donor

검색결과 370건 처리시간 0.026초

Porous Organic-inorganic Hybrids for Removal of Amines

  • Cho, Sung-Youl;Kim, Na-Ri;Cao, Guozhong;Kim, Joong-Gon;Chung, Chan-Moon
    • Bulletin of the Korean Chemical Society
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    • 제27권3호
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    • pp.399-402
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    • 2006
  • Porous organic-inorganic hybrids have been prepared from tetraethylorthosilicate (TEOS) and organosilane precursors by sol-gel method. Two organosilanes, 3-(2,4-dinitrophenylamino)propyltriethoxysilane (DNPTES) and N-[[(2-nitrophenyl)methoxy]carbonyl]-3-triethoxysilylpropylamine (NPTES) were used to incorporate electron-accepting (di)nitrophenyl groups into the hybrids. The hybrids were characterized by FT-IR spectroscopy and elemental analysis, and their pore characteristics were studied by nitrogen sorption porosimetry. Surface area of the hybrids ranged from 563 to 770 $m^2$/g, pore volume, 0.23-0.30 $cm^3$/g, and porosity, 35-41%. It was demonstrated by UV-vis spectroscopy that aniline, ethylenediamine, and 1-aminonaphthalene could be removed from their hexane solutions in the presence of the hybrid powders. The removal of amines is attributable to donor-acceptor interaction between the electron-donating amines and electron-accepting (di)nitrophenyl moiety.

Oxygen-dependent Respiration and Proteon Extrusion in Wolinella Succinogenes

  • Han, Yeong-Hwan
    • 미생물학회지
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    • 제30권6호
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    • pp.432-437
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    • 1992
  • When $H^{2}$ was provided as the electron donor, optimum $O_{2}$ levels for growth of Wolinella succinogenes ATCC 29543 were 2% and 8% on brucella agar and in brucella broth, respectively. No growth occurred under 21% $O_{2}$, and scant or no growth occurred under anaerobic condition. $O_{2}$ uptake was inhibited by cyanide and 2-heptyl-4-hydroxyquinoline N-oxide. Protons were translocated out of the cell when oxygen was used as the terminal electron accetor. The $H^{+}$/O ratio with $H_{2}$ and formate as an electron donor were 1, 97 and 1.49, respectively. Proton translocation was inhibited by the protonophore carbonylcyanide m-chlorophenylhydrazone.e.

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ZnO 바리스터의 TSC 특성 (Characteristics of Thermally Stimulated Current in the ZnO varister)

  • 안용모;이성일;이상석;박춘배;이준용
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1989년도 춘계학술대회 논문집
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    • pp.101-104
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    • 1989
  • Thermal Electet of the Zinc Oxide varistor has been studied in the temperature range of -130~200[$^{\circ}C$] and the electric field of 6[kV/m]. It appears that there are four peaks of thermally stimulated current; $\alpha$, $\beta$, ${\gamma}$ and $\delta$ spectra appearing at the temperature range of 160, 130, 20 and -30[$^{\circ}C$], respectively. It seems that the origin of $\alpha$, $\beta$, ${\gamma}$ and $\delta$ peaks are associated with the depolarization of donor ions in the depletion layer, the detrapping of trapped electron in the surface, the detrapping of trapped electron in the donor level and the detrapping of trapped electron between grain and intergranular, respectively.

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ZnO 바리스터의 열 일렉트렛트 (Thermal Electret of the ZnO varistor)

  • 안용모;이상석;박승협;홍진웅;이성백;이준웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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    • pp.817-820
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    • 1988
  • Thermal Electet of the Zinc Oxide varistor has been studied in the temperature range of -130${\sim}200[^{\circ}C]$ and the electric field of 6[kV/m]. It appears that there are four peaks of thermally stimulated current; ${\alpha},\;{\beta},\;{\gamma}$ and ${\delta}$ spectra appearing at the temperature range of 160, 130, 20 and $-30[^{\circ}C]$, respectively. It seems that the origins of ${\alpha},\;{\beta},\;{\gamma}$ and ${\delta}$ peaks are associated with the depolarization of donor ions in the depletion layer, the detrapping of trapped electron in the surface, the detrapping of trapped electron in the donor level and the detrapping of trapped electron between grain and intergranular, respectively.

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Noncovalently Linked Zinc Porphyrin-Ru(bpy)3 Dyad Assembled via Axial Coordination

  • Kim, Dol;Shin, Eun-Ju
    • Bulletin of the Korean Chemical Society
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    • 제24권10호
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    • pp.1490-1494
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    • 2003
  • Noncovalently linked electron donor-acceptor dyad consisting of zinc tetratolylporphyrin and pyridine appended ruthenium trisbipyridine comlex was prepared, via axial coordination of pyridine moiety in ruthenium trisbipyridine complex on zinc tetratolylporphyrin. For the purpose of comparison, axial coordination of pyridine-appended 2,2'-bipyridine on zinc tetratolylporphyrin was also investigated. The Kvalues were detemined based on absorption of fluorescence studies. The fluorescence of zinc teratolylporphrin was efficiently quenched upon axial coordination of pyridine moiety, prbably due to the photoinduced electron transfer from zinc tetrtolylporphyrin to ruthenium trisbipyridine, supported by free enegy estimation.

제초제 Paraquat의 전자수용 및 방출에 대한 영향 (Effect of Herbicide Paraquat on Electron Donor and Acceptor)

  • 김미림;최경호
    • 생명과학회지
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    • 제15권2호
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    • pp.311-315
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    • 2005
  • Pparaquat의 전자수용 및 방출에 대한 작용을 검토한 결과는 다음과 같다. Rat mitocondria분산액에 paraquat를 첨가하였을 때 반응액이 청색으로 변색되었으며 Aluminium 박 또는 동전극을 장치한 photo cell중에서 paraquat에 전류를 통한 경우에도 음극에서부터 청색으로 변색되기 시작하여 660 nm에서 높은 홉광도를 나타내었다. 이 착색반응은 반응액에 산소를 첨가함으로서 탈색되었다. Paraquat에 $H^+$을 첨가하고 전류를 통한 결과 340 nm에서의 홉광도가 증가되었으며 경시적인 흡광도 증가의 모양은 $NAD^+$에 전류를 통한 경우와 거의 일치하였다. 이상의 결과로부터 paraquat가 전자를 수용 또는 방출할 수 있음이 확인되었고 이러한 paraquat의 작용이 생체내에 이화작용에서 생성되는 전자를 포획하고 산소에 직접 넘겨줌으로써 cytochrome 호흡쇄로의 단계별 전자전달계가 차단되어 급성독성을 일으키는 요인으로 추정된다.

시화호 저니(Sediment)에서의 유기물 및 중금속 농도와 혐기성호흡세균과의 상관관계 (Relationship between the Organic Content, Heavy Metal Concentration and Anaerobic Respiration Bacteria in the Sediments of Shiwha-ho)

  • 현문식;장인섭;박형수;김병홍;김형주;이홍금;권개경
    • 한국미생물·생명공학회지
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    • 제27권3호
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    • pp.252-259
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    • 1999
  • Anoxic sediments collected from Shiwha-ho area were used to find the relationship between the heavy-metal, organic content and anaerobic respiration bacteria by most probable number (MPN) method. Analysis of the sediments showed that COD content was higher in the sediments collected from Ansan-cheon and Shiwha-ho than those collected from sea area nearby. Particularly noticeable was the fact that heavy metal concentration was much higher in the sediments of Shiwha-ho area contaminated by heavy-metal, although they were rich in electron donor and electron acceptor for Fe(III)-reducing bacteria using lactate as an electron donor was in the range of 1.1$\times$106-4.6$\times$107MPNs/ml in the sediments collected from the sea-side of the lake, which were lower in heavy-methal concentration and higher in Fe-Mn content than those from other region. The number of Fe(III)-reducing bacteria using acetate as an electron donor was in the rang eof 4.3$\times$102-8.1$\times$105MPNs/ml in the same sediments. Chromate-reducing bacteria were more populated(4.6$\times$104-8.1$\times$105MPNs/ml) in the sediments contaminated by heavy metals. The number of sulfate-reducing bacteria wee counted in the sediments collected from the more contaminate inner-side than those from the sea-side of the lake.

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전극을 전자공여체로 이용한 생물전기화학공정에서의 염소화페놀의 탈염소화 (Reductive Dechlorination of Chlorinated Phenols in Bio-electrochemical Process using an Electrode as Electron Donor)

  • 전현희;박대원
    • KSBB Journal
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    • 제22권3호
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    • pp.134-138
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    • 2007
  • 미생물이 환원된 전극을 전자공여체로 이용하고, 염소화페놀을 전자수용체로 이용하는 새로운 혐기성 호흡의 생물전기화학공정을 통해 2,6-DCP을 탈염소시킬 수 있는지를 조사하였다. 이를 위해 전류의 유무에 따른 농도변이와 전극 표면을 주사전자현미경으로 관찰한 결과, 전류가 흐르는 경우에만 염소화페놀이 완전히 제거됨을 보였으며, 전극표면에 생물막이 형성된 것을 통해서 전극이 전자공여체 역할을 함으로서 탈염소시킬 수 있음을 증명하였다. 또한, 본 연구의 생물전기화학공정을 통해서 고농도의 염소화페놀 적용도 가능한지를 조사하고 Monod식을 이용하여 최대 탈염소화 속도를 산정하였는데 본 실험의 최대초기농도인 $457mg/{\ell}$까지 분해가 가능하였으며, 최대탈염소화 속도는 $5.95mg/{\ell}$-h($cm^2$ (electrode surface area))이었다.

Synthesis and Photovoltaic Properties of Alternating Conjugated Polymers Derived from Thiophene-Benzothiadiazole Block and Fluorene/Indenofluorene Units

  • Li, Jianfeng;Tong, Junfeng;Zhang, Peng;Yang, Chunyan;Chen, Dejia;Zhu, Yuancheng;Xia, Yangjun;Fan, Duowang
    • Bulletin of the Korean Chemical Society
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    • 제35권2호
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    • pp.505-512
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    • 2014
  • A new donor-accepter-donor-accepter-donor (D-A-D-A-D) type 2,1,3-benzothiadiazole-thiophene-based acceptor unit 2,5-di(4-(5-bromo-4-octylthiophen-2-yl)-2,1,3-benzothiadiazol-7-yl)thiophene ($DTBTTBr_2$) was synthesized. Copolymerized with fluorene and indeno[1,2-b]fluorene electron-rich moieties, two alternating narrow band gap (NBG) copolymers PF-DTBTT and PIF-DTBTT were prepared. And two copolymers exhibit broad and strong absorption in the range of 300-700 nm with optical band gap of about 1.75 eV. The highest occupied molecular orbital (HOMO) energy levels vary between -5.43 and -5.52 eV and the lowest unoccupied molecular orbital (LUMO) energy levels range from -3.64 to -3.77 eV. Potential applications of the copolymers as electron donor material and $PC_{71}BM$ ([6,6]-phenyl-$C_{71}$ butyric acid methyl ester) as electron acceptors were investigated for photovoltaic solar cells (PSCs). Photovoltaic performances based on the blend of PF-DTBTT/$PC_{71}BM$ (w:w; 1:2) and PIF-DTBTT/$PC_{71}BM$ (w:w; 1:2) with devices configuration as ITO/PEDOT: PSS/blend/Ca/Al, show an incident photon-to-current conversion efficiency (IPCE) of 2.34% and 2.56% with the open circuit voltage ($V_{oc}$) of 0.87 V and 0.90 V, short circuit current density ($J_{sc}$) of $6.02mA/cm^2$ and $6.12mA/cm^2$ under an AM1.5 simulator ($100mA/cm^2$). The photocurrent responses exhibit the onset wavelength extending up to 720 nm. These results indicate that the resulted narrow band gap copolymers are viable electron donor materials for polymer solar cells.