• Title/Summary/Keyword: electron transport system

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The Magnetic Field Dependence Properties of Quasi Two Dimensional Electron-piezoelectric Potential Interacting System in GaN and ZnO

  • Lee, S.H.;Sug, J.Y.;Lee, J.H.;Lee, J.T.
    • Journal of Magnetics
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    • v.16 no.4
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    • pp.408-412
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    • 2011
  • We investigated theoretically the magnetic field dependence of the quantum optical transition of qusi 2-Dimensional Landau splitting system, in GaN and ZnO. We apply the Quantum Transport theory (QTR) to the system in the confinement of electrons by square well confinement potential. We use the projected Liouville equation method with Equilibrium Average Projection Scheme (EAPS). Through the analysis of this work, we found the increasing properties of the optical Quantum Transition Line Shapes(QTLSs) which show the absorption power and the Quantum Transition Line Widths(QTLWs) with the magnetic-field in GaN and ZnO. We also found that QTLW, ${\gamma}(B)_{total}$ of GaN < ${\gamma}(B)_{total}$ of ZnO in the magnetic field region B < 25 Tesla.

Quantum Transition Properties of Quasi-Two Dimensional Si System in Electron Deformation Potential Phonon Interacting (전자 포텐셜 변형과 포논 상호작용에 의한 준 이차원 Si 구조의 전도 현상 해석)

  • Lee, Su-Ho;Kim, Young-Mun;Kim, Hai-Jai;Joo, Seok-Min
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.66 no.3
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    • pp.129-134
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    • 2017
  • We investigated theoretically the quantum optical transition properties of Si, in quasi 2-Dimensinal Landau splitting system, based on quantum transport theory. We apply the quantum transport theory (QTR) to the system in the confinement of electrons by square well confinement potential under linearly polarized oscillating field. We use the projected Liouville equation method with Equilibrium Average Projection Scheme (EAPS). In order to analyze the quantum transition, we compare the temperature and the magnetic field dependencies of the QTLW and the QTLS on four transition processes, namely, the intra-leval transition process, the inter-leval transition process, the phonon emission transition process and the phonon absorption transition process.

PRELIMINARY RESULTS OF THE BEAM CONTROL AND DETECTION OF THE KIRAMS ELECTRON MICROBEAM SYSTEM

  • SUN G.M.;KIM E.H.;SONG K.B.;JEONG J.W.;CHOI H.D.
    • Nuclear Engineering and Technology
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    • v.37 no.2
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    • pp.185-190
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    • 2005
  • The Korea Institute of Radiological and Medical Sciences (KIRAMS) electron microbeam system has been built with its prototype components. The system is composed of an electron gun, a beam transport chamber, and a cell image acquisition and positioning stage. Each component has been upgraded through repetitive performance tests for various parametric arrangements. This paper presents the preliminary results of the performance test on the beam control and detection parts of the system.

Effects of iso-Butanol on Photosynthetic Electron Transport Activity in Isolated Spinach Chloroplasts (시금치(Spinacia oleracea L.) 엽록체의 광합성 전자전달 활성에 미치는 iso-Butanol의 영향)

  • 박강은
    • Journal of Plant Biology
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    • v.35 no.3
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    • pp.247-252
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    • 1992
  • The effect of iso-butanol on the electron transport rate of PS I and PS II was investigated in isolated spinach chloroplasts. In photosystem I, the rate of electron transport increased in the presence of 1 to 4% of isobutanol but decreased in 5 to 9% of iso-butanol. But in photosystem II, the rate of electron transport decreased when treated with 0.2 to 1% of iso-butanol. The inhibitory effect of isomers of butanol on PS II electron transport rate increased in the order of 2-butanol, tert-butanol, iso-butanol and I-butanol. This means that PS II activity was affected according to the arrangement of carbon atoms in butanol. The inhibitory effect of iso-butanol reduced when DPC was added in the solution. This means that iso-butanol affects PS II reduction side of thylakoid membrane primarily. The inhibitory effect of iso-butanol was reduced when $Mn^{2+},\;C^{2+}$ or BSA were added in the solution. PS II activity was restored when 1% iso-butanol treated chloroplast solution was diluted to twentyfold or when $Mn^{2+},\;C^{2+}$ or BSA was added to the diluted solution. However, the SDS-PAGE banding pattern of thylakoid membrane proteins was similar even in 2% iso-butanol treated chloroplasts and the control ones. Only in 5% iso-butanol treated chloroplasts these bands were very weak. These observations suggest that low concentrations of iso-butanol releases manganese and calcium ions from chloroplasts and inhibits the electron transport system. This inhibitory effect can be reversible in low concenterations but in high concentrations the inhibitory effect of iso-butanol become irreversible.rsible.

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Comparison of Toxic Effects of Mercury, Copper and Zinc on Photosystem II of Barley Cholroplasts (보리 엽록체의 광계 II에서 수은, 구리 및 아연의 저해효과 비교)

  • 전현식
    • Journal of Plant Biology
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    • v.36 no.3
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    • pp.195-201
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    • 1993
  • The room temperature fluorescence induction of chloroplasts was utilized as a probe to locate the site of inhibition by mercury, copper and zinc on PS II by mercury. Inhibitory effect of Hg2+ on electron transport activity was notable as compared with Cu2+ and Zn2+. At concentrations of HgCl2 over 50 $\mu$M, activities of PS II and whole-chain electron transport decreased more than 70%, while that of PS I decreased about 10~30%. This suggests that PS II is more susceptible to Hg2+ than PS I is. In the presence of diphenylcarbazide (DPC), 50 $\mu$M HgCl2 inhibited the reduction of dichlorophenolindophenol (DCPIP) about 50%. Addition of heavy metals induced marked decrease in maximal variable fluorescence/initial fluorescence [(Fv)m/Fo], but no changes in Fo. With various concentrations of heavy metals, changes of chlorophyll a fluorescence emitted by PS II showed gradual decrease in photochemical quenching (qQ), which indicates an increase in reduced state of electron acceptor, QA. Especially, the addition of HgCl2 caused a notable decrease of qQ. In the presence of 50 $\mu$M CuCl2, energy-depended quenching (qE) was completely reduced, whereas in the presence of 50 $\mu$M CuCl2 and ZnCl2 it was still remained. The above results are discussed on the effects of mercury in relation to water-splitting system and plastoquinone (PQ) shuttle system.

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A Study on the Electron Beam Distribution based on Age-diffusion Model (Age diffusion model을 이용한 전자선량 분포에 대한 연구)

  • Kim, S.H.;Suh, T.S.;Na, Y.J.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.161-163
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    • 1997
  • In this paper, a two-dimensional electron beam dose calculational algorithm implented for use in a two-dimensional radiation therapy planning system is described. The 2-D electron beam calculations have been in use clinically for a few decades. Our algorithm uses Age-diffusion model based int the Boltzman Transport Equation. Our implementation provides convenient user interface associated with electron beam therapy planning and displays radiation dose distribution according to different electron energy on patient images.

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Cyclotron Resonance of the Wannier-Landau Transition System Based on the Ensemble Projection Technique

  • Jung-Il Park
    • Journal of the Korean Magnetic Resonance Society
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    • v.27 no.4
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    • pp.28-34
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    • 2023
  • We study the linear-nonlinear quantum transport theory of Wannier-Landau transition system in the confinement of electrons by a square well confinement potential. We use the projected Liouville equation method with the ensemble density projection technique. We select the dynamic value under a linearly oscillatory external field. We derive the dynamic value formula and the memory factor functions in three electron phonon coupling systems and electron impurity coupling systems of two transition types, the intra-band transitions and inter-band transitions. We obtain results that can be applied directly to numerical analyses. For simple example of application, we analyze the absorption power and line-widths of ZnO, through the numerical calculation of the theoretical result in the Landau system.

Effects of Dimethipin on the Photosynthetic Electron Transport Activity of Isolated Barley Chloroplasts (보리 유식물 분리엽록체의 광합성 전자전달활성에 미치는 Dimethipin의 영향)

  • Lee Joon Sang
    • Korean Journal of Environmental Biology
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    • v.23 no.1
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    • pp.52-56
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    • 2005
  • Eight days grown barley seedlings were treated with dimethipin for 72 hours and then the content of chlorophyll and photosynthetic electron activities of isolated chloroplasts were investigated. At the treatment of 10/sup -5/ M dimethipin the content of chlorophyll was decreased to 33% at 72 hours. Seven days etiolated barley seedlings were exposed to the light while dimethipin was added. At the time of 48 hours' greening chlorophyll content was reduced to 43% at 10/sup -4/M dimethipin and the chlorophyll a/b ratio was increased. In photosynthetic electron transport the activity of PSⅡ+PSⅠ was decreased to 10% at 48 hours and 25% at 72 hours at 10/sup -4/ M dimethipin. In the treatment of 10/sup -4/ M dimethipin the activity of PSⅡ+PSⅠ, except water splitting system was inhibited to 16% at 48 hours and 27% at 72 hours. The activity of PSⅡ was inhibited to 8% at 24 hours, 13% at 48 hours and 18% at 72 hours at 10/sup -4/ M dimethipin. The activity of PSⅠ was inhibited to 4% at 24 hours, 8% at 48 hours and 10% at 72 hours at 10/sup -4/ M dimethipin. In the times of greening of 7 days etiolated barley seedlings the activities of PSⅡ+PSⅠ were reduced to 5, 10, 10 and 11 % at 6, 12, 24, and 48 hours, respectively, at 10/sup -4/ M dimethipin. On the other hand, the activity of PSⅡ+PSⅠ except water splitting system, was not inhibited at all incubated hours in 10/sup -4/M dimethipin and there were no clear changes of the activities of PSⅡ and PSⅠ as compared to the control. Therefore, it could be concluded that dimethipin inhibited the photosynthetic electron activity by affecting the function of chloroplast rather than the synthesis of chloroplast and the inhibited function of chloroplast seems to come from the severe decrease of chlorophyll content.

Effects of Local Anesthetics on Electron Transport and Generation of Superoxide Radicals in Mitochondria (국소마취제가 Mitochondria에서의 전자이동 및 Superoxide Radicals의 생성에 미치는 영향)

  • Lee, Chung-Soo;Shin, Yong-Kyoo;Lee, Kwang-Soo
    • The Korean Journal of Pharmacology
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    • v.23 no.2
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    • pp.113-121
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    • 1987
  • Local anesthetics were investigated for their effects on mitochondrial electron transport system, production of superoxide radical from submitochondrial particles and malondialdehyde production through lipid per oxidation. Local anesthetics had various effects on activities of enzymes in electron transport chain. The activities of NADH dehydrogenase, NADH oxidase and NADH-ubiquinone oxidoreductase were effectively inhibited by lidocaine, procaine and dibucaine but slightly influenced by cocaine. The activities of succinate dehydrogenase, succinate-cytochrome c oxidoreductase and succinate-ubiquinone oxidoreductase were inhibited by lidocaine and dibucaine, but the succinate oxidase activity was stimulated by local anesthetics. Both dihydroubiquinone-cytochrome c oxidoreductase and cytochrome c oxidase activities were inhibited by local anesthetics. In these reactions, the response of Complex I segment to local anesthetics was greater than other Complex segments. Local anesthetics inhibited both the superoxide production from submitochondrial particles supplemented with succinate or NADH and the enhanced production of superoxide radicals by antimycin. The malondialdehyde production by oxygen free radicals was inhibited by local anesthetics. These results suggest that the inhibition of superoxide and malondialdehyde production caused by local anesthetics may be brought by suppression of the electron transport in mitochondria at sites in or near complex I segment.

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The Effects of Food Azo Dyes on the Hepatic Microsomal Mixed Function Oxidase System in Rats (식용 Azo색소가 Hepatic Microsomal Mixed Function Oxidase System에 미치는 영향)

  • 윤혜정;김백화
    • YAKHAK HOEJI
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    • v.31 no.6
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    • pp.361-369
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    • 1987
  • The four azo dyes such as Amaranth (FD & C Red No. 2), Tartrazine (FD & C Yellow No. 4), sunset Yellow (FD & C Yellow No. 5) and Allura red (FD & C Red No. 40) are currently employed as a food additives in Korea. In this study, the effects of these azo dyes on the hepatic microsomal mixed function oxidase systems in Rats. (i.e., Cyt. P-450, Cyt. b$_5$, NADPH cyt. c-reductase and azo reductase) were investigated. Furthermore, to determine the relationship among the electron transport systems, each level of azo reductase, Cyt. P-450 and NADPH cyt. c-reductase was measured upon the administration of phenobarbital (known as an inducer of Cyt. P-450), 3-methylcholanthrene (Known as an inducer of Cyt. P-448), CoCl$_2$ (inhibitor on Cyt. P-450) or $CCl_4$ (inhibitor on Cyt. P-450). The results of these studies are as follows; (1) The levels of Cyt. P-450 and Cyt. b$_5$ were decreased upon the administration of these azo dyes. (2) When the level of Cyt. P-450 was decreased, the azo reductase activity was also decreased. (3) These azo dyes did not show any significant effect on the level of NADPH cyt. c-reductase. (4) The administration of 3-methylcholanthrene resulted in the elevation of azo reductase activity. The 3-methylcholanthrene may be responsible for the induction of CO-insensitive electron transport system.

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