• Title/Summary/Keyword: Protons

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Multiconfiguration Molecular Mechanics Studies for the Potential Energy Surfaces of the Excited State Double Proton Transfer in the 1:1 7-Azaindole:H2O Complex

  • Han, Jeong-A;Kim, Yong-Ho
    • Bulletin of the Korean Chemical Society
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    • v.31 no.2
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    • pp.365-371
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    • 2010
  • The multiconfiguration molecular mechanics (MCMM) algorithm was used to generate potential and vibrationally adiabatic energy surfaces for excited-state tautomerization in the 1:1 7-azaindole:$H_2O$ complex. Electronic structures and energies for reactant, product, transition state were computed at the CIS/6-31G(d,p) level of theory. The potential and vibrationally adiabatic energies along the reaction coordinate were generated step by step by using 16 high-level Shepard points, which were computed at the CIS/6-31G(d,p) level. This study shows that the MCMM method was applied successfully to make quite reasonable potential and adiabatic energy curves for the excited-state double proton transfer reaction. No stable intermediates are present in the potential energy curve along the reaction coordinate of the excited-state double proton transfer in the 1:1 7-azaindole:$H_2O$ complex, indicating that these two protons are transferred concertedly. The change in the bond distances along the reaction coordinate shows that two protons move very asynchronously to make an $H_3O^+$-like moiety at the transition state.

THE QUEST FOR COSMIC RAY PROTONS IN GALAXY CLUSTERS

  • PFROMMER C.;ENSSLIN T. A.
    • Journal of The Korean Astronomical Society
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    • v.37 no.5
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    • pp.455-460
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    • 2004
  • There have been many speculations about the presence of cosmic ray protons (CRps) in galaxy clusters over the past two decades. However, no direct evidence such as the characteristic $\gamma$-ray signature of decaying pions has been found so far. These pions would be a direct tracer of hadronic CRp interactions with the ambient thermal gas also yielding observable synchrotron and inverse Compton emission by additionally produced secondary electrons. The obvious question concerns the type of galaxy clusters most likely to yield a signal: Particularly suited sites should be cluster cooling cores due to their high gas and magnetic energy densities. We studied a nearby sample of clusters evincing cooling cores in order to place stringent limits on the cluster CRp population by using non-detections of EGRET. In this context, we examined the possibility of a hadronic origin of Coma-sized radio halos as well as radio mini-halos. Especially for mini-halos, strong clues are provided by the very plausible small amount of required CRp energy density and a matching radio profile. Introducing the hadronic minimum energy criterion, we show that the energetically favored CRp energy density is constrained to $2\%{\pm}1\%$ of the thermal energy density in Perseus. We also studied the CRp population within the cooling core region of Virgo using the TeV $\gamma$-ray detection of M 87 by HEGRA. Both the expected radial $\gamma$-ray profile and the required amount of CRp support this hadronic scenario.

STABILITY OF THE TWO-TEMPERATURE ACCRETION DISK

  • PARK MYEONG-GU
    • Journal of The Korean Astronomical Society
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    • v.28 no.1
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    • pp.97-107
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    • 1995
  • The stability of the geometrically thin, two-temperature hot accretion disk is studied. The general criterion for thermal instability is derived from the linear local analyses, allowing for advective cooling and dynamics in the vertical direction. Specifically, classic unsaturated Comptonization disk is analysed in detail. We find five eigen-modes: (1) Heating mode grows in thermal time scale, $(5/3)({\alpha}{\omega})^{-1}$, where alpha is the viscosity parameter and w the Keplerian frequency. (2) Cooling mode decays in time scale, $(2/5)(T_e/T_i)({\alpha}{\omega})^{-1}$, where $T_e\;and\;T_i$ are the electron and ion temperatures, respectively. (3) Lightman-Eardley viscous mode decays in time scale, $(4/3)(\Lambda/H)^2({\alpha}{\omega})^{-1}$, where $\Lambda$ is the wavelength of the perturbation and H the unperturbed disk height. (4) Two vertically oscillating modes oscillate in Keplerian time scale, $(3/8)^{1/2}\omega^{-1}$ with growth rate $\propto\;(H/\Lambda)^2$. The inclusion of dynamics in the vertical direction does not affect the thermal instability, adding only the oscillatory modes which gradually grow for short wavelength modes. Also, the advective cooling is not strong enough to suppress the growth of heating modes, at least for geometrically thin disk. Non-linear development of the perturbation is followed for simple unsaturated Compton disk: depending on the initial proton temperature perturbation, the disk can evolve to decoupled state with hot protons and cool electrons, or to one-temperature state with very cool protons and electrons.

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PSYCHO-PHYSICS

  • Oh, Hung-Kuk
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2000.04a
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    • pp.35-38
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    • 2000
  • Conventional atom model must be criticized on the following four points.(1) natural motions between positive and negative entities are not circular motions but linear going and returning ones, for examples sexual motion, tidal motion, day and night etc.(2) Potential energy generation was neglected when electron changes its orbit from outer one to inner one. The hv is the kinetic energy of the photo-electron. The total energy difference between orbits comprises kinetic and potential energies. (3) The structure of the space must be taken into consideration because the properties of the electron do not changed during the transition from outer orbit to inner one even though it produces photon. (4) Total energy conservation law applies to the energy flow between mind and matter because we daily experiences a interconnection between mind and body.New atomic model 9the crystallizing $\pi$-bonding) was proposed in the journal of material processing technology since 1997 for the explanation of the mechanical behaviors in terms of physics. $\prod$-ray physics proved that the electrons can come out from in the nucleus and modern chemistry corresponds to the $\pi$-bonding by the nuclear electrons. The $\pi$-bonding structure of the protons outside the nucleus is that electrons move between protons of the different atoms. The perception step and the characteristic frequency in signal transduction is due to the accumulation of the $\pi$-rays outside of the proton before their absorption to the nucleus.

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PSYCHO-PHYSICS

  • Oh, Hung-Kuk
    • Proceedings of the Korean Society for Cognitive Science Conference
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    • 2000.05a
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    • pp.71-75
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    • 2000
  • Conventional atom model must be criticized on the following four points. (1) Natural motions between positive and negative entities are not circular motions but linear going and returning ones, for examples sexual motion, tidal motion, day and night etc. (2) Potential energy generation was neglected when electron changes its orbit from outer one to inner one. The hv is the Kinetic energy of the photo-electron. The total energy difference between orbits comprises kinetic and potential energies. (3) The structure of the space must be taken into consideration because the properties of the electron do not change during the transition form outer orbit to inner one even though it produces photon. (4) Total energy conservation law applies to the energy flow between mind and matter because we daily experiences a interconnection between mind and body. New atomic model (the crystallizing $\pi$-bonding) was proposed in the journal of material processing technology since 1997 for the explanation of the mechanical behaviors in terms of physics. $\prod$-ray physics proved that the electrons can come out from in the nucleus and modern chemistry corresponds to the $\pi$-bonding by the nuclear electrons. The $\pi$-bonding structure of the protons outside the nucleus is that electrons move between protons of the different atoms. The perception step and the characteristic frequency in signal transduction is due to the accumulation of the $\pi$-rays outside fo the proton before their absorption to the nucleus.

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Study on NMR Measurment of Flowing Water by a Separated Detector (분리형 감지기를 이용한 흐르는 물의 핵자기공명 측정연구)

  • ;;;;V. Ya. Shifrin
    • Journal of the Korean Magnetics Society
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    • v.5 no.3
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    • pp.165-170
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    • 1995
  • NMR measurement has been studied for protons in pre-polarized flowing water by a separated detector working at high field far away from the measured field region where the transition of protons is occurred by the pertur-bation of RF energy. The conditions for NMR signal were optimized on the amplitude and frequency of modulation field, the RF field of detector, water speed, and RF field at the measured field region. The NMR signal with the full width of 320 nT at the half maximum in Lorentzian curve and with signal to noise ratio of 10.5 was measured in the range from a few ${\mu}T$ to mT, and its shape and amplitude were independent of the measured field intensity and its uniformity.

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Cerium Pyrophosphate-based Proton-conducting Ceramic Electrolytes for Low Temperature Fuel Cells

  • Singh, Bhupendra;Kim, Ji-Hye;Im, Ha-Ni;Song, Sun-Ju
    • Journal of the Korean Ceramic Society
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    • v.51 no.4
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    • pp.248-259
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    • 2014
  • Acceptor-doped cerium pyrophosphates have shown significant proton conductivity of > $10^{-2}Scm^{-1}$ in the range of $100-300^{\circ}C$ and are considered promising candidates for use as electrolytes in proton-conducting, ceramic electrolyte fuel cells (PCFCs). But, cerium pyrophosphates themselves do not have structural protons, and protons incorporate into their material bulk only as impurities on exposure to a hydrogen-containing atmosphere. However, proton incorporation and proton conduction in these materials are expected to be affected by factors such as the nature (ionic size and charge) and concentration of the aliovalent dopant, processing history (synthesis route and microstructure), and the presence of residual phosphorous phosphate ($P_mO_n$) phases. An exact understanding of these aspects has not yet been achieved, leading to large differences in the magnitude of proton conductivity of cerium pyrophosphates reported in various studies. Herein, we systematically address some of these aspects, and present an overview of factors affecting proton conductivity inacceptor-doped $CeP_2O_7$.

Occurrence of cis-4-Tetradecenoic Acid in the Oils of Kernels of Lindera erythrocarpa Seeds, as a Major Component

  • Kim, Seong-Jin;Joh, Yong-Goe
    • Food Science and Biotechnology
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    • v.15 no.1
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    • pp.107-111
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    • 2006
  • Kernel oils of Lindera erythrocarpa seeds had high level of unusual fatty acid. Picolinyl ester of this unknown fatty acid showed molecular ion at m/z = 317 with other diagnostic ions such as m/z = 151, 191 (40 amu between two peaks), 204, and 218 on GC-MS. Characteristic peak at $720\;cm^{-1}$ appeared in IR spectrum. In $^1H-NMR$ spectrum both methylene protons at C-3 and C-6 resonated at ${\delta}2.309$ and ${\delta}2.012$, and methine protons of double bond resonated in lower magnetic field centered at ${\delta}5.296$ (C-4) and ${\delta}5.387$ (C-5) as multiplet (J = 9.7Hz). In $^{13}C-NMR$, signals at ${\delta}22.669$ and ${\delta}27.048$ were due to C-3 and C-6 of ${\delta}^4$-monoenoic acid. Results obtained from spectroscopic measurements confirmed unknown fatty acid as cis-4-tetradecenoic acid (cis-4-$C_{14:1}$). Main fatty acid components of oils were cis-4-$C_{14:1}$ (44.5-45.1%), oleic acid ($C_{18:1}$), 20.4-21.3%), and lauric acid ($C_{12:0}$, 11.6-12.4%), along with trace amounts of cis-4-$C_{12:1}$ and cis-4-$C_{16:1}$.

Glutathione Conjugates of 2- or 6-Substituted 5,8-Dimethoxy-1,4-Naphthoquinone Derivatives : Formation and Structure

  • Zheng, Xiang-Guo;Kang, Jong-Seong;Kim, Yong;You, Young-Jae;Jin, Guang-Zhu;Ahn, Byung-Zun
    • Archives of Pharmacal Research
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    • v.22 no.4
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    • pp.384-390
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    • 1999
  • Thirty-four glutathione conjugates of 5,8-dimethoxy-1,4-naphthoquinones (DMNQ) were synthesized and their structure was determined. The yield of GSH conjugate was dependent on size of alkyl group; the longer the size of alkyl group was, the lower was the yield. It was also found that the length of alkyl side chain influenced the chemical shift of quinonoid protons; the quinonoid protons of 2-glutathionyl DMNQ derivatives with R=H to propyl, 6.51-6.59 ppm vs. other ones with R=butyl to heptyl, 6.64-6.68 ppm. this was explained to be due to a folding effect of longer alkyl group. Glutathione (GSH) reacted with DMNQ derivative first to form a 1,4-adduct (2- or 3-glutathionyl-1,4-dihydroxy-5,8-dimethoxynaphthalenes) and then the adduct was autooxidized to 2- or 3-glutathionyl-DMNQ derivatives. Moreover, GSH reduced DMNQ derivatives to their hydrogenated products. It was suggested that such an organic reaction might play an important role for a study of metabolism or toxicity of DMNQ derivative sin the living cells.

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An Amperometric Proton Selective Sensor with an Elliptic Microhole Liquid/Gel Interface for Vitamin-C Quantification

  • Faisal, Shaikh Nayeem;Hossain, Md. Mokarrom;Lee, Hye-Jin
    • Journal of Electrochemical Science and Technology
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    • v.1 no.2
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    • pp.121-126
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    • 2010
  • An amperometric ascorbic acid selective sensor utilizing the transfer reaction of proton liberated from the dissociation of ascorbic acid in aqueous solution across an elliptic micro-hole water/organic gel interface is demonstrated. This redox inactive sensing platform offers an alternative way for the detection of ascorbic acid to avoid a fouling effect which is one of the major concerns in redox based sensing systems. The detection principle is simply measuring the current change with respect to the assisted transfer of protons by a proton selective ionophore (e.g., ETH 1778) across the micro-hole interface between the water and the polyvinylchloride-2-nitrophenyloctylether gel phase. The assisted transfer reaction of protons generated from ascorbic acid across the polarized micro-hole interface was first characterized using cyclic voltammetry. An improved sensitivity for the quantitative analysis of ascorbic acid was achieved using differential pulse stripping voltammetry with a linear response ranging from 1 to $100\;{\mu}M$ concentrations of ascorbic acid. As a demonstration, the developed sensor was applied for analyzing the content of vitamin-C in different types of commercial pharmaceutical tablets and syrups, and a satisfactory recovery from these samples were also obtained.