• Title/Summary/Keyword: proton reaction

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Theoretical study of cross sections of proton-induced reactions on cobalt

  • Yigit, Mustafa
    • Nuclear Engineering and Technology
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    • v.50 no.3
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    • pp.411-415
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    • 2018
  • Nuclear fusion may be among the strongest sustainable ways to replace fossil fuels because it does not contribute to acid rain or global warming. In this context, activated cobalt materials in corrosion products for fusion energy are significant in determination of dose levels during maintenance after a coolant leak in a nuclear fusion reactor. Therefore, cross-section studies on cobalt material are very important for fusion reactor design. In this article, the excitation functions of some nuclear reaction channels induced by proton particles on $^{59}Co$ structural material were predicted using different models. The nuclear level densities were calculated using different choices of available level density models in ALICE/ASH code. Finally, the newly calculated cross sections for the investigated nuclear reactions are compared with the experimental values and TENDL data based on TALYS nuclear code.

Development of High-Efficient Small Euel Cells : I. Synthesis of Organic-Inorganic Nanocomposite Electrolyte Membranes (고효율 소형 연료전지의 개발 : I.유기-무기 나노복합 전해질막의 합성)

  • Park, Yong-Il;Moon, Joo-Ho;Kim, Hye-Kyung;Kim, Suk-Hwam
    • Journal of the Korean Ceramic Society
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    • v.42 no.1
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    • pp.50-55
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    • 2005
  • New fast proton-conducting organic-inorganic nanocomposite membranes were successfully fabricated using polymer matrix obtained through proper oxidation of thiol ligands in (3-Mercaptopropyl) trimethoxysilane (MPTS) and hydrolysis/condensation reaction of (3-glycidoxypropyl) trimethoxysilane (GPTS). The obtained nanocomposite membranes showed relatively hirh proton-conductivity over $10^{-2}S/cm$ at $ 25^{circ}C$. The proton conductivities of the fabricated composite membranes increased up to $3.6{\times}10^{-1}$ S/cm cm by increasing temperature and relative humidity to $70^{circ}C$ and 100 $100RH\%$. The high proton conductivity of the composites Is due to the proton conducting path through the GPTS-derived 'pseudo-polyethylene oxide 'network in which sulfonic acid ligands work as a proton donor.

Visualization of two-phae flow by using transparent Proton Exchange Membrane Fuel Cell (고분자 전해질 연료전지 가시화 장치를 이용한 이상유동 현상 관찰)

  • Lee, Dong-Ryul;Bae, Joong-Myeon
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.374-377
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    • 2009
  • The operating temperature of Proton Exchange Membrane Fuel Cell (PEMFC) usually has to be limited under $100^{\circ}C$ to maintain the proper ionic conductivity. Therefore, the only product from reaction, water, is in the liquid phase. Two-phase flow makes the flow phenomenon in the channel difficult to understand and predict. Water blocking in the PEMFC channel or the pore of Gas Diffusion Layer (GDL), called flooding, is known as the main effect of PEMFC degradation. To analyze two-phase flow, the PEMFC with transparent acrylic plate was used. Two-phase flow patterns were observed by varying the current density. When the PEMFC is mounted horizontally, water in the cathode is mainly transported on the interface between the channel and GDL.

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Photophysical Model of 10-Hydroxybenzo[h]quinoline: Internal Conversion and Excited State Intramolecular Proton Transfer

  • Lee, Junghwa;Joo, Taiha
    • Bulletin of the Korean Chemical Society
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    • v.35 no.3
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    • pp.881-885
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    • 2014
  • Photophysics of 10-hydroxybenzo[h]quinoline (HBQ) has been in controversy, in particular, on the nature of the electronic states before and after the excited state intramolecular proton transfer (ESIPT), even though the dynamics and mechanism of the ESIPT have been well established. We report highly time resolved fluorescence spectra over the full emission frequency regions of the enol and keto isomers and the anisotropy in time domain to determine the accurate rates of the population decay, spectral relaxation and anisotropy decay of the keto isomer. We have shown that the ~300 fs component observed frequently in ESIPT dynamics arises from the $S_2{\rightarrow}S_1$ internal conversion in the reaction product keto isomer and that the ESIPT occurs from the enol isomer in $S_1$ state to the keto isomer in $S_2$ state.

A modified analytical model of proton Bragg curves

  • Takizawa, Ken-ichi;Yoshihisa Takada;Takeharu Nakashima;Syunsuke Kohno;Yuhsuke Kobayashi
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.186-188
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    • 2002
  • An improved analytical model has been developed to calculate an accurate Bragg curve of proton beam with an arbitrary energy. The model takes the transport of the secondary protons produced by the nuclear inelastic reactions into account. By the model, measured Bragg curves of proton beams with ten energies between 250 and 70 MeV are reproduced well. It will serve to obtain fundamental data for treatment planning and for energy scanning.

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Synthesis of N-[2-(3,5-dimethyl-4-methoxypyridyl)alkyl]oxazolidinone Analogues and Evaluation of their Proton Pump Enzyme Inhibitions (N-[2-(3,5-디메틸-4-메톡시피리딜)알킬]옥사졸리디논 유도체의 합성 및 프로톤 펌프 효소 저해 효과)

  • Yoon, Sung-Hwa;Kim, Do-Young;Hwang, Sung-Kwan
    • YAKHAK HOEJI
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    • v.41 no.2
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    • pp.174-180
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    • 1997
  • Four oxazolidinone analogues(6, 7, 8, 9), which are isosters of 5, were synthesized by the reaction of 2-chloroalkyl-3,5-dimethyl-4-methoxypyridine with the corresponding benzox azolidinone or oxazolidinone, respectively, and were evaluated for their inhibitory activities toward proton pump enzyme under in vitro condition. Isosteric substitution of the benzothiazolidine moiety in 5 with benzoxazolidinone rendered the molecule relatively inactive.

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Application of Excited-State Intramolecular Proton Transfer (ESIPT) Principle to Functional Polymeric Materials

  • Park, Sang-Hyuk;Kim, Se-Hoon;Seo, Jang-Won;Park, Soo-Young
    • Macromolecular Research
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    • v.16 no.5
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    • pp.385-395
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    • 2008
  • Synthesis and properties of novel excited-state intramolecular proton transfer (ESIPT) materials, recently developed in our group, are described. Highly efficient ESIPT reaction, achieved in polyquinolines, polybenzoxazoles, and oxadiazole and imidazole derivatives possessing an intramolecular tautomerizable hydrogen bond, has been investigated theoretically and experimentally. It is demonstrated that unique properties arising from the ESIPT process (large Stokes' shift, no self-absorption, and easy population inversion, etc.) make it possible to produce advanced polymer devices for lasing, optical storage, and electroluminescence.

Study of Frozen Molecular Surfaces by $Cs^{+}$ Reactive ion Scattering and tow-Energy Secondary ton Mass Spectrometry

  • Park, S.-C.;Kang, H.
    • Journal of Korean Vacuum Science & Technology
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    • v.6 no.1
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    • pp.30-35
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    • 2002
  • We show that a combined technique of Cs$^{+}$ reactive ion scattering (Cs$^{+}$ RIS) and low-energy secondary ion mass spectrometry (LESIMS) provides a powerful means for probing molecular films and their surface reactions. Simple molecules, including HCI, NH$_3$, D$_2$O, and their mixtures, were deposited into a thin film of several monolayer thickness on Ru(001) at low temperature in vacuum, and the surface was characterized by Cs$^{+}$ RIS and LESIMS. On pure films, D$_2$O, HCI, and NH$_3$ existed in the corresponding molecular states. When HCI and NH$_3$ were co-deposited, ammonium ion(NH$_4$$^{+}$) was readily formed by proton transfer from HCI to NH$_3$. In the presence of water molecules, HCI ionized first to hydronium ion(H$_3$O$^{+}$), which subsequently transferred proton to NH$_3$ to form NH$_4$$^{+}$. The proton transfer, however, did not occur to a completion on ice, in contrast to the complete reaction in aqueous solutions.s solutions.

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